EX-5.1 2 ea023234701ex5-1_onecons.htm OPINION OF HARNEY WESTWOOD & RIEGELS

Exhibit 5.1

Harney Westwood & Riegels 3501 The Center 99 Queen’s Road Central Hong Kong Tel: +852 5806 7800 Fax: +852 5806 7810

19 March 2025

raymond.ng@harneys.com

+852 5806 7883

063850-0003-RLN

OneConstruction Group Limited

一建築集團有限公司

Harneys Fiduciary (Cayman) Limited

4th Floor, Harbour Place

103 South Church Street, P.O. Box 10240

Grand Cayman KY1-1002

Cayman Islands

Dear Sir or Madam

OneConstruction Group Limited一建築集團有限公司 (the Company)

We are lawyers qualified to practise in the Cayman Islands and have acted as Cayman Islands legal advisers to the Company in connection with the Company’s registration statement on Form S-8, including all amendments or supplements thereto, to be filed on or around the date of this opinion with the Securities and Exchange Commission (the Commission) under the United States Securities Act of 1933, as amended (the Securities Act) (the Registration Statement), relating to the registration of 3,000,000 ordinary shares of par value US$0.0001 per share (the Shares) under the Company’s 2025 equity incentive plan (the 2025 Equity Incentive Plan).

We are furnishing this opinion as Exhibit 5.1 to the Registration Statement.

For the purposes of giving this opinion, we have examined the Documents (as defined in Schedule 1) which we regard as necessary in order to issue this opinion. We have not examined any other documents, official or corporate records or external or internal registers and have not undertaken or been instructed to undertake any further enquiry or due diligence in relation to the transaction which is the subject of this opinion.

The British Virgin Islands is Harneys Hong Kong office’s main jurisdiction of practice. Jersey legal services are provided through a referral arrangement with Harneys (Jersey) which is an independently owned and controlled Jersey law firm. Resident Partners: M Chu | JP Engwirda | Y Fan | S Gray | P Kay | MW Kwok |
IN Mann | R Ng ATC Ridgers | PJ Sephton 612675770.2 Anguilla | Bermuda | British Virgin Islands | Cayman Islands Cyprus | Hong Kong | Jersey | London | Luxembourg Montevideo | São Paulo | Shanghai | Singapore harneys.com

In giving this opinion we have relied upon the assumptions set out in Schedule 2 which we have not independently verified.

Based solely upon the foregoing examinations and assumptions and upon such searches as we have conducted and having regard to legal considerations which we deem relevant, and subject to the qualifications set out in Schedule 3, we are of the opinion that under the laws of the Cayman Islands:

1 Existence and Good Standing. The Company is a company duly incorporated with limited liability, and is validly existing and in good standing under the laws of the Cayman Islands. The Company is a separate legal entity and is subject to suit in its own name.

2 Valid Issuance of Shares. The Shares when authorised to be issued, sold and paid for in the manner described in the 2025 Equity Incentive Plan and in accordance with the Resolutions (as defined in Schedule 1) and, when allotted, issued and fully paid for in accordance with the 2025 Equity Incentive Plan and the Registration Statement, and when the names of the shareholders are entered in the register of members of the Company, the Shares will be validly issued, fully paid and non-assessable.

This opinion is confined to the matters expressly opined on herein and given on the basis of the laws of the Cayman Islands as they are in force and applied by the Cayman Islands courts at the date of this opinion. We have made no investigation of, and express no opinion on, the laws of any other jurisdiction. Except as specifically stated herein, we express no opinion as to matters of fact.

In connection with the above opinion, we hereby consent to the filing of this opinion as an exhibit to the Registration Statement and to the reference made to this firm in the Registration Statement under the heading “Indemnification of Directors and Officers”. In giving such consent, we do not thereby admit that we come within the category of persons whose consent is required under Section 7 of the U.S. Securities Act of 1933, as amended, or the Rules and Regulations of the Commission thereunder.

This opinion is limited to the matters referred to herein and shall not be construed as extending to any other matter or document not referred to herein.

This opinion shall be construed in accordance with the laws of the Cayman Islands.

Yours faithfully

/s/ Harney Westwood & Riegels

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Schedule 1

List of Documents and Records Examined

1 The certificate of incorporation of the Company dated 14 June 2024;

2 The amended and restated memorandum and articles of association of the Company adopted by a special resolution of the Company dated 30 December 2024;

3 The register of directors the Company provided to us on 12 March 2025;

Copies of 1 to 3 above have been provided to us by the Company (the Corporate Documents, and together with 4 to 8 below, the Documents).

4 A copy of executed unanimous written resolutions of the directors of the Company dated 27 February 2025 (the Resolutions);

5 a certificate of good standing in respect of the Company issued by the Registrar of Companies dated 14 March 2025;

6 A certificate from a director of the Company dated 18 March 2025, a copy of which is attached hereto (the Director’s Certificate);

7 The Registration Statement filed with the Commission on 18 March 2025; and

8 A copy of the 2025 Equity Incentive Plan.

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Schedule 2

Assumptions

1 Authenticity of Documents. Copy documents or drafts of documents provided to us are true and complete copies of, or in the final forms of, the originals. All original Documents are authentic, all signatures, initials and seals are genuine.

2 Corporate Documents. All matters required by law to be recorded in the Corporate Documents are so recorded, and all corporate minutes, resolutions, certificates, documents and records which we have reviewed are accurate and complete, and all facts expressed in or implied thereby are accurate and complete as at the date of the passing of the Resolutions.

3 Director’s Certificate. The contents of the Director’s Certificate are true and accurate as at the date of this opinion and there is no information not contained in the Director’s Certificate that will in any way affect this opinion.

4 No Steps to Wind-up. The directors and shareholders of the Company have not taken any steps to appoint a liquidator of the Company and no receiver has been appointed over any of the Company’s property or assets.

5 Resolutions. The Resolutions remain in full force and effect.

6 Unseen Documents. Save for the Documents provided to us there are no resolutions, agreements, documents or arrangements which materially affect, amend or vary the transactions envisaged in the Registration Statement.

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Schedule 3

Qualifications

1 Foreign Statutes. We express no opinion in relation to provisions making reference to foreign statutes in the Registration Statement.

2 Commercial Terms. Except as specifically stated herein, we make no comment with respect to any representations and warranties which may be made by or with respect to the Company in any of the documents or instruments cited in this opinion or otherwise with respect to the commercial terms of the transactions the subject of this opinion.

3 Meaning of Non-Assessable. In this opinion the phrase non-assessable means, with respect to the issuance of shares, that a shareholder shall not, in respect of the relevant shares, have any obligation to make further contributions to the Company’s assets (except in exceptional circumstances, such as involving fraud, the establishment of an agency relationship or an illegal or improper purpose or other circumstances in which a court may be prepared to pierce or lift the corporate veil).

4 Good Standing. The Company shall be deemed to be in good standing at any time if all fees (including annual filing fees) and penalties under the Law have been paid and the Registrar of Companies has no knowledge that the Company is in default under the Law.

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Annex

Director’s Certificate

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