The bathroom is where the most renovation dreams meet the most renovation rules — and where breaking one quietly can cost you a four-figure fine and a leak into your neighbour's ceiling. So before you redraw it, here are the three questions we're asked most, answered honestly, with the HDB reasoning behind each. The short version: you have less freedom in here than anywhere else in the flat, and there are good reasons why.

“Can I move my toilet bowl somewhere else?” — barely, and rarely worth it

People imagine the WC can slide to wherever suits the new layout. In practice it moves a little, if at all. Here's why: your toilet drains into a soil pipe and floor trap whose run, position and downward fall are built into the floor screed and tied to the sanitary stack. You aren't allowed to hack the structural floor slab to re-route drainage, and any change must still connect to the existing pipework without cutting new holes in the floor.

HDB does permit the WC and basin to swap or shift positions within the bathroom — but only where the floor slab stays untouched and everything still ties into the original pipes, and any plumbing work is done by a PUB-licensed plumber. Push the bowl far from its stack and you get a long, shallow drain run that clogs and smells. So the honest answer is: small adjustments, sometimes; a free relocation, no — the drainage was poured into the floor, and the floor is off-limits.

“It's a new BTO — can I hack the toilet and retile it?” — no, not for three years

This is the rule that catches the most new homeowners. For the first three years of a new BTO flat, you cannot hack or replace the wall and floor tiles in your bathrooms. It isn't HDB being fussy about taste — under those tiles is a waterproofing membrane that protects the unit below you, and it's under warranty for that period.

Hack it early and you don't just void the waterproofing warranty; you risk water seeping into your neighbour's home, and you expose yourself to a fine of up to $5,000 plus an order to reinstate the bathroom at your own cost.

The legal way to refresh it now

If you can't live with the developer tiles, the compliant move is to overlay — new tiles (or certain coatings) laid directly over the existing surface, without hacking, so the membrane stays intact. It raises the floor a few millimetres and, done well, looks like a full retile. Once the three years are up you can hack and retile properly — with a permit, and a mandatory water-retention test on the new waterproofing before anyone lays a tile.

The three-year wait isn't bureaucracy. It's the membrane between your shower and your neighbour's ceiling.

“Can I put in a bathtub?” — yes, but on HDB's terms

Good news, with conditions. A bathtub is allowed, but it can't become an excuse to break the rules that protect the slab:

  • It must stay within the original bathroom boundary — no extending the wet area to fit a bigger tub.
  • The floor slab and waterproofing layer must remain completely untouched beneath it.
  • The void under the tub cannot be packed solid with cement mortar — it has to stay an accessible space, with an inspection opening for maintenance and weep holes so any water can drain and be spotted.
  • The plumbing is a PUB-licensed plumber's job.

Done properly, the tub sits over a serviceable void, the waterproofing is undisturbed, and a future leak can be found and fixed — instead of being sealed inside a concrete coffin.

The pattern behind every rule

Notice the common thread: the floor slab and the waterproofing are sacred. Almost every bathroom restriction exists to protect the membrane that keeps water in your flat and out of the one below. Work with that and most of what you want is still possible. Fight it — hack the slab, drown a tub in mortar, retile a one-year-old BTO — and you're signing up for fines, leaks, and a very unhappy downstairs neighbour.

The bottom line

In the bathroom, ask what you can do, not just what you want. Move fixtures only as far as the existing drainage honestly allows, wait out the three years or overlay in the meantime, and build a bathtub that can be serviced. The rules are strict because the consequences run downhill.