What plumbing work needs HDB approval?

Does an HDB plumbing renovation need a permit?

HDB's guidelines for water and sanitary plumbing works say the works on that page, from pipes and sinks to toilet pans and bathtubs, do not require a permit from HDB. They are still subject to HDB's technical terms and conditions.

HDB makes you, the flat owner, responsible for making sure your contractor follows its guidelines. Under HDB's permit rules, works that need no permit but do not follow those guidelines are unauthorised works, and HDB will require you to discontinue, correct or remove them and reinstate the flat.

Tiling is different. HDB's building works guidelines list replacing floor finishes such as ceramic or homogeneous tiles as permit work. If your job includes tiling or other building works, run it through the renovation permit checker before you sign a contract.

Pipe works

You can replace an existing PVC water pipe with a copper or stainless steel one, but HDB says it must comply with PUB requirements. Installing, fixing, altering, replacing or removing any water pipe, discharge pipe or stack, or ventilating pipe or stack must be done by a PUB Licensed Plumber. To weigh up materials, see PPR, copper or stainless steel pipes.

Concealing pipes in floor finishes or walls has stricter terms. HDB says the floor slab and walls must not be tampered with, the work must comply with PUB requirements and a PUB Licensed Plumber must do it. HDB discourages it, because if not done properly it may cause water leakage to the unit below.

To box pipes in instead, HDB allows service ducts or piping, but not gas pipes, to be enclosed with lightweight non-combustible materials, with a removable access opening of at least 600mm x 600mm.

Toilets, sinks and bathtubs

For HDB sanitary works, start with the toilet pan. HDB says installing, fixing, replacing or removing a toilet pan, and sealing the discharge pipe, must be done by a PUB Licensed Plumber. If you want to relocate a toilet in an HDB flat, check HDB's conditions with your plumber first.

HDB's other conditions depend on the fixture.

A bathtub also needs an inspection opening, and HDB does not allow a toilet to be extended to fit a long bath. Cost depends on the job; see the toilet bowl replacement cost guide.

Bathroom floor and wall finishes

HDB says toilet floor and wall finishes provided by HDB or the developer must not be replaced for 3 years from the completion date of the block, because of the waterproofing membrane laid under them. New floor finishes may be laid over the existing ones.

Under HDB's building works guidelines, laying finishes over existing ones with adhesive only needs no permit, on conditions that include only 1 layer of existing finishes (including cement screed), a thickness including adhesive of no more than 13mm and no tampering with the floor trap. After the first 3 years, replacing toilet floor finishes needs a permit, with waterproofing and no more than 50mm of finishes and screed in total.

Tile hacking is restricted work. HDB lists removing wall or floor finishes and cutting tiles as noisy works allowed only from 9am to 5pm on weekdays, never on public holidays or the eves of listed festivals such as Chinese New Year and Deepavali. For more, see HDB floor tile rules.

Who does the work

PUB says all regulated water service and sanitary plumbing works must be done by a PUB Licensed Plumber, except simple plumbing works that a handyman may do. These include replacing or removing any tap or mixer; installing, replacing or removing any washbasin, sink, bathtub or shower tray; and clearing any blockage in any floor trap, water closet or sanitary appliance. The pipe items are narrow, such as any pipe between a stop valve and an instantaneous water heater. Repairing or replacing any other water pipe, concealed or exposed, and installing, changing or relocating a toilet bowl are not on the list.

HDB requires you to engage only contractors from its Directory of Renovation Contractors for renovation. You can find a licensed plumber through PUB's online listings, the Singapore Plumbing Society or your Town Council. See what needs a licensed plumber for more.

Before you start

• Check which works need a permit in the HDB renovation permit guide.
• Plan noisy works within HDB's hours: general renovations 9am to 6pm on weekdays and Saturdays, restricted works 9am to 5pm on weekdays only, and none on Sundays and public holidays.
• Give neighbours within a radius of 2 units a written notice at least 5 days in advance, as HDB asks.
• If your Town Council does not provide a debris removal service, HDB says your contractor must dispose of the debris at a site approved by the National Environment Agency.
• Ask plumbers to set out the work in writing.

Questions