1043-00002 · Ironhaven Data Centers LLC · Engagement & Administration

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CALDERWOOD & HARKNESS LLP Attorneys at Law

425 Lexington Avenue New York, NY 10017

Telephone: (212) 554-7000 Facsimile: (212) 554-7001 www.calderwoodharkness.com

March 12, 2025

VIA EMAIL AND U.S. MAIL

Mr. Marcus Thorne Chief Executive Officer Ironhaven Data Centers LLC 44680 Prentice Drive, Suite 200 Ashburn, VA 20147

Re: Engagement of Calderwood & Harkness LLP — Stonebridge Data Center Campus Development Matter No. 1043-00002

Dear Mr. Thorne:

1. Introduction and Engagement Confirmation

Calderwood & Harkness LLP ("C&H" or the "Firm") is pleased to confirm its engagement by Ironhaven Data Centers LLC ("IHDC," "Ironhaven," or the "Client"), a Delaware limited liability company headquartered in Ashburn, Virginia, to represent the Client in connection with the development of a ground-up data center campus known as the Stonebridge Data Center Campus (the "Stonebridge Campus" or the "Project"), to be located in Loudoun County, Virginia. This engagement is effective as of March 12, 2025.

As we have discussed, the Project is a large-scale, multi-building data center development with a total anticipated project budget of approximately Six Hundred Million Dollars ($600,000,000). The Project involves a number of complex and interrelated legal workstreams, including but not limited to land assemblage from multiple sellers, entitlements and permitting through Loudoun County, the negotiation and execution of an engineering, procurement, and construction ("EPC") contract, the negotiation and execution of power procurement agreements with the applicable utility provider, and the arrangement of project-level senior secured construction financing. This engagement letter (this "Letter") sets forth the terms and conditions of the Firm's engagement by the Client in connection with this matter, and we ask that you review it carefully. If you have any questions regarding the terms described herein, please do not hesitate to contact me directly.

2. Identification of the Client

The client in this engagement is Ironhaven Data Centers LLC, a Delaware limited liability company (EIN: 84-3291057; Virginia State Corporation Commission Entity ID: S7491283). We understand that IHDC is a portfolio company of Ridgeline Capital Partners Fund IV, LP ("Ridgeline Fund IV"), a Delaware limited partnership. Ridgeline Fund IV holds a ninety-two percent (92%) equity interest in IHDC through an intermediate holding entity, RCP Digital Holdings LLC, a Delaware limited liability company. The remaining eight percent (8%) equity interest in IHDC is held by IHDC management through Ironhaven Management Incentive Pool LLC, a Delaware limited liability company.

It is important to note, and the Client hereby acknowledges, that the Firm does not represent Ridgeline Capital Partners Fund IV, LP, Ridgeline Capital Management LLC (the general partner and/or investment manager of Ridgeline Fund IV), RCP Digital Holdings LLC, Ironhaven Management Incentive Pool LLC, or any other affiliated or related entity of the Client, unless the Firm is separately engaged to do so in writing. Our obligations of loyalty, confidentiality, and professional responsibility in this engagement run solely to Ironhaven Data Centers LLC, and not to any parent, affiliate, subsidiary, member, partner, manager, or equity holder of IHDC, except as otherwise expressly provided in this Letter.

Notwithstanding the foregoing, we acknowledge that in the course of this engagement, the Firm may form and provide legal advice with respect to Stonebridge Campus Holdings LLC, a to-be-formed Virginia single-purpose limited liability company that will serve as the project-level borrower entity for the construction financing described in Section 3.7 below. It is anticipated that Stonebridge Campus Holdings LLC will be wholly owned by IHDC. To the extent the Firm forms and advises that entity, such representation shall be considered part of this engagement, and Stonebridge Campus Holdings LLC shall be treated as a client of the Firm for conflict-of-interest purposes and all other purposes under the applicable rules of professional conduct.

3. Scope of Engagement

3.1 Overview. This engagement encompasses all legal workstreams reasonably necessary to effectuate the development, financing, and construction of the Stonebridge Campus. The Stonebridge Campus is to be located at the intersection of Belmont Ridge Road and Stonebridge Boulevard, in unincorporated Loudoun County, Virginia 20148. The Campus will comprise approximately 81.4 acres across two contiguous parcels, as further described in Section 3.2 below, and is designed to deliver approximately 96 megawatts ("MW") of critical IT load capacity across four data center buildings, designated Buildings A through D, each with a designed capacity of approximately 24 MW. The following subsections describe the principal areas in which the Firm will provide legal services. The scope described herein is intended to be comprehensive but not exhaustive; from time to time, additional matters may arise in connection with the Project that fall within the reasonable scope of this engagement, and the Firm will address such matters as part of this engagement unless the parties agree otherwise.

3.2 Land Assemblage

The Firm will represent the Client in connection with the acquisition of the two parcels of land that together comprise the Stonebridge Campus site, including the following:

(a) Stonebridge Parcel. Negotiation, drafting, and closing of the purchase and sale agreement (the "Stonebridge PSA") for the acquisition of approximately 62.0 acres of land identified on the Loudoun County Tax Map as Reference No. /95-4A-1/// (the "Stonebridge Parcel"), to be acquired from Blackthorn Realty Group, Inc., a Virginia corporation ("Blackthorn"). The anticipated purchase price for the Stonebridge Parcel is Fifty-Eight Million Five Hundred Thousand Dollars ($58,500,000).

(b) Meridian Parcel. Negotiation, drafting, and closing of the purchase and sale agreement (the "Meridian PSA") for the acquisition of approximately 19.4 acres of land identified on the Loudoun County Tax Map as Reference No. /95-4A-2/// (the "Meridian Parcel"), to be acquired from Meridian Acres LLC, a Virginia limited liability company ("Meridian Acres"). The anticipated purchase price for the Meridian Parcel is Nineteen Million Four Hundred Thousand Dollars ($19,400,000).

The total anticipated land acquisition cost for the two parcels is approximately Seventy-Seven Million Nine Hundred Thousand Dollars ($77,900,000). In connection with the foregoing acquisitions, the Firm's scope of services will include:

(c) Review and analysis of title commitments issued by Fidelitas Title & Escrow, Inc. (underwritten by Sovereign Title Insurance Company), and the performance of title curative work as necessary, including negotiation of title endorsements, resolution of title exceptions, and the preparation or review of curative instruments.

(d) Review of ALTA/NSPS land title surveys to be prepared by Lumen Ridge Engineering, PLLC, for both the Stonebridge Parcel and the Meridian Parcel, including coordination with the surveyor to address any survey-related exceptions or discrepancies.

(e) Coordination and review of environmental due diligence, including Phase I Environmental Site Assessments and, if recommended, Phase II Environmental Site Assessments, to be conducted by Pendleton Environmental Associates, Inc. The Firm will review the environmental reports and advise the Client regarding any recognized environmental conditions, historical recognized environmental conditions, or controlled recognized environmental conditions identified therein, and their implications for the acquisition and financing of the parcels.

(f) Review of geotechnical reports to be prepared by Brannigan Geotechnical Engineering, LLC, with respect to both parcels, and advice as to any material findings that may affect the development or the allocation of risk in the purchase and sale agreements.

(g) Review and negotiation of escrow agreements governing the deposit and disbursement of earnest money deposits under the Stonebridge PSA and the Meridian PSA, including escrow agreements with Fidelitas Title & Escrow, Inc. or such other escrow agent as the parties may designate.

(h) Preparation of assignment and assumption agreements to facilitate the assignment of the purchase and sale agreements from IHDC to the project-level borrower entity, Stonebridge Campus Holdings LLC, at or prior to closing, as may be required by the construction lender or otherwise directed by the Client.

(i) Preparation and review of all closing documentation, including special warranty deeds, seller affidavits, settlement statements, transfer tax declarations, and all ancillary closing instruments and certificates.

(j) Coordination with Greystone Appraisal Partners, LLC regarding the preparation of appraisals of the Stonebridge Parcel, the Meridian Parcel, and the assembled campus, as required by the construction lender and the Client.

3.3 Entity Formation and Organizational Matters

The Firm will handle the formation and organizational structuring of the project-level borrower entity, including:

(a) Formation of Stonebridge Campus Holdings LLC as a Virginia limited liability company with the Virginia State Corporation Commission, including the preparation and filing of articles of organization and all related formation documentation.

(b) Drafting of the limited liability company operating agreement for Stonebridge Campus Holdings LLC, incorporating single-purpose entity ("SPE") covenants and separateness provisions customarily required by institutional construction lenders, including provisions relating to the maintenance of separate books, records, and bank accounts; restrictions on indebtedness, guarantees, and affiliate transactions; the appointment of an independent manager or independent director; and compliance with other SPE requirements as may be negotiated with the lender.

(c) Preparation of secretary's certificates, incumbency certificates, member consent resolutions authorizing the transactions contemplated by this engagement (including the execution of the purchase and sale agreements, the construction loan documents, the EPC agreement, and the utility agreements), and any other organizational filings or registrations required by the Virginia State Corporation Commission or applicable law.

3.4 Entitlements and Land Use

The Firm will provide advice and coordination in connection with the land use and entitlements process for the Stonebridge Campus, including:

(a) Advice and coordination regarding the Loudoun County zoning modification application ("ZMOD") required to permit data center use on the campus parcels. We understand that the parcels are currently zoned PD-IP (Planned Development – Industrial Park) under the Loudoun County Revised 1993 Zoning Ordinance, and that a zoning modification is required to authorize the proposed data center use, building heights, setbacks, or other development parameters. The expected ZMOD application docket number is ZMOD-2025-0038.

(b) Preparation and review of the ZMOD application narrative and statement of justification, including coordination with the Client's land use consultant, Cornerstone Land Use Consulting, LLC (Alan Mercer, Principal Consultant), and the Firm's local zoning counsel (see subsection (d) below), to ensure that the application materials are comprehensive, persuasive, and consistent with the applicable provisions of the Loudoun County Zoning Ordinance and the Comprehensive Plan.

(c) Development of the proffer negotiation strategy, including the identification of community impact topics (transportation, fiscal impact, noise, visual screening, stormwater, and community benefit contributions), and the drafting of proffer statements for submission to Loudoun County in connection with the ZMOD application.

(d) Coordination with local zoning counsel, Ashcroft & Wynn, P.C. ("A&W"), located at 25 West Market Street, Leesburg, Virginia 20176 (Thomas Ashcroft, Lead Partner), who will serve as counsel of record for the ZMOD application and will appear before the Loudoun County Planning Commission and the Board of Supervisors as necessary. The retention of local counsel is further addressed in Section 7 of this Letter.

(e) Coordination with Cornerstone Land Use Consulting, LLC (Alan Mercer, Principal Consultant), the Client's land use and planning consultant, with respect to site plan submissions, community outreach, and the preparation of transportation impact analyses, fiscal impact studies, and other technical studies required in support of the ZMOD application.

3.5 EPC Contract

The Firm will represent the Client in the negotiation, drafting, and execution of the engineering, procurement, and construction agreement (the "EPC Agreement") for the construction of the Stonebridge Campus, including:

(a) Negotiation, drafting, and execution of the EPC Agreement with Titan-McAllister Construction Group, LLC, a Maryland limited liability company ("Titan-McAllister" or the "Contractor"), as the general contractor for the Stonebridge Campus. The EPC Agreement is anticipated to be structured as a guaranteed maximum price ("GMP") contract with a guaranteed maximum price of approximately Four Hundred Twelve Million Dollars ($412,000,000).

(b) Review and negotiation of the scope of work, technical specifications, division of responsibilities, construction schedule (including interim and substantial completion milestones for each of Buildings A through D), and phasing provisions.

(c) Review and negotiation of insurance requirements under the EPC Agreement, including builder's risk insurance, commercial general liability insurance, professional liability insurance, automobile liability insurance, and umbrella/excess liability insurance, and coordination of insurance requirements with those required under the construction loan documents and the Client's overall insurance program.

(d) Review and negotiation of performance and payment bond requirements, including review of surety bonds to be issued by Great Basin Surety & Insurance Corp. and certificates of insurance to be provided by Pinnacle Indemnity Insurance Co., and confirmation that the form and substance of such bonds and certificates satisfy the requirements of the construction lender.

(e) Review and negotiation of liquidated damages provisions for delay and performance shortfalls, including analysis of the interplay between liquidated damages under the EPC Agreement and any corresponding remedies or obligations under the construction loan documents and utility agreements.

(f) Review and negotiation of change order procedures, retainage provisions, application for payment procedures, dispute resolution mechanisms, and change of control provisions affecting either the Client or the Contractor.

(g) Coordination with Kestrel Infrastructure Advisors, LLC, the Client's owner's representative, with respect to the scope of the owner's representative services agreement, construction monitoring, and the interface between the owner's representative and the Contractor.

3.6 Power Procurement and Utility Agreements

The Firm will represent the Client in connection with the negotiation and execution of power procurement and utility service agreements necessary for the Stonebridge Campus, including:

(a) Negotiation and review of a Large Load Service Agreement ("LLSA") with Vantage Power Cooperative ("VPC") for a contracted demand of 120 megavolt-amperes ("MVA"). The LLSA application has been designated VPC Service Application No. LSA-2025-0091. The Firm will review and negotiate the key commercial terms of the LLSA, including demand charges, energy charges, service reliability provisions, curtailment rights, force majeure, and termination provisions.

(b) Drafting and negotiation of a line extension funding agreement (the "Line Extension Agreement") with VPC, pursuant to which IHDC will fund certain costs associated with the extension and upgrade of electrical infrastructure necessary to serve the Stonebridge Campus. The anticipated contribution by IHDC under the Line Extension Agreement is approximately Eighteen Million Five Hundred Thousand Dollars ($18,500,000). The Firm will negotiate the terms of such contribution, including the structure and timing of payments, refund provisions, ownership of the constructed facilities, and maintenance obligations.

(c) Drafting of a substation easement agreement on the Meridian Parcel in favor of VPC for the construction, operation, and maintenance of a dedicated 230kV/34.5kV electrical substation on a portion of the Meridian Parcel. The Firm will negotiate the terms and conditions of such easement, including the area and location of the easement, access rights, indemnification provisions, restoration obligations, and environmental compliance requirements.

(d) Analysis and advice regarding the Client's backup power strategy, including legal review of generator procurement agreements and any regulatory or permitting requirements associated with the installation and operation of emergency and standby generators at the Stonebridge Campus.

3.7 Project-Level Construction Financing

The Firm will represent the Client and the project-level borrower entity (Stonebridge Campus Holdings LLC) in connection with the negotiation, documentation, and closing of the senior secured construction loan facility for the Stonebridge Campus, including:

(a) The construction loan facility is anticipated to be in a principal amount of approximately Three Hundred Ninety Million Dollars ($390,000,000). The administrative agent and lead arranger for the facility is expected to be Summit National Bank, N.A. ("Summit"), with anticipated co-lenders including Cascade Commercial Lending Corp. and Harborview Trust Company.

(b) The Firm's scope of services will include negotiation and review of the following loan documents (collectively, the "Loan Documents"):

(i) Construction Loan Agreement;

(ii) Promissory Note;

(iii) Deed of Trust, Security Agreement, Fixture Filing, and Assignment of Leases and Rents encumbering the Stonebridge Campus parcels;

(iv) Environmental Indemnity Agreement;

(v) Completion Guaranty (to be executed by IHDC as guarantor);

(vi) Carry/Payment Guaranty (to be executed by IHDC as guarantor);

(vii) Pledge Agreement pledging the membership interests in Stonebridge Campus Holdings LLC;

(viii) Collateral Assignment of EPC Agreement;

(ix) Collateral Assignment of Permits and Entitlements;

(x) Collateral Assignment of Leases (to the extent any pre-leasing is executed prior to the loan closing);

(xi) UCC-1 Financing Statements;

(xii) All related schedules, exhibits, certificates, and ancillary loan documents.

(c) Preparation of the borrower's closing certificate and the legal opinion letter to be delivered to the lenders at closing, including opinions as to due organization, authorization, enforceability, no conflicts, and such other legal opinions as may be customarily required by the lenders and their counsel.

(d) Coordination with lender's counsel, Redmond & Calloway LLP (Victor Redmond, lead partner), regarding the form and substance of the Loan Documents, the closing process, and the satisfaction of conditions precedent to the initial advance.

(e) Analysis and coordination of change of control provisions across the Loan Documents, the EPC Agreement, and the utility agreements to ensure consistency and to identify any potential conflicts or gaps in the change of control framework.

3.8 Equity / Sponsor Documentation

The Firm will assist the Client in connection with the equity and sponsor-level documentation for the Project, including:

(a) Review and negotiation of the equity contribution agreement between Ridgeline Capital Partners Fund IV, LP and IHDC (or between RCP Digital Holdings LLC and IHDC, as applicable) governing the commitment and funding of equity contributions to the Project. The anticipated total equity contribution is approximately Two Hundred Ten Million Dollars ($210,000,000), representing approximately thirty-five percent (35%) of total project costs.

(b) Preparation of side letters, representations, warranties, and covenants for the benefit of the construction lender, confirming the equity commitment and funding obligations and providing such additional assurances as the lender may reasonably require.

(c) Preparation of member consent resolutions of IHDC and its members authorizing the equity contribution and the transactions contemplated by this engagement.

3.9 Tax Matters

The Firm will provide tax advice and coordination in connection with the Project, including:

(a) Analysis of the qualification of the Stonebridge Campus for the Virginia data center sales and use tax exemption under Section 58.1-609.3(18) of the Code of Virginia, including advice on the investment thresholds, new job creation requirements, and certification procedures applicable to the exemption.

(b) Advice on entity structure and federal and state tax elections for the project-level borrower entity, Stonebridge Campus Holdings LLC, including analysis of classification for federal income tax purposes (disregarded entity vs. partnership) and any state-level tax implications.

(c) Coordination regarding the scope and timing of a cost segregation study for the Stonebridge Campus, including identification of assets eligible for accelerated depreciation or bonus depreciation under the Internal Revenue Code.

(d) Analysis of the Loudoun County data center equipment tax assessment methodology, including the classification of data center equipment as business tangible personal property and the applicable tax rates and assessment procedures.

(e) Coordination with the Client's accounting firm, Fielding & Associates, CPAs (Robert Fielding, CPA), regarding tax planning, compliance, and reporting matters as they relate to the Project.

3.10 Insurance. The Firm will review and advise on the insurance program for the Project, including:

(a) Review of the Project insurance program, including builder's risk insurance during the construction phase, evaluation of an Owner-Controlled Insurance Program ("OCIP"), operational property and casualty coverages, business interruption / extra expense coverage, and directors' and officers' ("D&O") insurance for the project-level entity and its managers.

(b) Cross-referencing of insurance requirements under the EPC Agreement and the Loan Documents to ensure that the Client's insurance program satisfies all contractual obligations and that there are no gaps or inconsistencies in coverage.

(c) Coordination with the Client's insurance broker, Northgate Insurance Brokerage, LLC (William Keane, Account Executive), regarding the placement and terms of the applicable insurance policies.

3.11 Easements and Reciprocal Agreements

The Firm will draft and negotiate the easement and reciprocal agreement framework for the multi-parcel Stonebridge Campus, including:

(a) Drafting and negotiation of cross-access and utility easement agreements between and among the Stonebridge Parcel and the Meridian Parcel, including vehicular and pedestrian access easements, underground and above-ground utility easements (for electric, water, sewer, telecommunications, and fiber), and temporary construction easements as needed during the construction phase.

(b) Stormwater management facility easement and maintenance agreements, including the grant of perpetual easements for the construction, operation, and maintenance of stormwater management facilities serving the campus, and the establishment of maintenance obligations, cost-sharing mechanisms, and reporting requirements as may be required by Loudoun County or the Virginia Department of Environmental Quality.

(c) Analysis of the overall easement and declaration structure for the multi-parcel campus, including evaluation of whether a declaration of covenants, conditions, and restrictions ("CC&Rs") or a reciprocal easement agreement ("REA") is appropriate to govern the ongoing operation, maintenance, and shared use of common infrastructure across the campus.

3.12 Closing and Post-Closing

The Firm will manage the closing and post-closing processes for the transactions described herein, including:

(a) Preparation and maintenance of master closing checklists for the land acquisitions (Stonebridge PSA closing and Meridian PSA closing) and the construction loan closing, including tracking of all conditions precedent, deliverables, and responsible parties.

(b) Pre-closing bring-down due diligence, including verification that all representations and warranties remain true and correct as of the applicable closing dates, confirmation of the absence of material adverse changes, and updates to title commitments, surveys, and UCC lien searches.

(c) Post-closing obligations tracking and compliance monitoring, including monitoring of post-closing deliverables (such as recorded documents, title policy issuance, UCC continuation filings, organizational and corporate maintenance filings, and any post-closing purchase price adjustments) and preparation of periodic post-closing compliance memoranda for the Client.

(d) Assembly and distribution of closing binders (physical and/or electronic) containing executed copies of all transaction documents.

4. Responsible Attorneys

The following attorneys will be primarily responsible for the Firm's work on this engagement:

Responsible Partner: Douglas Fairchild, Partner, Real Estate Practice Group, Calderwood & Harkness LLP. Mr. Fairchild will serve as the primary relationship partner for this engagement and as the primary point of contact for the Client on all significant matters relating to the Project.

Billing Partner: Angela Fontaine, Partner, Real Estate Practice Group, Calderwood & Harkness LLP. Ms. Fontaine will be responsible for billing, invoicing, and budget management for the engagement.

Lead Associate: Cynthia Ho, Associate, Real Estate Practice Group, Calderwood & Harkness LLP. Ms. Ho will handle day-to-day workstream management, drafting, and negotiations across all workstreams described in Section 3 of this Letter.

Working Associate: Grace Nakamura, Associate, Real Estate Practice Group, Calderwood & Harkness LLP. Ms. Nakamura will serve as the supporting associate for due diligence, document preparation, research, and other tasks as assigned.

Tax Specialist: Sylvia Hartwell, Partner, Tax Practice Group, Calderwood & Harkness LLP. Ms. Hartwell will advise on all tax-related matters described in Section 3.9 of this Letter, including the Virginia data center sales and use tax exemption analysis, entity structure and tax elections, cost segregation coordination, and Loudoun County equipment tax assessment matters.

Additional attorneys, paralegals, and staff may be assigned to the engagement as needed based on the volume and complexity of the work. The Firm will provide notice to the Client of any such additional assignments. Day-to-day communications regarding the Project may be directed to Mr. Fairchild or, for operational and drafting matters, to Ms. Ho, who will ensure that matters are escalated to Mr. Fairchild as appropriate.

5. Client Contacts

The following individuals are designated as the Client's primary contacts for this engagement:

Marcus Thorne, Chief Executive Officer, Ironhaven Data Centers LLC — overall project authority and strategic decisions.

Priya Dasgupta, Chief Financial Officer, Ironhaven Data Centers LLC — financial matters, construction loan negotiations, project budget, and tax coordination.

Leonard Castellano, Executive Vice President of Development, Ironhaven Data Centers LLC — development operations, EPC Agreement negotiations, entitlements and land use, and construction matters.

Julian Hargrove, Managing Partner, Ridgeline Capital Management LLC — equity sponsor communications, as directed by IHDC. For the avoidance of doubt, the Firm's communications with Mr. Hargrove will be at the direction and authorization of IHDC and do not constitute an attorney-client relationship between the Firm and Mr. Hargrove or Ridgeline Capital Management LLC.

The Client may modify its designated contacts at any time by written notice to the Firm.

6. Fees and Billing Arrangements

6.1 Hourly Rates

Fees for the Firm's legal services in connection with this engagement will be based on the Firm's standard hourly rates for the attorneys and paralegals working on the matter. Rates vary by the seniority, experience, and practice area of the individual timekeepers. A schedule of the Firm's current hourly rates for the timekeepers anticipated to work on this engagement is attached hereto as Exhibit A (the "Rate Schedule"). The rates set forth in the Rate Schedule are subject to periodic adjustment, which typically occurs on an annual basis effective January 1 of each year. The Firm will provide the Client with advance written notice of any rate adjustment not less than thirty (30) days prior to the effective date of such adjustment.

6.2 Billing and Payment

Angela Fontaine will serve as the billing partner for this engagement and will be responsible for the preparation and issuance of all invoices. The Firm will render monthly invoices to the Client, which will detail the time entries of each attorney and paralegal who worked on the matter during the billing period, including a description of the tasks performed and the time spent on each task, as well as an itemization of all disbursements and out-of-pocket expenses incurred during the period. Payment of each invoice is due within thirty (30) days of the invoice date. All invoices will be directed to Priya Dasgupta, Chief Financial Officer, at the Client's offices at 44680 Prentice Drive, Suite 200, Ashburn, Virginia 20147, or to such other address or email address as the Client may designate from time to time. If the Client disputes any portion of an invoice, the Client agrees to notify the Firm in writing within fifteen (15) days of receipt, and the parties will work in good faith to resolve any such dispute promptly. Undisputed amounts shall remain due and payable within the thirty (30) day payment period regardless of any dispute as to other amounts.

6.3 Disbursements and Expenses

In addition to professional fees, the Client will be responsible for the reimbursement of all reasonable out-of-pocket expenses and disbursements incurred by the Firm in connection with this engagement. Such disbursements may include, without limitation, filing fees (including fees payable to the Virginia State Corporation Commission and the Loudoun County Clerk's Office for the recording of deeds, deeds of trust, and other instruments), recording fees, courier and delivery charges, travel expenses (including airfare, ground transportation, lodging, and meals for travel reasonably necessary in connection with the engagement), title search and examination costs, photocopying and printing costs, and third-party vendor costs advanced by the Firm on behalf of the Client. Filing fees, recording fees, and other governmental charges will be passed through to the Client at cost, without markup. Travel expenses will be incurred in accordance with the Firm's standard travel policy, and the Firm will exercise reasonable judgment in incurring such expenses.

6.4 Retainer. No retainer deposit is required at the commencement of this engagement. The Firm reserves the right to request a retainer or advance deposit in the future if, in the Firm's reasonable judgment, the outstanding balance of unpaid invoices or the anticipated volume of work warrants such a request.

6.5 Budget Estimate

A preliminary budget estimate for the engagement, broken down by workstream, will be provided to the Client under separate cover in the Staffing Plan and Budget Estimate Memorandum dated March 14, 2025. The Client acknowledges that budget estimates are non-binding projections provided for planning purposes only and are subject to revision based on the actual scope, complexity, and duration of the matters as they develop. Material changes in scope, the involvement of additional parties, unforeseen complications in due diligence or negotiations, or protracted entitlement proceedings may result in fees that exceed the initial budget estimate. The Firm will endeavor to keep the Client informed of any material developments that are likely to result in a significant deviation from the budget estimate and will work with the Client to manage costs effectively.

7. Retention of Local Counsel and Other Professionals

The Firm intends to retain Ashcroft & Wynn, P.C. ("A&W"), located at 25 West Market Street, Leesburg, Virginia 20176 (Thomas Ashcroft, Lead Partner), as local zoning counsel in connection with the ZMOD application, proffer negotiations, appearances before the Loudoun County Planning Commission and Board of Supervisors, and related Loudoun County land use matters. A&W has significant experience with data center entitlement matters in Loudoun County and is well-positioned to serve as counsel of record before the applicable Loudoun County boards and commissions. The fees and expenses of local counsel will be the responsibility of the Client (IHDC) and may, at the Client's election, be billed through C&H (in which case such fees will appear as a disbursement on the Firm's invoices) or directly by A&W to the Client. The Firm will coordinate the work of A&W with the other workstreams of the engagement to ensure consistency and efficiency.

In addition, the Firm will coordinate with, but does not serve as counsel to, the various third-party consultants and advisors engaged by IHDC in connection with the Project. These include, but are not limited to, the following:

• Cornerstone Land Use Consulting, LLC (Alan Mercer, Principal Consultant) — land use and planning consulting

• Pendleton Environmental Associates, Inc. — environmental site assessments

• Brannigan Geotechnical Engineering, LLC — geotechnical investigations

• Kestrel Infrastructure Advisors, LLC — owner's representative services

• Lumen Ridge Engineering, PLLC — surveying

• Greystone Appraisal Partners, LLC — appraisal services

• Northgate Insurance Brokerage, LLC (William Keane, Account Executive) — insurance brokerage

• Fielding & Associates, CPAs (Robert Fielding, CPA) — accounting and tax advisory

The Firm does not represent any of the foregoing consultants or advisors, and the engagement of such parties is the sole responsibility of the Client. The Firm will review and coordinate with the work product of these consultants as described in Section 3 of this Letter to the extent necessary for the legal workstreams within the Firm's scope.

8. Conflicts of Interest

The Firm has conducted a conflict of interest check as of March 12, 2025, in accordance with the Firm's standard procedures and the requirements of the applicable rules of professional conduct. Based on that conflict check, the Firm has not identified any conflicts of interest that would prevent the Firm from undertaking this engagement. The conflict check encompassed all known parties to the transactions contemplated by this engagement, including Ironhaven Data Centers LLC, Ridgeline Capital Partners Fund IV, LP, RCP Digital Holdings LLC, Blackthorn Realty Group, Inc., Meridian Acres LLC, Titan-McAllister Construction Group, LLC, Summit National Bank, N.A., Cascade Commercial Lending Corp., Harborview Trust Company, and Vantage Power Cooperative.

The Client acknowledges that Calderwood & Harkness LLP is a large, multi-office law firm with attorneys practicing in numerous jurisdictions and across a wide range of practice areas. In the ordinary course of its practice, the Firm may from time to time represent other clients whose interests may be adverse to those of IHDC in matters that are wholly unrelated to this engagement and to the Stonebridge Campus development. By executing this Letter, the Client consents to the Firm's representation of other clients in matters unrelated to this engagement, provided that such representation does not involve the use of confidential information obtained from IHDC and does not create a conflict that would materially impair the Firm's ability to represent IHDC in this engagement. This consent does not extend to any matter in which the Firm's representation of another client would be directly adverse to IHDC in the same transaction, dispute, or proceeding.

Should a conflict of interest arise during the course of this engagement, the Firm will promptly notify the Client and take all appropriate steps in accordance with the applicable rules of professional conduct, which may include seeking informed consent from the affected parties or, if consent cannot be obtained, withdrawing from the representation of one or more affected clients as required.

9. Confidentiality

The Firm will maintain the confidentiality of all information provided by the Client, or obtained by the Firm on behalf of the Client, in connection with this engagement, in accordance with the Firm's professional obligations and the applicable rules of professional conduct. The Firm will not disclose such confidential information to any third party without the Client's prior consent, except as required by law, court order, or the Firm's professional obligations, or as reasonably necessary for the performance of the Firm's services under this engagement.

Confidential information may be shared within the Firm on a need-to-know basis among attorneys, paralegals, and staff working on this engagement. Confidential information may also be shared with local counsel (Ashcroft & Wynn, P.C.) to the extent necessary for A&W to perform its role in the engagement, subject to A&W's own obligations of confidentiality. The Firm will take reasonable precautions to safeguard the Client's confidential information, including the use of secure electronic communication and document management systems.

10. Document Retention

Upon the conclusion of this engagement, the Firm will retain the Client's files and documents in accordance with the Firm's standard document retention policy, a copy of which will be provided to the Client upon request. The Firm's current policy provides for the retention of closed matter files for a period of ten (10) years following the conclusion of the engagement, after which the files may be destroyed in the Firm's discretion upon thirty (30) days' prior written notice to the Client, unless the Client requests return or further retention of the files. The Client may request the return of original documents at any time during or after the engagement, and the Firm will promptly comply with any such request, subject to the Firm's right to retain copies for its records and to comply with its professional obligations.

11. Termination

Either party may terminate this engagement at any time upon written notice to the other party. Upon termination by either party, the Client will remain responsible for the payment of all fees, disbursements, and expenses incurred through the date of termination, including any fees for time spent by the Firm in connection with the orderly transition of the matter to successor counsel. Upon termination, the Firm will cooperate fully in the orderly transition of the matter, including the prompt delivery of all files, documents, and work product to the Client or to successor counsel as directed by the Client, subject to the satisfaction of all outstanding financial obligations of the Client to the Firm. The Firm's obligation to provide cooperation in connection with any such transition shall survive the termination of this engagement.

12. Governing Law

This engagement letter and the terms and conditions set forth herein shall be governed by and construed in accordance with the laws of the Commonwealth of Virginia, without regard to its conflict of laws principles.

13. Limitations on Scope

The scope of this engagement is as described in Section 3 of this Letter. For the avoidance of doubt, the following matters are expressly excluded from the scope of this engagement and will not be performed by the Firm unless separately agreed to in a written amendment to this Letter or in a separate engagement letter:

(a) Representation of IHDC or any of its affiliates in tenant leasing negotiations for the Stonebridge Campus, including the negotiation and drafting of data center lease, license, or colocation agreements;

(b) Securities or capital markets matters, including any offering of equity or debt securities by IHDC, Ridgeline Fund IV, or any affiliated entity;

(c) Labor and employment matters, including employment agreements, benefit plans, wage and hour compliance, or employment-related disputes;

(d) Litigation, arbitration, or other dispute resolution proceedings of any nature, unless separately agreed to in writing; and

(e) PJM Interconnection, Federal Energy Regulatory Commission ("FERC"), or other energy regulatory matters. To the extent that the Project requires analysis of or compliance with PJM interconnection requirements, FERC regulations, or other energy regulatory matters, the Client should retain specialized energy regulatory counsel with expertise in those areas.

The Firm will endeavor to alert the Client to any issues that the Firm identifies in the course of this engagement that may fall outside the scope described herein but that may require the Client's attention or the engagement of additional counsel.

14. Agreement and Acceptance

We are delighted to have the opportunity to represent Ironhaven Data Centers LLC in connection with the Stonebridge Data Center Campus development, and we look forward to working closely with you and your team throughout the Project. Please indicate your acceptance of the terms and conditions set forth in this Letter by countersigning where indicated below and returning one signed copy to us by email or U.S. mail. This Letter, together with Exhibit A attached hereto, constitutes the entire agreement between the parties with respect to the subject matter hereof and supersedes all prior discussions, understandings, and agreements, whether written or oral, relating to the Firm's engagement by the Client in connection with the Project.

If you have any questions regarding any of the terms of this Letter, please do not hesitate to contact me at (212) 554-7100 or dfairchild@calderwoodharkness.com.

Very truly yours,

CALDERWOOD & HARKNESS LLP

By: ________

Name: Douglas Fairchild

Title: Partner

Calderwood & Harkness LLP 425 Lexington Avenue New York, NY 10017 Telephone: (212) 554-7100

Email: dfairchild@calderwoodharkness.com

Additional Office: 1900 K Street NW, Suite 800 Washington, DC 20006 Telephone: (202) 661-4200

ACKNOWLEDGMENT AND ACCEPTANCE

The undersigned, on behalf of Ironhaven Data Centers LLC, hereby acknowledges receipt of the foregoing Engagement Letter dated March 12, 2025, from Calderwood & Harkness LLP, and agrees to the terms and conditions set forth therein, including but not limited to the scope of engagement, fee arrangements, conflict of interest provisions, and limitations on scope described herein.

IRONHAVEN DATA CENTERS LLC

By: ________

Name: Marcus Thorne

Title: Chief Executive Officer

Date: ________

Enclosures:

Exhibit A: Current Hourly Rate Schedule

cc:

Priya Dasgupta, Chief Financial Officer, Ironhaven Data Centers LLC Leonard Castellano, Executive Vice President of Development, Ironhaven Data Centers LLC Angela Fontaine, Partner, Calderwood & Harkness LLP Cynthia Ho, Associate, Calderwood & Harkness LLP

CONFIDENTIAL — ATTORNEY-CLIENT PRIVILEGED

CALDERWOOD & HARKNESS LLP Attorneys at Law
425 Lexington Avenue New York, NY 10017
Telephone: (212) 554-7000 Facsimile: (212) 554-7001 www.calderwoodharkness.com
March 12, 2025
VIA EMAIL AND U.S. MAIL
Mr. Marcus Thorne Chief Executive Officer Ironhaven Data Centers LLC 44680 Prentice Drive, Suite 200 Ashburn, VA 20147
Re: Engagement of Calderwood & Harkness LLP — Stonebridge Data Center Campus Development Matter No. 1043-00002
Dear Mr. Thorne:
1. Introduction and Engagement Confirmation
Calderwood & Harkness LLP ("C&H" or the "Firm") is pleased to confirm its engagement by Ironhaven Data Centers LLC ("IHDC," "Ironhaven," or the "Client"), a Delaware limited liability company headquartered in Ashburn, Virginia, to represent the Client in connection with the development of a ground-up data center campus known as the Stonebridge Data Center Campus (the "Stonebridge Campus" or the "Project"), to be located in Loudoun County, Virginia. This engagement is effective as of March 12, 2025.
As we have discussed, the Project is a large-scale, multi-building data center development with a total anticipated project budget of approximately Six Hundred Million Dollars ($600,000,000). The Project involves a number of complex and interrelated legal workstreams, including but not limited to land assemblage from multiple sellers, entitlements and permitting through Loudoun County, the negotiation and execution of an engineering, procurement, and construction ("EPC") contract, the negotiation and execution of power procurement agreements with the applicable utility provider, and the arrangement of project-level senior secured construction financing. This engagement letter (this "Letter") sets forth the terms and conditions of the Firm's engagement by the Client in connection with this matter, and we ask that you review it carefully. If you have any questions regarding the terms described herein, please do not hesitate to contact me directly.
2. Identification of the Client
The client in this engagement is Ironhaven Data Centers LLC, a Delaware limited liability company (EIN: 84-3291057; Virginia State Corporation Commission Entity ID: S7491283). We understand that IHDC is a portfolio company of Ridgeline Capital Partners Fund IV, LP ("Ridgeline Fund IV"), a Delaware limited partnership. Ridgeline Fund IV holds a ninety-two percent (92%) equity interest in IHDC through an intermediate holding entity, RCP Digital Holdings LLC, a Delaware limited liability company. The remaining eight percent (8%) equity interest in IHDC is held by IHDC management through Ironhaven Management Incentive Pool LLC, a Delaware limited liability company.
It is important to note, and the Client hereby acknowledges, that the Firm does not represent Ridgeline Capital Partners Fund IV, LP, Ridgeline Capital Management LLC (the general partner and/or investment manager of Ridgeline Fund IV), RCP Digital Holdings LLC, Ironhaven Management Incentive Pool LLC, or any other affiliated or related entity of the Client, unless the Firm is separately engaged to do so in writing. Our obligations of loyalty, confidentiality, and professional responsibility in this engagement run solely to Ironhaven Data Centers LLC, and not to any parent, affiliate, subsidiary, member, partner, manager, or equity holder of IHDC, except as otherwise expressly provided in this Letter.
Notwithstanding the foregoing, we acknowledge that in the course of this engagement, the Firm may form and provide legal advice with respect to Stonebridge Campus Holdings LLC, a to-be-formed Virginia single-purpose limited liability company that will serve as the project-level borrower entity for the construction financing described in Section 3.7 below. It is anticipated that Stonebridge Campus Holdings LLC will be wholly owned by IHDC. To the extent the Firm forms and advises that entity, such representation shall be considered part of this engagement, and Stonebridge Campus Holdings LLC shall be treated as a client of the Firm for conflict-of-interest purposes and all other purposes under the applicable rules of professional conduct.
3. Scope of Engagement
3.1 Overview.  This engagement encompasses all legal workstreams reasonably necessary to effectuate the development, financing, and construction of the Stonebridge Campus. The Stonebridge Campus is to be located at the intersection of Belmont Ridge Road and Stonebridge Boulevard, in unincorporated Loudoun County, Virginia 20148. The Campus will comprise approximately 81.4 acres across two contiguous parcels, as further described in Section 3.2 below, and is designed to deliver approximately 96 megawatts ("MW") of critical IT load capacity across four data center buildings, designated Buildings A through D, each with a designed capacity of approximately 24 MW. The following subsections describe the principal areas in which the Firm will provide legal services. The scope described herein is intended to be comprehensive but not exhaustive; from time to time, additional matters may arise in connection with the Project that fall within the reasonable scope of this engagement, and the Firm will address such matters as part of this engagement unless the parties agree otherwise.
3.2 Land Assemblage
The Firm will represent the Client in connection with the acquisition of the two parcels of land that together comprise the Stonebridge Campus site, including the following:
(a) Stonebridge Parcel. Negotiation, drafting, and closing of the purchase and sale agreement (the "Stonebridge PSA") for the acquisition of approximately 62.0 acres of land identified on the Loudoun County Tax Map as Reference No. /95-4A-1/// (the "Stonebridge Parcel"), to be acquired from Blackthorn Realty Group, Inc., a Virginia corporation ("Blackthorn"). The anticipated purchase price for the Stonebridge Parcel is Fifty-Eight Million Five Hundred Thousand Dollars ($58,500,000).
(b) Meridian Parcel. Negotiation, drafting, and closing of the purchase and sale agreement (the "Meridian PSA") for the acquisition of approximately 19.4 acres of land identified on the Loudoun County Tax Map as Reference No. /95-4A-2/// (the "Meridian Parcel"), to be acquired from Meridian Acres LLC, a Virginia limited liability company ("Meridian Acres"). The anticipated purchase price for the Meridian Parcel is Nineteen Million Four Hundred Thousand Dollars ($19,400,000).
The total anticipated land acquisition cost for the two parcels is approximately Seventy-Seven Million Nine Hundred Thousand Dollars ($77,900,000). In connection with the foregoing acquisitions, the Firm's scope of services will include:
(c) Review and analysis of title commitments issued by Fidelitas Title & Escrow, Inc. (underwritten by Sovereign Title Insurance Company), and the performance of title curative work as necessary, including negotiation of title endorsements, resolution of title exceptions, and the preparation or review of curative instruments.
(d) Review of ALTA/NSPS land title surveys to be prepared by Lumen Ridge Engineering, PLLC, for both the Stonebridge Parcel and the Meridian Parcel, including coordination with the surveyor to address any survey-related exceptions or discrepancies.
(e) Coordination and review of environmental due diligence, including Phase I Environmental Site Assessments and, if recommended, Phase II Environmental Site Assessments, to be conducted by Pendleton Environmental Associates, Inc. The Firm will review the environmental reports and advise the Client regarding any recognized environmental conditions, historical recognized environmental conditions, or controlled recognized environmental conditions identified therein, and their implications for the acquisition and financing of the parcels.
(f) Review of geotechnical reports to be prepared by Brannigan Geotechnical Engineering, LLC, with respect to both parcels, and advice as to any material findings that may affect the development or the allocation of risk in the purchase and sale agreements.
(g) Review and negotiation of escrow agreements governing the deposit and disbursement of earnest money deposits under the Stonebridge PSA and the Meridian PSA, including escrow agreements with Fidelitas Title & Escrow, Inc. or such other escrow agent as the parties may designate.
(h) Preparation of assignment and assumption agreements to facilitate the assignment of the purchase and sale agreements from IHDC to the project-level borrower entity, Stonebridge Campus Holdings LLC, at or prior to closing, as may be required by the construction lender or otherwise directed by the Client.
(i) Preparation and review of all closing documentation, including special warranty deeds, seller affidavits, settlement statements, transfer tax declarations, and all ancillary closing instruments and certificates.
(j) Coordination with Greystone Appraisal Partners, LLC regarding the preparation of appraisals of the Stonebridge Parcel, the Meridian Parcel, and the assembled campus, as required by the construction lender and the Client.
3.3 Entity Formation and Organizational Matters
The Firm will handle the formation and organizational structuring of the project-level borrower entity, including:
(a) Formation of Stonebridge Campus Holdings LLC as a Virginia limited liability company with the Virginia State Corporation Commission, including the preparation and filing of articles of organization and all related formation documentation.
(b) Drafting of the limited liability company operating agreement for Stonebridge Campus Holdings LLC, incorporating single-purpose entity ("SPE") covenants and separateness provisions customarily required by institutional construction lenders, including provisions relating to the maintenance of separate books, records, and bank accounts; restrictions on indebtedness, guarantees, and affiliate transactions; the appointment of an independent manager or independent director; and compliance with other SPE requirements as may be negotiated with the lender.
(c) Preparation of secretary's certificates, incumbency certificates, member consent resolutions authorizing the transactions contemplated by this engagement (including the execution of the purchase and sale agreements, the construction loan documents, the EPC agreement, and the utility agreements), and any other organizational filings or registrations required by the Virginia State Corporation Commission or applicable law.
3.4 Entitlements and Land Use
The Firm will provide advice and coordination in connection with the land use and entitlements process for the Stonebridge Campus, including:
(a) Advice and coordination regarding the Loudoun County zoning modification application ("ZMOD") required to permit data center use on the campus parcels. We understand that the parcels are currently zoned PD-IP (Planned Development – Industrial Park) under the Loudoun County Revised 1993 Zoning Ordinance, and that a zoning modification is required to authorize the proposed data center use, building heights, setbacks, or other development parameters. The expected ZMOD application docket number is ZMOD-2025-0038.
(b) Preparation and review of the ZMOD application narrative and statement of justification, including coordination with the Client's land use consultant, Cornerstone Land Use Consulting, LLC (Alan Mercer, Principal Consultant), and the Firm's local zoning counsel (see subsection (d) below), to ensure that the application materials are comprehensive, persuasive, and consistent with the applicable provisions of the Loudoun County Zoning Ordinance and the Comprehensive Plan.
(c) Development of the proffer negotiation strategy, including the identification of community impact topics (transportation, fiscal impact, noise, visual screening, stormwater, and community benefit contributions), and the drafting of proffer statements for submission to Loudoun County in connection with the ZMOD application.
(d) Coordination with local zoning counsel, Ashcroft & Wynn, P.C. ("A&W"), located at 25 West Market Street, Leesburg, Virginia 20176 (Thomas Ashcroft, Lead Partner), who will serve as counsel of record for the ZMOD application and will appear before the Loudoun County Planning Commission and the Board of Supervisors as necessary. The retention of local counsel is further addressed in Section 7 of this Letter.
(e) Coordination with Cornerstone Land Use Consulting, LLC (Alan Mercer, Principal Consultant), the Client's land use and planning consultant, with respect to site plan submissions, community outreach, and the preparation of transportation impact analyses, fiscal impact studies, and other technical studies required in support of the ZMOD application.
3.5 EPC Contract
The Firm will represent the Client in the negotiation, drafting, and execution of the engineering, procurement, and construction agreement (the "EPC Agreement") for the construction of the Stonebridge Campus, including:
(a) Negotiation, drafting, and execution of the EPC Agreement with Titan-McAllister Construction Group, LLC, a Maryland limited liability company ("Titan-McAllister" or the "Contractor"), as the general contractor for the Stonebridge Campus. The EPC Agreement is anticipated to be structured as a guaranteed maximum price ("GMP") contract with a guaranteed maximum price of approximately Four Hundred Twelve Million Dollars ($412,000,000).
(b) Review and negotiation of the scope of work, technical specifications, division of responsibilities, construction schedule (including interim and substantial completion milestones for each of Buildings A through D), and phasing provisions.
(c) Review and negotiation of insurance requirements under the EPC Agreement, including builder's risk insurance, commercial general liability insurance, professional liability insurance, automobile liability insurance, and umbrella/excess liability insurance, and coordination of insurance requirements with those required under the construction loan documents and the Client's overall insurance program.
(d) Review and negotiation of performance and payment bond requirements, including review of surety bonds to be issued by Great Basin Surety & Insurance Corp. and certificates of insurance to be provided by Pinnacle Indemnity Insurance Co., and confirmation that the form and substance of such bonds and certificates satisfy the requirements of the construction lender.
(e) Review and negotiation of liquidated damages provisions for delay and performance shortfalls, including analysis of the interplay between liquidated damages under the EPC Agreement and any corresponding remedies or obligations under the construction loan documents and utility agreements.
(f) Review and negotiation of change order procedures, retainage provisions, application for payment procedures, dispute resolution mechanisms, and change of control provisions affecting either the Client or the Contractor.
(g) Coordination with Kestrel Infrastructure Advisors, LLC, the Client's owner's representative, with respect to the scope of the owner's representative services agreement, construction monitoring, and the interface between the owner's representative and the Contractor.
3.6 Power Procurement and Utility Agreements
The Firm will represent the Client in connection with the negotiation and execution of power procurement and utility service agreements necessary for the Stonebridge Campus, including:
(a) Negotiation and review of a Large Load Service Agreement ("LLSA") with Vantage Power Cooperative ("VPC") for a contracted demand of 120 megavolt-amperes ("MVA"). The LLSA application has been designated VPC Service Application No. LSA-2025-0091. The Firm will review and negotiate the key commercial terms of the LLSA, including demand charges, energy charges, service reliability provisions, curtailment rights, force majeure, and termination provisions.
(b) Drafting and negotiation of a line extension funding agreement (the "Line Extension Agreement") with VPC, pursuant to which IHDC will fund certain costs associated with the extension and upgrade of electrical infrastructure necessary to serve the Stonebridge Campus. The anticipated contribution by IHDC under the Line Extension Agreement is approximately Eighteen Million Five Hundred Thousand Dollars ($18,500,000). The Firm will negotiate the terms of such contribution, including the structure and timing of payments, refund provisions, ownership of the constructed facilities, and maintenance obligations.
(c) Drafting of a substation easement agreement on the Meridian Parcel in favor of VPC for the construction, operation, and maintenance of a dedicated 230kV/34.5kV electrical substation on a portion of the Meridian Parcel. The Firm will negotiate the terms and conditions of such easement, including the area and location of the easement, access rights, indemnification provisions, restoration obligations, and environmental compliance requirements.
(d) Analysis and advice regarding the Client's backup power strategy, including legal review of generator procurement agreements and any regulatory or permitting requirements associated with the installation and operation of emergency and standby generators at the Stonebridge Campus.
3.7 Project-Level Construction Financing
The Firm will represent the Client and the project-level borrower entity (Stonebridge Campus Holdings LLC) in connection with the negotiation, documentation, and closing of the senior secured construction loan facility for the Stonebridge Campus, including:
(a) The construction loan facility is anticipated to be in a principal amount of approximately Three Hundred Ninety Million Dollars ($390,000,000). The administrative agent and lead arranger for the facility is expected to be Summit National Bank, N.A. ("Summit"), with anticipated co-lenders including Cascade Commercial Lending Corp. and Harborview Trust Company.
(b) The Firm's scope of services will include negotiation and review of the following loan documents (collectively, the "Loan Documents"):
(i) Construction Loan Agreement;
(ii) Promissory Note;
(iii) Deed of Trust, Security Agreement, Fixture Filing, and Assignment of Leases and Rents encumbering the Stonebridge Campus parcels;
(iv) Environmental Indemnity Agreement;
(v) Completion Guaranty (to be executed by IHDC as guarantor);
(vi) Carry/Payment Guaranty (to be executed by IHDC as guarantor);
(vii) Pledge Agreement pledging the membership interests in Stonebridge Campus Holdings LLC;
(viii) Collateral Assignment of EPC Agreement;
(ix) Collateral Assignment of Permits and Entitlements;
(x) Collateral Assignment of Leases (to the extent any pre-leasing is executed prior to the loan closing);
(xi) UCC-1 Financing Statements;
(xii) All related schedules, exhibits, certificates, and ancillary loan documents.
(c) Preparation of the borrower's closing certificate and the legal opinion letter to be delivered to the lenders at closing, including opinions as to due organization, authorization, enforceability, no conflicts, and such other legal opinions as may be customarily required by the lenders and their counsel.
(d) Coordination with lender's counsel, Redmond & Calloway LLP (Victor Redmond, lead partner), regarding the form and substance of the Loan Documents, the closing process, and the satisfaction of conditions precedent to the initial advance.
(e) Analysis and coordination of change of control provisions across the Loan Documents, the EPC Agreement, and the utility agreements to ensure consistency and to identify any potential conflicts or gaps in the change of control framework.
3.8 Equity / Sponsor Documentation
The Firm will assist the Client in connection with the equity and sponsor-level documentation for the Project, including:
(a) Review and negotiation of the equity contribution agreement between Ridgeline Capital Partners Fund IV, LP and IHDC (or between RCP Digital Holdings LLC and IHDC, as applicable) governing the commitment and funding of equity contributions to the Project. The anticipated total equity contribution is approximately Two Hundred Ten Million Dollars ($210,000,000), representing approximately thirty-five percent (35%) of total project costs.
(b) Preparation of side letters, representations, warranties, and covenants for the benefit of the construction lender, confirming the equity commitment and funding obligations and providing such additional assurances as the lender may reasonably require.
(c) Preparation of member consent resolutions of IHDC and its members authorizing the equity contribution and the transactions contemplated by this engagement.
3.9 Tax Matters
The Firm will provide tax advice and coordination in connection with the Project, including:
(a) Analysis of the qualification of the Stonebridge Campus for the Virginia data center sales and use tax exemption under Section 58.1-609.3(18) of the Code of Virginia, including advice on the investment thresholds, new job creation requirements, and certification procedures applicable to the exemption.
(b) Advice on entity structure and federal and state tax elections for the project-level borrower entity, Stonebridge Campus Holdings LLC, including analysis of classification for federal income tax purposes (disregarded entity vs. partnership) and any state-level tax implications.
(c) Coordination regarding the scope and timing of a cost segregation study for the Stonebridge Campus, including identification of assets eligible for accelerated depreciation or bonus depreciation under the Internal Revenue Code.
(d) Analysis of the Loudoun County data center equipment tax assessment methodology, including the classification of data center equipment as business tangible personal property and the applicable tax rates and assessment procedures.
(e) Coordination with the Client's accounting firm, Fielding & Associates, CPAs (Robert Fielding, CPA), regarding tax planning, compliance, and reporting matters as they relate to the Project.
3.10 Insurance.  The Firm will review and advise on the insurance program for the Project, including:
(a) Review of the Project insurance program, including builder's risk insurance during the construction phase, evaluation of an Owner-Controlled Insurance Program ("OCIP"), operational property and casualty coverages, business interruption / extra expense coverage, and directors' and officers' ("D&O") insurance for the project-level entity and its managers.
(b) Cross-referencing of insurance requirements under the EPC Agreement and the Loan Documents to ensure that the Client's insurance program satisfies all contractual obligations and that there are no gaps or inconsistencies in coverage.
(c) Coordination with the Client's insurance broker, Northgate Insurance Brokerage, LLC (William Keane, Account Executive), regarding the placement and terms of the applicable insurance policies.
3.11 Easements and Reciprocal Agreements
The Firm will draft and negotiate the easement and reciprocal agreement framework for the multi-parcel Stonebridge Campus, including:
(a) Drafting and negotiation of cross-access and utility easement agreements between and among the Stonebridge Parcel and the Meridian Parcel, including vehicular and pedestrian access easements, underground and above-ground utility easements (for electric, water, sewer, telecommunications, and fiber), and temporary construction easements as needed during the construction phase.
(b) Stormwater management facility easement and maintenance agreements, including the grant of perpetual easements for the construction, operation, and maintenance of stormwater management facilities serving the campus, and the establishment of maintenance obligations, cost-sharing mechanisms, and reporting requirements as may be required by Loudoun County or the Virginia Department of Environmental Quality.
(c) Analysis of the overall easement and declaration structure for the multi-parcel campus, including evaluation of whether a declaration of covenants, conditions, and restrictions ("CC&Rs") or a reciprocal easement agreement ("REA") is appropriate to govern the ongoing operation, maintenance, and shared use of common infrastructure across the campus.
3.12 Closing and Post-Closing
The Firm will manage the closing and post-closing processes for the transactions described herein, including:
(a) Preparation and maintenance of master closing checklists for the land acquisitions (Stonebridge PSA closing and Meridian PSA closing) and the construction loan closing, including tracking of all conditions precedent, deliverables, and responsible parties.
(b) Pre-closing bring-down due diligence, including verification that all representations and warranties remain true and correct as of the applicable closing dates, confirmation of the absence of material adverse changes, and updates to title commitments, surveys, and UCC lien searches.
(c) Post-closing obligations tracking and compliance monitoring, including monitoring of post-closing deliverables (such as recorded documents, title policy issuance, UCC continuation filings, organizational and corporate maintenance filings, and any post-closing purchase price adjustments) and preparation of periodic post-closing compliance memoranda for the Client.
(d) Assembly and distribution of closing binders (physical and/or electronic) containing executed copies of all transaction documents.
4. Responsible Attorneys
The following attorneys will be primarily responsible for the Firm's work on this engagement:
Responsible Partner: Douglas Fairchild, Partner, Real Estate Practice Group, Calderwood & Harkness LLP. Mr. Fairchild will serve as the primary relationship partner for this engagement and as the primary point of contact for the Client on all significant matters relating to the Project.
Billing Partner: Angela Fontaine, Partner, Real Estate Practice Group, Calderwood & Harkness LLP. Ms. Fontaine will be responsible for billing, invoicing, and budget management for the engagement.
Lead Associate: Cynthia Ho, Associate, Real Estate Practice Group, Calderwood & Harkness LLP. Ms. Ho will handle day-to-day workstream management, drafting, and negotiations across all workstreams described in Section 3 of this Letter.
Working Associate: Grace Nakamura, Associate, Real Estate Practice Group, Calderwood & Harkness LLP. Ms. Nakamura will serve as the supporting associate for due diligence, document preparation, research, and other tasks as assigned.
Tax Specialist: Sylvia Hartwell, Partner, Tax Practice Group, Calderwood & Harkness LLP. Ms. Hartwell will advise on all tax-related matters described in Section 3.9 of this Letter, including the Virginia data center sales and use tax exemption analysis, entity structure and tax elections, cost segregation coordination, and Loudoun County equipment tax assessment matters.
Additional attorneys, paralegals, and staff may be assigned to the engagement as needed based on the volume and complexity of the work. The Firm will provide notice to the Client of any such additional assignments. Day-to-day communications regarding the Project may be directed to Mr. Fairchild or, for operational and drafting matters, to Ms. Ho, who will ensure that matters are escalated to Mr. Fairchild as appropriate.
5. Client Contacts
The following individuals are designated as the Client's primary contacts for this engagement:
Marcus Thorne, Chief Executive Officer, Ironhaven Data Centers LLC — overall project authority and strategic decisions.
Priya Dasgupta, Chief Financial Officer, Ironhaven Data Centers LLC — financial matters, construction loan negotiations, project budget, and tax coordination.
Leonard Castellano, Executive Vice President of Development, Ironhaven Data Centers LLC — development operations, EPC Agreement negotiations, entitlements and land use, and construction matters.
Julian Hargrove, Managing Partner, Ridgeline Capital Management LLC — equity sponsor communications, as directed by IHDC. For the avoidance of doubt, the Firm's communications with Mr. Hargrove will be at the direction and authorization of IHDC and do not constitute an attorney-client relationship between the Firm and Mr. Hargrove or Ridgeline Capital Management LLC.
The Client may modify its designated contacts at any time by written notice to the Firm.
6. Fees and Billing Arrangements
6.1 Hourly Rates
Fees for the Firm's legal services in connection with this engagement will be based on the Firm's standard hourly rates for the attorneys and paralegals working on the matter. Rates vary by the seniority, experience, and practice area of the individual timekeepers. A schedule of the Firm's current hourly rates for the timekeepers anticipated to work on this engagement is attached hereto as Exhibit A (the "Rate Schedule"). The rates set forth in the Rate Schedule are subject to periodic adjustment, which typically occurs on an annual basis effective January 1 of each year. The Firm will provide the Client with advance written notice of any rate adjustment not less than thirty (30) days prior to the effective date of such adjustment.
6.2 Billing and Payment
Angela Fontaine will serve as the billing partner for this engagement and will be responsible for the preparation and issuance of all invoices. The Firm will render monthly invoices to the Client, which will detail the time entries of each attorney and paralegal who worked on the matter during the billing period, including a description of the tasks performed and the time spent on each task, as well as an itemization of all disbursements and out-of-pocket expenses incurred during the period. Payment of each invoice is due within thirty (30) days of the invoice date. All invoices will be directed to Priya Dasgupta, Chief Financial Officer, at the Client's offices at 44680 Prentice Drive, Suite 200, Ashburn, Virginia 20147, or to such other address or email address as the Client may designate from time to time. If the Client disputes any portion of an invoice, the Client agrees to notify the Firm in writing within fifteen (15) days of receipt, and the parties will work in good faith to resolve any such dispute promptly. Undisputed amounts shall remain due and payable within the thirty (30) day payment period regardless of any dispute as to other amounts.
6.3 Disbursements and Expenses
In addition to professional fees, the Client will be responsible for the reimbursement of all reasonable out-of-pocket expenses and disbursements incurred by the Firm in connection with this engagement. Such disbursements may include, without limitation, filing fees (including fees payable to the Virginia State Corporation Commission and the Loudoun County Clerk's Office for the recording of deeds, deeds of trust, and other instruments), recording fees, courier and delivery charges, travel expenses (including airfare, ground transportation, lodging, and meals for travel reasonably necessary in connection with the engagement), title search and examination costs, photocopying and printing costs, and third-party vendor costs advanced by the Firm on behalf of the Client. Filing fees, recording fees, and other governmental charges will be passed through to the Client at cost, without markup. Travel expenses will be incurred in accordance with the Firm's standard travel policy, and the Firm will exercise reasonable judgment in incurring such expenses.
6.4 Retainer.  No retainer deposit is required at the commencement of this engagement. The Firm reserves the right to request a retainer or advance deposit in the future if, in the Firm's reasonable judgment, the outstanding balance of unpaid invoices or the anticipated volume of work warrants such a request.
6.5 Budget Estimate
A preliminary budget estimate for the engagement, broken down by workstream, will be provided to the Client under separate cover in the Staffing Plan and Budget Estimate Memorandum dated March 14, 2025. The Client acknowledges that budget estimates are non-binding projections provided for planning purposes only and are subject to revision based on the actual scope, complexity, and duration of the matters as they develop. Material changes in scope, the involvement of additional parties, unforeseen complications in due diligence or negotiations, or protracted entitlement proceedings may result in fees that exceed the initial budget estimate. The Firm will endeavor to keep the Client informed of any material developments that are likely to result in a significant deviation from the budget estimate and will work with the Client to manage costs effectively.
7. Retention of Local Counsel and Other Professionals
The Firm intends to retain Ashcroft & Wynn, P.C. ("A&W"), located at 25 West Market Street, Leesburg, Virginia 20176 (Thomas Ashcroft, Lead Partner), as local zoning counsel in connection with the ZMOD application, proffer negotiations, appearances before the Loudoun County Planning Commission and Board of Supervisors, and related Loudoun County land use matters. A&W has significant experience with data center entitlement matters in Loudoun County and is well-positioned to serve as counsel of record before the applicable Loudoun County boards and commissions. The fees and expenses of local counsel will be the responsibility of the Client (IHDC) and may, at the Client's election, be billed through C&H (in which case such fees will appear as a disbursement on the Firm's invoices) or directly by A&W to the Client. The Firm will coordinate the work of A&W with the other workstreams of the engagement to ensure consistency and efficiency.
In addition, the Firm will coordinate with, but does not serve as counsel to, the various third-party consultants and advisors engaged by IHDC in connection with the Project. These include, but are not limited to, the following:
•  Cornerstone Land Use Consulting, LLC (Alan Mercer, Principal Consultant) — land use and planning consulting
•  Pendleton Environmental Associates, Inc. — environmental site assessments
•  Brannigan Geotechnical Engineering, LLC — geotechnical investigations
•  Kestrel Infrastructure Advisors, LLC — owner's representative services
•  Lumen Ridge Engineering, PLLC — surveying
•  Greystone Appraisal Partners, LLC — appraisal services
•  Northgate Insurance Brokerage, LLC (William Keane, Account Executive) — insurance brokerage
•  Fielding & Associates, CPAs (Robert Fielding, CPA) — accounting and tax advisory
The Firm does not represent any of the foregoing consultants or advisors, and the engagement of such parties is the sole responsibility of the Client. The Firm will review and coordinate with the work product of these consultants as described in Section 3 of this Letter to the extent necessary for the legal workstreams within the Firm's scope.
8. Conflicts of Interest
The Firm has conducted a conflict of interest check as of March 12, 2025, in accordance with the Firm's standard procedures and the requirements of the applicable rules of professional conduct. Based on that conflict check, the Firm has not identified any conflicts of interest that would prevent the Firm from undertaking this engagement. The conflict check encompassed all known parties to the transactions contemplated by this engagement, including Ironhaven Data Centers LLC, Ridgeline Capital Partners Fund IV, LP, RCP Digital Holdings LLC, Blackthorn Realty Group, Inc., Meridian Acres LLC, Titan-McAllister Construction Group, LLC, Summit National Bank, N.A., Cascade Commercial Lending Corp., Harborview Trust Company, and Vantage Power Cooperative.
The Client acknowledges that Calderwood & Harkness LLP is a large, multi-office law firm with attorneys practicing in numerous jurisdictions and across a wide range of practice areas. In the ordinary course of its practice, the Firm may from time to time represent other clients whose interests may be adverse to those of IHDC in matters that are wholly unrelated to this engagement and to the Stonebridge Campus development. By executing this Letter, the Client consents to the Firm's representation of other clients in matters unrelated to this engagement, provided that such representation does not involve the use of confidential information obtained from IHDC and does not create a conflict that would materially impair the Firm's ability to represent IHDC in this engagement. This consent does not extend to any matter in which the Firm's representation of another client would be directly adverse to IHDC in the same transaction, dispute, or proceeding.
Should a conflict of interest arise during the course of this engagement, the Firm will promptly notify the Client and take all appropriate steps in accordance with the applicable rules of professional conduct, which may include seeking informed consent from the affected parties or, if consent cannot be obtained, withdrawing from the representation of one or more affected clients as required.
9. Confidentiality
The Firm will maintain the confidentiality of all information provided by the Client, or obtained by the Firm on behalf of the Client, in connection with this engagement, in accordance with the Firm's professional obligations and the applicable rules of professional conduct. The Firm will not disclose such confidential information to any third party without the Client's prior consent, except as required by law, court order, or the Firm's professional obligations, or as reasonably necessary for the performance of the Firm's services under this engagement.
Confidential information may be shared within the Firm on a need-to-know basis among attorneys, paralegals, and staff working on this engagement. Confidential information may also be shared with local counsel (Ashcroft & Wynn, P.C.) to the extent necessary for A&W to perform its role in the engagement, subject to A&W's own obligations of confidentiality. The Firm will take reasonable precautions to safeguard the Client's confidential information, including the use of secure electronic communication and document management systems.
10. Document Retention
Upon the conclusion of this engagement, the Firm will retain the Client's files and documents in accordance with the Firm's standard document retention policy, a copy of which will be provided to the Client upon request. The Firm's current policy provides for the retention of closed matter files for a period of ten (10) years following the conclusion of the engagement, after which the files may be destroyed in the Firm's discretion upon thirty (30) days' prior written notice to the Client, unless the Client requests return or further retention of the files. The Client may request the return of original documents at any time during or after the engagement, and the Firm will promptly comply with any such request, subject to the Firm's right to retain copies for its records and to comply with its professional obligations.
11. Termination
Either party may terminate this engagement at any time upon written notice to the other party. Upon termination by either party, the Client will remain responsible for the payment of all fees, disbursements, and expenses incurred through the date of termination, including any fees for time spent by the Firm in connection with the orderly transition of the matter to successor counsel. Upon termination, the Firm will cooperate fully in the orderly transition of the matter, including the prompt delivery of all files, documents, and work product to the Client or to successor counsel as directed by the Client, subject to the satisfaction of all outstanding financial obligations of the Client to the Firm. The Firm's obligation to provide cooperation in connection with any such transition shall survive the termination of this engagement.
12. Governing Law
This engagement letter and the terms and conditions set forth herein shall be governed by and construed in accordance with the laws of the Commonwealth of Virginia, without regard to its conflict of laws principles.
13. Limitations on Scope
The scope of this engagement is as described in Section 3 of this Letter. For the avoidance of doubt, the following matters are expressly excluded from the scope of this engagement and will not be performed by the Firm unless separately agreed to in a written amendment to this Letter or in a separate engagement letter:
(a) Representation of IHDC or any of its affiliates in tenant leasing negotiations for the Stonebridge Campus, including the negotiation and drafting of data center lease, license, or colocation agreements;
(b) Securities or capital markets matters, including any offering of equity or debt securities by IHDC, Ridgeline Fund IV, or any affiliated entity;
(c) Labor and employment matters, including employment agreements, benefit plans, wage and hour compliance, or employment-related disputes;
(d) Litigation, arbitration, or other dispute resolution proceedings of any nature, unless separately agreed to in writing; and
(e) PJM Interconnection, Federal Energy Regulatory Commission ("FERC"), or other energy regulatory matters. To the extent that the Project requires analysis of or compliance with PJM interconnection requirements, FERC regulations, or other energy regulatory matters, the Client should retain specialized energy regulatory counsel with expertise in those areas.
The Firm will endeavor to alert the Client to any issues that the Firm identifies in the course of this engagement that may fall outside the scope described herein but that may require the Client's attention or the engagement of additional counsel.
14. Agreement and Acceptance
We are delighted to have the opportunity to represent Ironhaven Data Centers LLC in connection with the Stonebridge Data Center Campus development, and we look forward to working closely with you and your team throughout the Project. Please indicate your acceptance of the terms and conditions set forth in this Letter by countersigning where indicated below and returning one signed copy to us by email or U.S. mail. This Letter, together with Exhibit A attached hereto, constitutes the entire agreement between the parties with respect to the subject matter hereof and supersedes all prior discussions, understandings, and agreements, whether written or oral, relating to the Firm's engagement by the Client in connection with the Project.
If you have any questions regarding any of the terms of this Letter, please do not hesitate to contact me at (212) 554-7100 or dfairchild@calderwoodharkness.com.
Very truly yours,
CALDERWOOD & HARKNESS LLP
By: ________
Name: Douglas Fairchild
Title: Partner
Calderwood & Harkness LLP 425 Lexington Avenue New York, NY 10017 Telephone: (212) 554-7100
Email: dfairchild@calderwoodharkness.com
Additional Office: 1900 K Street NW, Suite 800 Washington, DC 20006 Telephone: (202) 661-4200
ACKNOWLEDGMENT AND ACCEPTANCE
The undersigned, on behalf of Ironhaven Data Centers LLC, hereby acknowledges receipt of the foregoing Engagement Letter dated March 12, 2025, from Calderwood & Harkness LLP, and agrees to the terms and conditions set forth therein, including but not limited to the scope of engagement, fee arrangements, conflict of interest provisions, and limitations on scope described herein.
IRONHAVEN DATA CENTERS LLC
By: ________
Name: Marcus Thorne
Title: Chief Executive Officer
Date: ________
Enclosures:
Exhibit A: Current Hourly Rate Schedule
cc:
Priya Dasgupta, Chief Financial Officer, Ironhaven Data Centers LLC Leonard Castellano, Executive Vice President of Development, Ironhaven Data Centers LLC Angela Fontaine, Partner, Calderwood & Harkness LLP Cynthia Ho, Associate, Calderwood & Harkness LLP
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CALDERWOOD & HARKNESS LLP Attorneys at Law

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CALDERWOOD & HARKNESS LLP

ACKNOWLEDGMENT AND ACCEPTANCE

IRONHAVEN DATA CENTERS LLC

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