Requirements and restrictions when installing a bathtub in your HDB flat bathroom

Design: Fuse Concept

Do you live in a HDB flat and really want a bathtub?  Good news! Here's what you can do — make space for one by enlarging the existing bathroom, or combining two adjacent bathrooms to get a bigger one. Designer Annie Tan of The Interarch Design recommends having at least 66sqf for the whole bathroom, if you install a bathtub in addition to a standing shower. Also, take note that you can only do alterations to your bathroom three years after the completion date of the block, and you still need to obtain a permit from the HDB.

Enjoying a soak in a tub isn’t impossible, as long as you follow the regulations stipulated by the HDB during your bathroom renovations.


Consider smaller types of tubs, such as a soak tub, to still get a spa-style feel in a smaller space (interior designer here).

+ If you extend your bathroom into the living area, the maximum width and area of extension must not exceed 60cm and 6.5sqf respectively.

+ The new part of the bathroom (which was previously part of the living area) can only be used as a “dry area” (e.g installation of washbasin or shelves). This means that both the bathtub and shower area have to fit within the footprint of the original bathroom.

+ The extension cannot be done around the flat’s gas riser and its branch pipe.

+ If you are doing hacking works and changing the floor finishes, pre-packed waterproofing screed and waterproofing membrane is to be used and the total thickness of finishes and screed must not exceed 5cm.

+ The total weight of your bathtub, including the supporting structure, shouldn't weight more than 150kg. This is so that the structural integrity and safety of the building isn't compromised. Verify especially the weight if you are considering heavy models like freestanding clawfoot cast iron tubs.

+ There has to be a void underneath the tub. Do not fill up the space underneath with cement mortar or other materials to support the tub.

+ The floor slab must not be tampered with at all — no raising or lowering it to accommodate your built-in bathtub.


Be inspired by more beautiful bathrooms here!