Foreign investment in construction activities, with the exception of construction services incidental to mining and mechanical engineering services activities, is limited depending on the project amount to up to 90% of equity ownership. This applies only for firms applying for a Certificate A, which allows them to carry out construction works for the government and private sector. Firms applying for Certificate B, which allows them to carry out construction works for the private sector only, are not bound by such equity limitations. For the purpose of the OECD FDIRRI, it is assumed that existing equity restrictions applicable to Certificate A firms, which seek to serve the public sector, affect more prominently the civil engineering contructions segment.

"ANNEX I - SCHEDULE OF BRUNEI DARUSSALAM
Sector: Construction Services
Obligations Concerned: National Treatment (Article 9.4), Performance Requirements (Article 9.10), Local Presence (Article 10.6)
Measures: Architects, Professional Engineers and Quantity Surveyors Order 2011, Building Control Order 2011 (Draft), Building Control Regulations (Draft), Procedures of Contractors and Suppliers Registration, Ministry of Development (Edition 2009), Administrative Measures and Guidelines
[...] 
Description: Investment [...]
1. Foreign nationals and enterprises are not allowed to supply construction services such as: general construction work for building services, general construction work for civil engineering, installation and assembly work services, building completion and finishing work services, except mining, and mechanical engineering services, unless: (a) through an enterprise established in Brunei Darussalam; (b) they register for either Certificate A or Certificate B, as a contractor or supplier; or (c) they comply with any requirement to transfer technology or other proprietary knowledge to persons in Brunei Darussalam as long as such requirement to transfer technology or other proprietary knowledge does not unreasonably prejudice the legitimate interests of the owner of technology or proprietary knowledge and is not for the purposes of commercial exploitation by Brunei Darussalam.
2. In the case of Certificate A, a foreign national or enterprise may not own equity shareholding other than what is prescribed in the table below, in any enterprise that applies to be registered as a contractor or supplier:
Table - Class / Project Threshold / Level of Foreign Equity Allowed
  I / Up to BND 50 000 / None
 II / Exceeding BND 50 000 but not more than BND 250 000 / None
III / Exceeding BND 250 000 but not more than BND 500 000 / 20 per cent
IV / Exceeding BND 500 000 but not more than BND 1.5 million / 50 per cent
 V / Exceeding BND 1.5 million but not more than BND 5 million / 70 per cent
VI / Exceeding BND 5 million / 90 per cent
 Building Specialist and Supplier / No threshold / 90 per cent
Mechanical and Electrical Specialist and Supplier / No threshold / 90 per cent
3. For greater certainty, Certificate A refers to certificates which are required for participating in government and private projects, whilst Certificate B refers to certificates which are required for participating in private projects only." (ANNEX I - SCHEDULE OF BRUNEI DARUSSALAM, Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP))
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"PART VII -LICENSING OF BUILDERS 
Interpretation. 
42. (1) In this Part, unless the context otherwise requires "building works" means any building works to which Part II applies; "minor specialist building works" means (a} specialist building works associated with minor building works; (b) structural steelwork comprising fabrication and erection work for structures with a cantilever length of not more than 3 metres, a clear span of less than 6 metres and a plan area not exceeding 150 square metres; (c) pre-cast concrete work compnsmg casting of pre-cast reinforced concrete slabs or planks on site; 
(2) In this Part (a) a person carries on the business of a builder if the person carries out, or undertakes to carry out, (whether exclusively or in conjunction with any other business) general building ·works for or on behalf of another person for a fixed sum, percentage, or valuable consideration, or reward other than wages, but not if the person carries out, or undertakes to carry out, general building works only as a sub-contractor; (b) a person carries on the business of a builder if the person carries out, or undertakes to carry out, (whether exclusively or in conjunction with any other business) any specialist building works for or on behalf of another person for a fixed sum, percentage, or valuable consideration or reward other than wages; (c) a person carries out general building works or specialist building works whether that person carries it out personally, or directly or indirectly causes it to be carried out; (d) a person shall be deemed to carry on the business of a builder if he carries out general building works or specialist building works, as the case may be, on or in respect of a building for himself; and {e} a person undertakes to carry out general building works or specialist building works if that person enters into a contract to carry it out or submits a tender or makes an offer to carry it out. 
[...]
Prohibition against unlicensed builders.
43. (1) Subject to this Order, no person shall - (a} advertise or hold himself out or conduct himself in any way or by any means as a person who is authorised to carry on the business of a builder in Brunei Darussalam; or {b) assume, take or use (either alone or in combination with any other word, letter or device) the name, title or description of "licensed builder", or any name, title or description calculated to lead others to believe he is so licensed, or by words or conduct hold himself out as being so licensed, unless he is in possession of a builder's licence. 
(2) Subject to this Order, no person shall - (a) carry on the business of a builder in Brunei Darussalam unless he is in possession of a builder's licence; (b) carry on a business carrying out, or undertaking to carry out, whether exclusively or in conjunction with any other business, general building works and minor specialist building works or minor specialist building works only, unless he is in possession of a builder's licence; 
[...]
Classes of builder's licences.
44. A licence may be granted under this Part to a builder authorising him to carry on such classes of business of a builder as may be prescribed. [...]" (BUILDING CONTROL ORDER, 2014, as amended)
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"[Table of requirements per class of builder licence - text not reproduced here] (Ministry of Development, Builder License Registration Requirement and Contractor Registration Certificate)

ANNEX I - SCHEDULE OF BRUNEI DARUSSALAM, Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP)
BUILDING CONTROL ORDER, 2014, as amended
Ministry of Development, Builder License Registration Requirement and Contractor Registration Certificate
[<a href="https://www.mfat.govt.nz/assets/Trade-agreements/TPP/Annexes-ENGLISH/Annex-I.-Brunei.pdf">CPTPP</a>],[<a href="https://www.agc.gov.bn/AGC%20Images/LAWS/Gazette_PDF/2014/EN/s069.pdf">Order</a>],[<a href="http://abci.gov.bn/SiteAssets/Perkhidmatan%20ABCi/Pendaftaran%20Syarikat/Lesen%20Pembina/Jadual%20A1%20kelas%20I%20ke%20VI.pdf">Table</a>]