5 Things HDB Won't Let You Do (And What Happens If You Do Them Anyway)

Most HDB renovation rules are about process: get a permit, use a contractor from HDB's Directory of Renovation Contractors. These five are different. They're things HDB won't approve at all, whatever contractor you use. Getting one wrong doesn't mean a warning letter. HDB can order you to reinstate the flat to its original condition at your own cost, and a breach of the Renovation Control Rules carries a fine of up to $5,000 on conviction.

No hacking or removal of reinforced concrete. Walls, columns, beams and slabs are structural and off-limits, whoever tells you otherwise. Even non-load-bearing walls need HDB's written approval before a single tile comes off.

The household shelter stays as built. Its reinforced walls, floor slab, ceiling and steel door can't be hacked, modified or tiled on the inside, and the door notice can't be painted over. It's a civil defence shelter, not a spare room waiting to be opened up.

Gas pipes can't be hidden. HDB doesn't allow a gas pipe inside a false ceiling or buried in the floor screed, and the kitchen weephole that warns you of a leak in the sanitary duct can't be sealed behind carpentry.

Your main door stays fire-rated if it opens onto a fire escape route such as a staircase or lift lobby. The replacement needs a permit, has to be half-hour fire-rated with a self-closing frame and an accreditor's label, and a digital lock on it has to be certified too.

Fish tanks are capped at 600kg per room on a rack or cabinet, counting the water, sand and accessories. Anything bigger, or a pond on the floor, needs the HDB Branch's approval first. It's a load limit on the slab, not a taste thing.

Reinstatement means undoing completed work: hacking out what was just built, at your cost, on top of whatever it cost to build it wrongly in the first place. It's also the kind of thing that stalls a renovation timeline by weeks while the correction is inspected and approved. None of these five rules are unusual or unreasonable once you know them; the expensive mistake is finding out about them after the work is done rather than before it started.

These five are the ones that surprise people most, but they're not the whole list. HDB publishes the full guidelines, linked below. If you're planning a renovation and want the fuller picture before you commit to a scope, that's exactly what we walk through at the start of a design proposal.