There is no HDB permit. Your constraints come from your own development's by-laws, and they are often stricter.
The rules that govern a condo renovation are written by the development itself, which is why two projects across the road from each other can face very different conditions.
The MCST is the approving body, and its by-laws bind you
A condominium is governed by its management corporation under the Building Maintenance and Strata Management Act, and the by-laws it passes apply to you whether or not you attended the meeting that passed them. Expect to submit drawings for approval, place a refundable renovation deposit, book the service lift, register your contractor, and work within permitted hours that are frequently tighter than HDB's. Some developments restrict wet works or flooring changes outright. All of this should be confirmed before the design is finalised, because it affects both what is possible and how long it takes.
You cannot touch common property — and the boundary surprises people
External windows and facade, the main entrance door in some developments, corridors, external walls and anything outside your lot are common property, and altering them is not yours to authorise. Work that increases the development's total gross floor area — roofing over a private enclosed space, or slabbing over a void in a double-volume unit — needs a 90% resolution of the management corporation, and may also require URA and BCA approval on top. These are the proposals that quietly die at approval stage, so they are worth testing early rather than designing around for months.
Structural work still needs a Qualified Person
Being inside your own unit does not exempt structural alteration from the Building Control regime. Removing or penetrating a structural element requires a Qualified Person — a registered architect or professional engineer — to submit plans to BCA, exactly as in a landed house. An interior designer cannot make that submission. If your concept depends on opening up a structural wall, that consultant needs to be in the conversation from the beginning, not appointed once the drawings are done.
Waterproofing is where the real financial risk sits
In a stacked building, a failed wet area does not damage your flat — it damages the one below, and the liability is yours. This is why we treat waterproofing in a condo as a specification issue rather than a line item to trim: proper membrane, proper upturns, proper falls, and a water test before anything is tiled over. The same logic applies to any relocation of drainage, which is constrained by the existing stack position far more than most homeowners expect.
Ceiling height is the hidden design constraint
Condo units often have generous floor-to-floor height on paper but real constraints in practice — aircon trunking, structural beams, sprinkler heads in newer developments, and existing false ceilings hiding all of it. Where the ceiling can and cannot drop determines lighting design, aircon positions and whether a feature bulkhead is possible. It is worth opening a small section of existing ceiling early rather than designing on an assumption.
Approvals & rules
Who approves the work.
Approving bodyManagement corporation (MCST), plus BCA and URA where applicable
Submit drawings to the MCST for approval; expect a refundable renovation deposit and contractor registration.
By-laws made under the Building Maintenance and Strata Management Act bind all subsidiary proprietors.
Permitted hours, lift booking and access are set by your development and are often stricter than HDB's.
Common property — facade, external windows, corridors — cannot be altered by a unit owner.
Work increasing the development's total gross floor area needs a 90% resolution, and may need URA and BCA approval.
Structural alteration requires a Qualified Person to submit plans to BCA.
Rules and timeframes change. These were checked against the linked official pages on the date shown — please confirm anything critical with the relevant authority.
What drives the cost
Where the money actually goes.
Listed roughly largest first, for this property type specifically. A reliable figure still needs a site assessment — this is what to expect it to be made of.
We do not quote a fixed package price, because two homes of the same size rarely need the same works.
01
Extent of wet-area work, and waterproofing specification
02
Carpentry quantity and finish level, which in condos tends to run higher
03
Whether the ceiling is being reworked, and what is found above it
04
Aircon: relocating fan coil units and drainage is often more involved than expected
Consultant fees where a Qualified Person is required
Common mistakes on this property type
Designing before reading your development's by-laws and renovation conditions
Assuming the entrance door or windows are yours to change
Trimming the waterproofing specification, where the downside is the unit below
Planning drainage moves without confirming the existing stack position
Underestimating approval and lift-booking lead time, then compressing the build to compensate
How long it takes
Timeline, honestly.
Typically around 10 to 16 weeks on site, but MCST approval and lift booking can add weeks before work starts. Build that into the programme rather than the contingency.
Delays most often come from late material selections or changes requested mid-build, not from the site work itself.
Questions worth asking
What we'll ask you first.
01
What do your development's renovation by-laws and permitted hours actually say?
02
What is the renovation deposit, and what conditions release it?
03
Does the concept require touching anything structural or any common property?
04
Where is the existing drainage stack, and is it being moved?
05
What is above the existing false ceiling?
Not sure of the answers yet? That is fine — working them out is part of the first conversation. For the wider picture, the renovation guide covers permits, hours, materials and costs in detail.
Start with clarity
Ready to talk through your condo renovation?
Tell us your property type, timeline and the work you have in mind. We'll help you decide the next practical step.
