A 4 room BTO renovation is reported to average S$51,000 to S$61,800, inside an observed spread of S$27,000 to S$145,000. That spread is the story of this flat type.
A 4 room BTO renovation is reported to average S$51,000 to S$61,800 inside an observed S$27,000 to S$145,000 range. The 4-room BTO flat has the widest published spread of any type, and almost all of it is scope rather than market.
01 PERMIT
Hacking always
needs one
All demolition and hacking of walls, partial or complete, needs HDB’s prior written approval before anything starts.
hdb.gov.sg · read 2026-08-31
02 HOURS
Mon to Fri
9am to 5pm
Restricted works only. General works such as painting and screed run Monday to Saturday until 6pm.
hdb.gov.sg · read 2026-08-31
03 DEADLINE
3 months for
a new block
From the date the permit is granted. Existing blocks get 1 month.
hdb.gov.sg · read 2026-08-31
Around 90 square metres, three bedrooms and a living area. The work packages are the same eight every flat gets, but the quantities are larger and the carpentry run is the longest of the common types.
Naming them is the only way two quotes ever become comparable. In a flat this size the difference between two scopes is easily the price of a small car.
Two publishers, both dated. One reports an average of S$51,000 to S$61,800. The observed range around that average runs from S$27,000 to S$145,000.
| Item | Reported range |
|---|---|
| 3-room BTO | S$25k to 50k |
| 4-room BTO | S$51k to 62k |
| 5-room BTO | S$40k to 115k |
Ranges as published by each source, not averaged together. The 4-room row carries the widest observed spread of any flat type.
Sources interiordiary.com.sg 2026-08-31qanvast.com 2026-08-31moneysmart.sg 2026-08-31
A five-fold spread does not mean the market is chaotic. It means the same flat can be finished simply or extensively, and the published average sits between two very different jobs.
The recurring question is what bedroom three becomes. A study, a walk-in wardrobe, a nursery or a room left alone, and the answer changes the carpentry measure before anything is ordered.
We walk the flat after key collection, measure every run, and write down what you want changed and what HDB will let you change.
Your contractor files the electronic application. Wall demolition needs the flat’s floor plan submitted with it.
Demolition, tiling and anything touching the bathroom happen first, inside the restricted-hours window.
Kitchen and wardrobe carpentry is fabricated to a fixed specification, then installed, then painted.
The second recurring question is the service yard. Absorbing it into the kitchen buys work surface and loses the only place in the flat designed to be wet and ugly.
The ideas worth the money in this flat type are the ones that survive ten years and a change of household, not the ones that photograph well on handover day.
Every one of those is a scope decision with a number attached. That is the difference between an idea and a mood board.
Structural walls, beams and columns are never removable. In many 4-room layouts the wall people most want gone, between the kitchen and the living area, is the one most likely to be structural.
Get the classification confirmed from the floor plan before quoting. A wall that turns out to be structural after the deposit is a design change nobody budgeted.
The HDB renovation guidelines treat this flat no differently from a smaller one, which surprises people. More rooms does not mean more latitude, it means more walls to classify before anyone quotes.
Only a firm in the Housing & Development Board’s Directory of Renovation Contractors, under the Housing and Development (Renovation Control) Rules 2006. The check is public and takes a minute.
The requirement covers works needing no separate approval, and the penalty attaches to the flat owner as well as the contractor.
The same register governs every renovation contractor Singapore homeowners can lawfully engage, whether they sell a bto renovation package or price the trades line by line. Check it before the deposit either way.
The HDB renovation permit is filed by your contractor before anything starts. Three months in a newly completed block, counted from the day it is granted.
General renovation works run Monday to Saturday, 9am to 6pm. Restricted renovation works, meaning demolition, removing finishes and cutting tiles, run Monday to Friday, 9am to 5pm only.
Sources MyNiceHome by HDB 2026-08-31
They are also banned on five named festival eves. With two bathrooms and a longer hacking list, a 4-room flat feels that constraint more than a smaller one does.
If you kept the Optional Component Scheme flooring, the quote should not be pricing new floors. If you opted out, removal and making good belong in it as named lines.
One documented project paid this for a whole-flat flooring package. In a 90 square metre flat the removal cost scales with the area you are removing.
This is also where a resale flat renovation and a new-flat fit-out stop looking different. Once you opt out, you too have a floor to remove before you have a floor to lay.
Tell us the flat type and when you collect keys. You get a scope discussion and an indicative cost band within one working day.
or email hello@btorenovation.sg
Across a larger floor area those figures scale. It is the line most comparisons omit, and it is a large part of why two quotes for the same 4-room flat diverge.
Priced per foot run, and this flat has the longest run of the common types. Three bedrooms, a kitchen and usually a television console add up before anyone discusses a rate.
Ask what the carcass is and get it in writing. Plywood, moisture-resistant plywood, blockboard and MDF take the same laminate and behave very differently once water reaches them.
Carpentry Singapore-wide is quoted this way, so the comparison method travels. Ask two firms for run length and carcass and you can read their numbers against each other in minutes.
The run is long enough that layout genuinely matters. An L-shape against a galley changes both the carpentry measure and where the plumbing has to go.
Moving a plumbing point costs more than the cabinet above it, because it means opening the floor and re-waterproofing. Settle the sink position before anything is ordered.
A kitchen renovation in Singapore is priced on run length and wet works in exactly the way this flat exaggerates. The longer the run, the more the layout decision is worth getting right first time.
Most 4-room layouts have two, which doubles the waterproofing decision rather than repeating it cheaply.
Overlay keeps the membrane intact and keeps the number down. Hacking to the screed means re-waterproofing, re-screeding and making good, in both rooms.
A toilet renovation in Singapore is really a waterproofing decision wearing tiles. With two bathrooms you make that decision twice, and the second one is not cheaper for having made the first.
Electrical work must be done by a worker holding the relevant Energy Market Authority licence, separate from the firm’s registration. Point counts run high in a three-bedroom flat.
Agree the point count room by room before first fix. Adding a socket after the walls close is a variation, not an afterthought.
Overlay is faster and avoids making good, at the cost of raising the floor level. Across 90 square metres that saving is meaningful.
Neither is right in general. The decision is about whether the existing floor is in your way or merely not to your taste.
Coverage and preparation, not the brand on the tin. A 4-room flat has enough wall area that one extra coat is a real line rather than a rounding error.
Ask how many coats and what surface preparation is included. Those two answers explain most of the difference between painting lines that otherwise look identical.
Each stage blocks the next, and in a three-bedroom flat there is simply more of each stage to get through.
Longer than a 3-room and inside the same permit window, which is the tension. The window is the outside date, not the estimate.
Ask for lead time and install time separately. Carpentry for three bedrooms is fabricated off site, and those weeks are real weeks that a headline duration usually hides.
Build the renovation timeline backwards from the permit expiry rather than forwards from the start date. It is the only version of the schedule that has to be true.
Tell us the flat type and when you collect keys. You get a scope discussion and an indicative cost band within one working day.
or email hello@btorenovation.sg
Four things, and in a flat with this much carpentry the second and third matter most.
A quote produced without a site measure is a guess. In this flat type a guess is the difference between the bottom and the top of that observed spread.
Because no two firms scope the same job from the same brief. One assumes bedroom three keeps a standard wardrobe, another prices a full walk-in.
Normalise the scope and the numbers converge fast. Most of what looks like a price difference in a 4-room quote is a carpentry measure nobody wrote down.
That is worth remembering when an hdb renovation loan is sized against the higher quote. You may be borrowing against somebody else’s assumption about bedroom three.
Tie payments to stages you can walk into and inspect, never to dates.
Ordering carpentry before the site measure, in the flat type where carpentry is the largest line. Deciding bedroom three’s purpose after the wardrobes are built.
And treating two bathrooms as one decision made twice. They are two waterproofing jobs, two schedules and two chances to get the falls wrong.
The last one is collecting hdb renovation ideas for months and never converting any of them into a written scope. Inspiration is free and a measured scope is what a contractor can actually price.
Every figure on this page names its publisher and the date it was read. A band with no source behind it is left off the page rather than filled in from memory.
Every number carries a named publisher and its publication date. Regulatory claims cite HDB directly with the date the page was read.
Where two publishers disagree, both figures appear. The HDB renovation rules and costs hub applies the same method across the site.
No licence number, no accreditation, no review, no rating and no photograph captioned as our own completed project. None exists for BTO Renovation SG.
Every interior image here is a generated illustration and says so. These are the checks to run on any contractor, including us and including whatever the register says about them.
Tell us the BTO project, that it is a 4-room, when you collect keys and what you decided about the Optional Component Scheme.
You get a reply within one working day with a scope discussion and an indicative cost band for this flat type, narrower than the published spread because it will be about your flat.
Checked against primary sources · updated 2026-09-01
