Short answer: A main contractor in Singapore is the firm that signs the building contract with the owner and takes overall responsibility for delivering the works: programme, quality, site safety, subcontractors and statutory compliance. For works that need plan approval, the main contractor must hold a BCA builder’s licence, and public sector jobs also require CRS registration at a suitable grade.
Owners often hear the terms main contractor, general builder and principal contractor used loosely. This article explains what the role covers in practice, which licences and registrations apply, how the main contractor differs from consultants and subcontractors, and how to appoint one without leaving gaps in responsibility.
Key takeaways
- The main contractor holds the contract with the owner and answers for the whole of the works, including work done by subcontractors.
- BCA says that, generally, only main contractors need a General Builder’s Licence; Class 2 builders are limited to projects of $6 million or less, while Class 1 has no value limit.
- Public sector tenders require CRS registration, and each CW01 grade carries a tendering limit, from $0.8 million for C3 to unlimited for A1.
- Safety duties under the WSH Act follow control of the site, so the main contractor normally carries heavy safety obligations as the party running the worksite.
- Appointment should follow a clear sequence: define the scope, choose the procurement route, check licences and track record, compare tenders and sign a standard form contract.
What is a main contractor?
The main contractor is the single party that contracts directly with the building owner or developer to carry out the construction works. Everyone else on the construction side, from piling specialists to M&E installers, usually works under the main contractor.
In a traditional contract, the owner’s consultants (architect, structural engineer, M&E engineer) design the building and the main contractor builds to their drawings. In a design and build contract, the main contractor also takes on design responsibility and engages the consultants itself. Our earlier article on design and build in Singapore explains that model in detail.
Either way, the defining feature is single-point responsibility for construction. If a subcontractor’s work is late or defective, the owner looks to the main contractor, not to the subcontractor.
What does a main contractor do day to day?
The main contractor plans, resources, coordinates and supervises the works from site possession to handover and through the defects liability period. The duties fall into six broad groups.
Planning and programme
The main contractor prepares the master programme, sequences trades and tracks progress against key dates. On occupied buildings, such as factories that keep running during alteration works, this includes phasing the works around the owner’s operations.
Procurement and subcontract management
Most main contractors self-perform some trades and subcontract others. They tender, appoint and pay subcontractors and suppliers, check their submissions and hold them to the programme. Payment between the parties is governed by the contract and by the Building and Construction Industry Security of Payment Act, which gives main contractors, subcontractors, consultants and suppliers a statutory route to payment claims and adjudication.
Site safety and health
Under the Workplace Safety and Health Act, duties attach to employers, principals and occupiers. MOM explains that, outside registered factories, the occupier is the person who has control of the premises, and a principal who engages contractors must make sure they can do the work safely. Because the main contractor normally controls the worksite and engages the subcontractors, it carries a large share of these duties in practice.
Quality and technical coordination
The main contractor submits method statements, shop drawings and material samples, runs inspections and test regimes, and coordinates structure, architecture and services so that clashes are resolved before they reach site.
Statutory submissions and site supervision
The building permit application for structural works is made jointly by the developer, the Qualified Person (QP) and the builder. The QP appoints the site supervisors. For large works, BCA sets full-time supervision levels by value; for example, works above $7.5 million up to $15 million need one Resident Technical Officer at all stages. The main contractor works alongside these supervisors and keeps the site records they need.
Commercial management and handover
The main contractor values progress, submits payment claims, prices variations, compiles as-built drawings and operation manuals, and rectifies defects during the defects liability period.
Which licences and registrations does a main contractor need?
A main contractor carrying out building works that need plan approval must hold a BCA builder’s licence. A contractor tendering for public sector work also needs registration under BCA’s Contractors Registration System (CRS).
Builder’s licence
BCA states that the licensing requirement applies to both public and private sector projects and that generally, only main contractors need a General Builder’s Licence. Subcontractors usually do not, unless they carry out specialist works such as piling or structural steelwork, which need a Specialist Builder’s Licence.
| Licence | Project value | Minimum paid-up capital (corporations) |
|---|---|---|
| General Builder Class 1 | Any value | $300,000 |
| General Builder Class 2 | $6 million or less | $25,000 |
| Specialist Builder | Any value within the licensed category | $25,000 |
Each licensed builder must appoint an Approved Person, who directs the management of its building works, and a Technical Controller, who oversees how the works are carried out.
CRS registration and grades
CRS is BCA’s national registry of construction firms. BCA says registration is needed to tender for public sector construction projects, to act as a first-level subcontractor on them, and, since 1 June 2025, to employ construction S Pass or Work Permit holders. General building is workhead CW01, graded from A1 down to C3.
Each grade carries a tendering limit. For the period 1 July 2026 to 30 June 2027, BCA lists CW01 limits of $105 million for A2, $50 million for B1, $16 million for B2 and $5 million for C1, with A1 unlimited. Private owners are not bound by these limits, but many use them as a quick indicator of a contractor’s scale.
How is the main contractor different from consultants and subcontractors?
Consultants design and certify; the main contractor builds and is responsible for the means and methods; subcontractors deliver defined packages for the main contractor. The table sets out the usual split under a traditional contract.
| Party | Contracts with | Main responsibility |
|---|---|---|
| Owner or developer | Consultants and main contractor | Funding, brief, decisions, statutory duties as developer |
| Qualified Person and consultants | Owner (or the main contractor under design and build) | Design, statutory plan submissions, supervision and certification |
| Main contractor | Owner | Building the works, programme, safety, quality, subcontractor control |
| Nominated or domestic subcontractors | Main contractor | Specific trades such as piling, M&E, facade or lifts |
| Suppliers | Main contractor or subcontractors | Materials and equipment to specification |
Nominated subcontractors are chosen by the owner but still contract with the main contractor. The contract should state clearly how far the main contractor is responsible for their performance, because standard forms treat this differently.
How do you appoint a main contractor in Singapore?
Define the scope and procurement route first, then shortlist on licences, grade and relevant track record, then compare tenders on both price and quality before signing a standard form contract.
- Set the brief and budget. Confirm the scope, target completion date, operational constraints and budget range with your consultants or a quantity surveyor.
- Choose the procurement route. Decide between a traditional design-bid-build contract and design and build, based on how much design risk you want to transfer.
- Prequalify. Check the builder’s licence class and CRS grade on BCA’s directory, safety record, financial standing and similar completed projects. Our guide to choosing a design and build contractor lists useful questions.
- Tender. Issue the same drawings, specifications and contract conditions to every shortlisted firm, with a clear return date and pricing schedule.
- Evaluate. Compare price, programme, methodology, key staff, safety plans and qualifications. Clarify exclusions before you compare totals.
- Award and sign. Use a recognised standard form, such as the SIA conditions for private projects or PSSCOC for public projects, and attach the agreed tender clarifications.
- Mobilise. Hold a kick-off meeting, confirm site possession, insurances, bonds and the reporting structure before work starts.
Common mistakes owners make
Most problems trace back to unclear scope or weak checks at appointment, not to the build itself.
- Appointing on price alone. The lowest tender often hides exclusions or provisional sums that return as variations.
- Splitting the works across several direct contractors. This removes single-point responsibility and leaves the owner to coordinate interfaces and site safety.
- Not checking the licence class. A Class 2 general builder cannot take on a project above $6 million.
- Vague operational constraints. For A&A works in a live building, noise windows, access routes and shutdowns must be written into the contract, not agreed later.
- Weak payment terms. Payment periods, retention and documentation requirements should be clear so that claims under the contract and the SOP Act run smoothly.
How Nippon Builders can help
Nippon Builders acts as main contractor for general building construction, design and build and addition and alteration works for public and private clients. Our core values are excellence, teamwork, honesty, integrity, compliance and safety, and our directors take a hands-on approach on site.
Recent and current main contract work includes building works for HDB at Serangoon North Contract 21 (330 dwelling units), a new 5-storey single-user ramp-up warehouse with ancillary office for Lim Siang Huat at Pioneer Turn, and A&A works to seven buildings along Sungei Gedong Road and one along Old Choa Chu Kang Road for DSTA. You can see more in our portfolio and full project references.
Planning a new building or alteration works and need a main contractor who will own the whole delivery? Contact Nippon Builders or call +65 6898 2500 to discuss your project.
Frequently asked questions
Yes, for building works that require plan approval by the Commissioner of Building Control. BCA states that generally only main contractors need a General Builder’s Licence. Class 1 licensees can take projects of any value, while Class 2 licensees are limited to projects of $6 million or less. Specialist works such as piling need a separate Specialist Builder’s Licence.
The main contractor signs the contract with the owner and is responsible for the whole of the works. Subcontractors are engaged by the main contractor to carry out specific trades, such as piling, M&E or facade works. The owner usually has no direct contract with subcontractors, so defects or delays in their work are claimed against the main contractor.
In everyday use, yes. Both terms describe the firm that contracts directly with the owner and manages the construction. In Singapore the licence held by such firms is called a General Builder’s Licence, which is why main contractors are also described as general builders. The legal duties come from the contract and the relevant Acts, not the label.
CRS registration is mainly needed for public sector tenders and, since 1 June 2025, for firms employing construction S Pass or Work Permit holders. Private owners are not required by CRS rules to use a registered firm, but many check the CRS grade and workhead as an indication of a contractor’s financial capacity, track record and scale.
Safety duties under the Workplace Safety and Health Act are shared. Employers protect their own workers, principals must engage competent contractors, and the occupier, the party in control of the premises, must keep the workplace safe for everyone on it. On most building sites the main contractor controls the site and carries a large share of these duties.