Short answer: Qanvast estimates about $5,000 to $12,000 per bathroom in a new 3 or 4-room BTO flat, including basic fittings. Resale bathrooms usually cost more, because Qanvast notes the waterproofing layer and the wall and floor tiles often have to be redone entirely. Multiply by the number of bathrooms in your flat.

Bathroom renovation cost at a glance

Estimates differ by source and scope:

  • Qanvast (2024), new BTO bathroom: basic works (basic carpentry and fittings installation, flooring untouched) about $3,000 to $5,000; extensive works (tile overlays and custom changes such as shower niches) about $6,000 to $9,000; fittings (basic shower screen, water heater, basin and tap, toilet bowl, shower set, ceiling light) about $2,000 to $3,000.
  • Qanvast (2024), general guide: about $3,000 to $3,200 per bathroom for basic works and $5,000 to $5,900 for more extensive works, with fittings and appliances from about $2,000 on top.
  • SmartCalculator (2026): about $5,300 for all bathrooms in a 4-room BTO standard scope, and about $9,000 in its 4-room resale worked example.

Qanvast also advises multiplying by at least two for flats with more than one bathroom. All of these are estimates, not quotes.

Why new BTO bathrooms cost less

New HDB flats come with a 3-year restriction on removing the wall and floor finishes in bathrooms and toilets, counted from completion of the block. That keeps the waterproofing intact while it settles, and it also limits what you can spend in the early years. Most BTO bathroom work is therefore:

  • Fitting a vanity, mirror cabinet and shelves.
  • Adding a shower screen, water heater and new fittings.
  • Overlaying tiles, where allowed.
  • Lighting and an exhaust fan.

For overlays laid with adhesive only, HDB says there should be only one existing layer of floor finish, the new layer including adhesive must not exceed 13mm, and the floor trap must not be tampered with.

Why resale bathrooms cost more

In an older flat, tiles may be hollow, grout stained and the waterproofing past its best. Replacing finishes means hacking, new waterproofing and new tiles. HDB's conditions for replacing bathroom floor finishes include:

  • A permit is required.
  • Total thickness of finishes and screed must not exceed 50mm.
  • Pre-packed waterproofing screed and a waterproofing membrane must be used, with the membrane upturned at least 150mm against the walls, kerbs and pipes.
  • UPVC floor trap grating with a long collar must be used at floor traps.

Hacking and tile cutting are noisy works, limited to 9am to 5pm on weekdays excluding public holidays. Water and sanitary plumbing must be done by a PUB licensed plumber. See our resale HDB renovation cost guide for the wider budget.

What goes into the bill

  • Hacking and disposal (resale): removing old tiles, fittings and sometimes the bathtub.
  • Waterproofing and screed: non-negotiable when finishes are replaced.
  • Tiles and laying: larger tiles mean fewer grout lines. Qanvast notes anti-slip ratings run from R9 to R13, with higher ratings less slippery but often harder to clean. See our tiles guide.
  • Sanitaryware: toilet bowl, basin and taps. Our sanitaryware guide compares types.
  • Shower screen: from a simple fixed panel to framed or frameless sliding glass. See shower screens.
  • Vanity and storage: compare options in our bathroom vanities guide.
  • Water heater, exhaust fan and lighting.
  • Plumbing changes: moving the toilet or basin adds cost quickly.

HDB and PUB rules that shape the design

  • Kerbs: a cement mortar kerb up to 100mm high and 100mm wide needs no permit.
  • Enlarging a bathroom: only after the first 3 years, with a permit. The extension must be no more than 600mm wide and 0.6 square metres in area, can only be a dry area (for example a basin or shelves), and must not enclose the gas riser or its branch pipe.
  • Bathroom vent: replacing it needs a permit, and glass louvres must be at least 6mm thick, wire-glass type, with an aluminium U-channel safety cleat on each louvre.
  • Water efficiency: PUB only allows fittings rated 2 ticks or above to be supplied and installed. For 2 ticks, shower taps and mixers must be above 5 and up to 7 litres per minute, basin taps above 2 and up to 4 litres per minute, and dual-flush cisterns above 3.5 and up to 4.0 litres on full flush. Check the label when you buy.

Overlay or hack?

Overlay suits sound, level tiles you simply dislike. It is quicker and avoids hacking, but it must stay within HDB's 13mm limit and the existing waterproofing stays as it is.

Hack and redo suits bathrooms with leaks, hollow tiles, an earlier overlay or old waterproofing. It costs more but resets the bathroom for the long term.

If you are unsure, ask your contractor to tap-test the tiles and check for leaks before deciding.

How to keep the bill under control

  1. Keep the layout. Leaving the toilet, basin and shower where they are avoids most plumbing costs.
  2. Choose one feature. A statement tile on one wall or a niche looks deliberate and costs less than premium finishes everywhere.
  3. Pick finishes for humidity. Qanvast advises avoiding limewash and wallpaper in bathrooms, because moisture can cause cracking, peeling and mould, and suggests an exhaust fan to reduce moisture.
  4. Buy fittings to a list. Agree who supplies what, so nothing is double-counted.
  5. Quote on the same scope. It is the only way to compare quotations fairly. Planning the kitchen too? See our kitchen renovation cost guide.

How JIAHOME helps

We design bathrooms with your layout, finishes and fittings fixed before you collect quotes, and our quotation lists every item without prices so any contractor can price the same work. Book a free first consultation via contact us.

*This article is general information, not financial advice. All prices are third-party estimates; get itemised quotes for your own bathrooms.*

Last updated 14 October 2026