The number, by extension type
You love where you live. You've just run out of room in it. That's how most extension conversations start, and it's why the first number people ask for is usually the wrong one. An extension isn't priced like a renovation, because you're not refreshing space that already exists. You're building new structure: foundations, a frame, a roof, drainage, and a council approval in front of all of it.
Published 2026 guides split the cost mainly by whether the extension stays on the ground or adds a floor:
| Extension type | Typical rate | Typical total |
|---|---|---|
| Ground-floor extension | RM180 to RM450 per sq ft, from a basic utility extension to complex semi-D and bungalow work | RM90,000 to RM180,000 for a typical Klang Valley landed home |
| Kitchen extension | Within the same range | RM55,000 to RM140,000 |
| Second-storey extension | RM400 to RM520 per sq ft | RM200,000 to RM350,000 for a new floor over the existing one |
These are indicative market ranges, not a quote. They come from Malaysian sources published in 2026 and listed at the bottom of this page. Plan your renovation and we'll give you a scoped figure instead of a range.
Why does a second storey cost more per square foot than the ground floor? Because the house underneath often can't carry it as built. The existing columns and foundations frequently need strengthening before a new floor can go on top, and that work is invisible in the finished room but very visible in the quote. As a rule of thumb from one guide, a quote under about RM250 per sq ft for a finished extension has probably left out the foundations or the authority fees.
The spread is wide for the same reasons it's wide on any renovation: structure, roofing, foundations, drainage, approval, materials, site access and the condition of the existing house all move the number. A shell with no interior fit-out sits at the bottom of the range; a finished, move-in-ready room sits at the top. For context, Duotone's own projects, from partial works to full design and build, typically run from around RM30,000 to RM500,000 and above.
Setbacks: how close to the boundary you can actually build
Before any of those numbers matter, there's a harder question: how much can you legally add at all? Every council sets its own setback rules, DBKL, MBPJ, MBSJ, MBSA, MBDK and the rest, and they often depend on which floor you're building and how wide your back lane is.
Two examples show how specific the rules get. In Kuala Lumpur, DBKL's guidelines let a terrace house build right up to the rear boundary where there's a back lane of 3m or more. In Subang Jaya, MBSJ lets every floor extend to the edge of the lot where the gap behind is over 20 feet, but where it's 15 to 20 feet, only the ground floor can, and upper floors must stay 3m back from the lane's centre line. Side extensions on corner and end lots have limits of their own.
So don't take your neighbour's extension as proof of what's allowed on your lot. The rules may have changed, or they may have had a waiver. Confirm your own council's rules before a design goes anywhere near a quotation.
Approval: what it actually involves
An extension almost always needs the council's written permission first. Under the Street, Drainage and Building Act 1974, adding to a building in a way that involves new foundations, or new or bigger structure or roof, counts as erecting a building, and the plans have to be submitted and approved under the Act and its Uniform Building By-Laws 1984. That covers almost every real extension.
Guides put approval at two to six months before a single brick is laid. The Act gives the council three calendar months to decide on a complete submission, and if the council asks for changes, the clock restarts from the resubmission. An incomplete or unclear submission is the most common reason this stage drags, so a properly prepared submission, the first time, is the biggest lever you have over the timeline. Building without approval isn't a shortcut: it can mean a fine of up to RM50,000 and an order to demolish.
Living through it
A ground-floor extension is disruptive but contained; the rest of the house usually stays liveable. A second storey is a different order of disruption. The roof stays open for weeks, so dust, noise and weather are constant while the work is underway. Many owners move out, or stay with family, for the roughest stretch, even when the ground floor technically remains usable.
How we handle the approval stage
We submit the plans, track the application and handle revisions if the council asks for them, so approval is something we manage rather than something you wait on. Setbacks and structural limits are checked before a design is presented, not after, so the plan you approve is one the council can realistically approve too.
See our house extension service page for completed projects, or our renovation approval guide for how the same process works across the Klang Valley's councils.
