A&A works in Singapore: when a landed renovation needs BCA approval and a Professional Engineer.
The line between a renovation and an addition-and-alteration is the line between a contractor's quotation and a submission to the Building and Construction Authority under a Qualified Person. Cross it without knowing, and the cheapest renovation in the street becomes the most expensive regularisation. Here is where the line runs, who signs, and what it costs.
Renovation or A&A: where the line runs
A renovation changes what a house looks like. An addition and alteration changes what holds it up, how big it is, or how it sits in its envelope. Painting, flooring, cabinetry, sanitary ware, lighting and non-structural partitions are renovation; no authority needs to know. Anything that touches structure, floor area or the building envelope is A&A, and under the Building Control Act it requires plans prepared and endorsed by a Qualified Person and approved by BCA before the work starts, together with URA planning permission where floor area or envelope changes.
The test is not how big the job feels. A single opening cut through a load-bearing wall to join a kitchen to a dining room is A&A. A full repaint and re-tile of four storeys is not.
The trigger list
If your landed project includes any of these, it is A&A and needs a Qualified Person and BCA approval. Most also need URA planning permission.
- Removing, cutting or opening a load-bearing wall or column, including the party wall of a terrace or semi-detached house
- Adding an attic, mezzanine or additional storey
- Extending the building footprint, front, side or rear, including a new car porch roof
- Changing the roof structure or converting a pitched roof to a usable space
- Adding or relocating a staircase, or cutting a new void through a slab
- A swimming pool, a basement, or a retaining wall
- Raising or lowering a floor slab, or adding a lift shaft
- Any work that changes the gross floor area or the position of the building within its setbacks and height envelope
CVC Engineers' guide to A&A submission in Singapore walks through the same boundary from the engineer's side, including the minor works categories that attract a lighter submission.
Who the Qualified Person is
For structural works, the Qualified Person is a Professional Engineer in civil or structural engineering, registered with the Professional Engineers Board. They design the structural works, endorse the plans in their own name, submit them to BCA, obtain the permit to commence structural works, supervise construction at the stages the regulations require, and certify completion. For the architectural plans, a registered architect may act as Qualified Person for the planning and building plan submissions.
Two facts matter more than any other. The engineer's responsibility is personal and statutory; it does not transfer to the builder. And the engineer must be independent of the builder: the person who certifies the structure cannot be the person paid to build it as cheaply as possible. On a Design & Build project this independence is the owner's protection against the builder designing to its own convenience, which is why we insist on it rather than resent it.
The sequence, from URA to CSC
- URA planning permission, where floor area, envelope or use changes. Typically four to eight weeks; longer if a neighbour objects.
- BCA building plan approval, on plans endorsed by the Qualified Person. Six to ten weeks.
- Structural plan clearance and the permit to commence structural works, under the Professional Engineer. No permit, no demolition.
- Construction under supervision, with the PE inspecting at the stages the regulations name, and site supervisors where required.
- Other clearances as the scope requires: PUB for drainage, SCDF for fire safety, NParks for trees, LTA for anything touching the road.
- Certificate of Statutory Completion, the document that says the house is lawful as built. Without it, the works are not finished, whatever the builder says.
The full catalogue of submission types, and which authority owns each, is set out in this guide to BCA submission services in Singapore.
What it costs
The Professional Engineer's fee for an A&A scales with the complexity of the structure and the number of submissions, not with the size of the renovation budget. A single opening in a wall is a modest fee; a new attic and a rear extension on a semi-detached house is a larger one, with site supervision through the structural stages. CVC Engineers publish transparent 2026 pricing for PE endorsement, which is unusual in the profession and a fair benchmark for the line on your quotation. Authority fees, GST and the construction itself sit on top; see our 2026 cost guide for the construction bands.
Set against the alternative, the fee is small. An unapproved opening discovered during a sale, or after a crack appears next door, costs a regularisation submission, remedial works, and a conveyancing delay measured in months.
What happens if you skip it
Works done without approval are unauthorised. BCA can require them to be regularised or removed. Home insurance may not respond to a loss involving unauthorised structure. The house becomes difficult to sell or to finance until a Professional Engineer has assessed the works and BCA has accepted them. And if the unauthorised work affected a shared wall, the neighbour's claim arrives with the regulator's letter. The 2026 owner's guide to regularising unauthorised structures describes the process; it is longer and dearer than approval would have been.
Buyers of older landed houses should read that paragraph twice. The previous owner's "small extension" is a common and expensive discovery, and it is one reason our quotations carry a named provisional sum for what the survey finds.
The engineer who signs for the structure must never be the builder who profits from it. That independence is not a cost. It is the point.
How we work with the engineer
On a YCM Design & Build project the structural design and endorsement are carried out by an independent Professional Engineer appointed as Qualified Person, coordinated by our structural coordinator and architectural team. The engineer designs the party-wall support and piling method for attached houses, clears the temporary works, inspects the structure at each statutory stage, and signs the completion. We build what they endorse; we do not endorse what we build. Owners who wish to appoint their own PE are welcome to, and we will work with them exactly as we work with an appointed architect under Tender & Build.
Questions we are asked about A&A
Does hacking a non-load-bearing wall need approval?
A genuinely non-structural partition does not, but in older landed houses walls that look like partitions are sometimes carrying load. Have the engineer confirm before anyone swings a hammer. The cost of the confirmation is an hour; the cost of being wrong is a propped ceiling.
Can the builder submit the plans?
The builder can coordinate the submission, as we do, but the plans must be prepared and endorsed by the Qualified Person in their own name. A builder offering to "handle the BCA side" without naming the engineer is a builder to question.
How long does A&A approval take?
Two to four months for a typical landed A&A, URA and BCA combined, before works may start. Plans drawn inside the envelope from the beginning do not get redrawn, which is the main way that period is kept short.
- Building Control Act and Building Control Regulations: Qualified Person requirements, plan approval and permit to commence structural works.
- Urban Redevelopment Authority, Development Control guidelines for landed housing and envelope control.
- CVC Engineers, A&A Submission Singapore: When Renovations Need BCA Approval (2026), BCA Submission Service Singapore, PE Endorsement Cost in Singapore (2026) and How to Regularise an Unauthorised Building Structure.
- Professional Engineers Board Singapore, register of Professional Engineers.
Planning an attic, an extension, or an opening in the wall?
Send us the address and a sketch. We will tell you whether it is A&A, who must sign, and what the first month looks like.