The HDB renovation permit, explained

You do not apply for an HDB renovation permit yourself. A contractor listed in HDB's Directory of Renovation Contractors (DRC) submits it electronically on your behalf, with the flat's floor plan marked up to show the work. Hacking walls and replacing floor or bathroom finishes need a permit. A fine of up to S$5,000 applies on conviction for breaching the rules.

Everything below is taken from HDB's own renovation pages, linked at each point. HDB revises its guidelines from time to time and says that any approval is subject to the prevailing terms, so treat this page as correct as at 2 October 2026 and let your contractor confirm anything your plans depend on. Where HDB does not publish something, such as how long approval takes, we say so rather than repeat a figure from a renovation blog.

Who applies: your contractor, on your behalf

HDB is explicit about the mechanics on its application for a renovation permit page. You must engage a contractor listed in the Directory of Renovation Contractors for all renovation in your flat. You then authorise that contractor to submit an electronic renovation application on your behalf, and the contractor attaches a copy of an acknowledgement form signed by you. HDB sends you an SMS when it receives the submission, and you can view and check the permit once it is granted.

So when people search for an "HDB renovation permit form", the honest answer is that there is no separate owner's form to fill in and post. Your two practical jobs are to sign the acknowledgement form and to make sure your contractor has the flat's floor plan. HDB states that it evaluates certain types of renovation, such as demolition of walls, and that renovation contractors are to submit the flat's floor plan showing the proposed work together with the electronic application.

Being on the DRC is itself a legal requirement, not a quality badge. Under Rule 6 of the Housing and Development (Renovation Control) Rules 2006, only DRC contractors may carry out renovation in HDB flats or advertise that they can. HDB is equally clear that it does not endorse or guarantee the quality of their work: the contract is a private one between you and the contractor. You can search the directory, and HDB's list of BCA approved window contractors, through the e-Service linked from HDB's looking for renovation contractors page. HDB also runs a demerit points system for DRC contractors: 24 demerit points within 24 months leads to a one-year suspension.

A few trades sit outside the general contractor, and HDB names the licence each one needs:

• Water service and sanitary works: a PUB Licensed Plumber. A handyman without a PUB licence may still do simple plumbing work.
• Gas service works: an Energy Market Authority (EMA) licensed gas service worker.
• Windows: a BCA approved window contractor listed with HDB.
• Electrical installation: an EMA licensed electrical worker. Certain electrical works need a separate Electrical or Air-Conditioner Installation Permit, which your Licensed Electrical Worker may apply for on your behalf.

For a brand new flat there is one more prerequisite that catches people out: HDB will not grant a renovation permit until you have opened a utilities account for water and electricity with SP Services.

Which works need a permit, and which do not

HDB's renovation guidelines are organised as tables: each type of work, whether a permit is needed, and the conditions attached. The rows below are a selection from HDB's building works guidelines and the related pages for windows, plumbing and air-conditioning, chosen because they are the items most renovations involve. They are not the complete list.

The "No" rows deserve a careful reading, because "no permit" does not mean "unregulated". HDB states that work which does not need a permit must still follow the guidelines for it, and that work which does not comply is treated as unauthorised, with the same consequences as skipping a permit. Where an item is not in the guidelines at all, or where your measurements differ from the ones HDB states, HDB says you must seek its approval before starting.

HDB also advises checking for renovation guidelines specific to your flat on the MyHDB page. Some precincts, DBSS flats among them, have their own rules on top of the general ones, and flats handed over from 1 July 2007 have approved designs for items such as grilles.

Hacking walls: what HDB allows, and what it never allows

This is the part most searches for an "HDB hacking permit" are really about. HDB's important information on renovations page puts it without qualification: all demolition and hacking of walls, partial or complete, requires HDB's prior written approval. The reason given is structural integrity and public safety. HDB also tells owners not to instruct workers, or anyone else, to carry out demolition or hacking that HDB has not approved in writing.

The conditions on approved demolition of internal partitions are specific:

• Existing reinforced concrete structures must not be tampered with during the works.
• Block, brick, drywall or Ferrolite walls may be removed up to the underside of the beam or slab only.
• Block and brick walls are demolished from the top down; drywall and Ferrolite walls in full, joint to joint.
• If steel bars are discovered during demolition, the works must stop and HDB must be informed immediately.
• Where non-load-bearing reinforced concrete elements are removed, a Professional Engineer supervises, receives a copy of the approved plan and conditions, and ensures the affected structure is properly repaired. HDB tells you and your contractor when a PE is needed once it receives the application.

Then there is the list of things HDB will not approve at all. Its examples of disallowed building works begin with the hacking and removal of structural members: reinforced concrete walls, columns, beams, slabs, and staircases within executive maisonettes. The household shelter is in the same category. HDB describes it as a civil defence shelter with reinforced walls, floor slab, ceiling and a steel door, and none of those may be tampered with during renovation. Other disallowed items include loading the floor slab with more than 150kg per square metre, raising the floor by more than the allowed 50mm with concrete, covering over void areas in maisonettes or loft units, and plastering ceilings.

Which walls in your particular flat are structural is not something to judge by tapping on them. HDB evaluates the proposed demolition against the marked-up floor plan your contractor submits, and that evaluation is the point of the permit. Our HDB floor plan guide covers what the plan shows and where it stops. If a contractor offers to remove a wall before HDB has approved it, that is the moment to find a different contractor.

Bathrooms and kitchens: the 3-year rule and waterproofing

Newly built flats carry a 3-year restriction on removing bathroom and toilet wall and floor finishes. The reason HDB gives is the waterproofing membrane laid on the cement screed under the toilet floor, which stops water leaking into the ceiling of the flat below. The detail that many summaries get wrong is the start date. HDB counts the 3 years from the completion date of the block, not from the day you collected your keys. If your block was completed some months before you moved in, part of the restriction may already have run.

During those 3 years you are not stuck with the original look. HDB allows new toilet floor finishes to be laid over the existing ones using adhesives, without a permit, provided there is only one existing layer underneath and the new layer including adhesive is no more than 13mm thick.

After the 3 years, replacing bathroom finishes needs a permit, and HDB's technical conditions apply:

• Pre-packed waterproofing screed and a waterproofing membrane before the new floor finishes.
• The membrane upturned at least 150mm against the walls, kerbs and pipes.
• Floor finishes and screed no more than 50mm thick in total; wall finishes including plaster no more than 25mm.
• A UPVC floor trap grating with a long collar at the floor traps.
• A water test on the bathroom once the new floor finishes are complete.

Enlarging a bathroom is possible after the same 3-year period, with a permit, but only by up to 600mm in width and 0.6 square metres in area, and the extension may be used only as a dry area, for a wash basin or shelves for example. Kitchens follow a related rule: pre-packed waterproofing screed before new floor finishes, and a membrane around the sanitary stacks within a 400mm radius. Where a kitchen has an enclosed sanitary duct with a weephole, HDB asks that the weephole is not sealed or blocked by carpentry, because it is there to warn you of a leak.

Windows, gas and air-conditioning

Windows. HDB's window works guidelines require a BCA approved window contractor listed in HDB's directory for all window installation and replacement, and set out construction requirements down to the grade of the stainless steel friction stays. For flats handed over from 1 July 2007, replacement windows must match the colour scheme, proportion and type of the originals. HDB lists replacing full-height, three-quarter-height and bay windows among its disallowed works, and safety barriers integrated with those windows may not be removed unless damaged. Window-only works have their own, shorter, completion deadline, covered below.

Gas. HDB's plumbing and gas guidelines say the listed water, sanitary and gas works do not need an HDB permit, but carry technical conditions. Gas riser pipes must not be tampered with, gas pipes must not be embedded in common partition walls, and spaces with gas pipes may not be converted into bedrooms. Gas pipe alterations are carried out by City Energy or a licensed gas service worker. Gas pipes also may not be embedded in floor screed or enclosed within a false ceiling.

Air-conditioning. HDB's air-conditioner installation guidelines say no HDB permit is needed where the flat already has the higher 40-amp electrical loading, which applies to blocks completed on or after 1 January 1994 and to blocks that have been through the Main Upgrading Programme or Home Improvement Programme. The installer must be BCA trained, piping must run internally, condensing units may not be placed along the common corridor, and you submit an installation report to the HDB Branch managing your flat within 14 days. No holes may be hacked through reinforced concrete for the piping.

Renovation hours and deadlines

HDB sets both the hours in a day and the length of the whole job. These come from the general terms and conditions on its important information on renovations page.

The completion deadline is the one to plan around. A month runs quickly on a resale flat with carpentry and tiling, so it pays to have designs, measurements and orders settled before the permit date rather than after. HDB also asks you to inform the HDB Branch managing your flat once the renovation is complete.

Corridors and common property: the Town Council

Your permit covers the inside of your flat. The corridor outside is a different owner's problem. On its page on the function of HDB Branches and Town Councils, HDB explains that Town Councils control, manage and maintain the common property of HDB estates, including corridors, void decks and lifts.

That boundary shows up in the renovation rules in several places:

• Painting the external part of the building, such as common corridor walls and ceilings, and installing awnings or other fixtures outside the flat, are on HDB's list of disallowed works.
• A skip tank in the common area needs the Town Council's approval. One in an HDB car park needs a permit from HDB, and HDB states that repeat offenders without one can be fined up to S$2,000 per offence on conviction.
• Your Town Council may provide debris removal, for a charge, and where it does the debris must go to its designated sites. Debris must never go down the refuse chute or the floor trap.
• Where you rent a common area outside your flat with approval, HDB has a separate set of conditions for gates, grilles, finishes and false ceilings in it.

Penalties for unauthorised works

HDB's position on unauthorised work is set out on both its permit page and its important information page. Work done without a required permit, or not in line with the guidelines, is unauthorised. HDB can require you to discontinue, correct or remove it and reinstate the flat to its original condition. If HDB allows the work to be retained, you pay an administrative fee. HDB can also revoke a permit already granted if its conditions are not followed.

The criminal side sits in the Housing and Development (Renovation Control) Rules 2006. HDB lists three offences that can lead, on conviction, to a fine of up to S$5,000 and other penalties: a flat owner who does not engage a DRC contractor or breaches HDB's renovation rules; a DRC contractor who breaches them; and a contractor not on the DRC who carries out renovations or holds himself out as listed. Under the Composition of Offences Rules HDB may compound an offence instead, and an offender who does not pay the composition sum is prosecuted. Note who is named first: the flat owner. HDB states plainly that you are responsible for the renovation in your flat and for ensuring your contractor follows the guidelines.

How long approval takes

HDB's renovation pages, as we read them on 2 October 2026, do not state a processing time for the permit. Renovation contractors publish their own estimates, but those are their experience rather than HDB's commitment, so we are not going to repeat a number. Two things are worth knowing. HDB may come back asking for a Professional Engineer to supervise demolition, which adds a step. And some works need another agency first: enclosing an interaction balcony needs plans approved by SCDF, and replacing staircase balustrades in an executive maisonette needs a PE's plans approved by BCA, before HDB will issue the renovation permit. Ask your contractor what to expect for your scope.

The floor plan your contractor needs

Every permit that involves walls starts from a drawing of the flat. HDB's permit page says you can use the floor plan given to you in the Sales Brochure during flat selection, and that otherwise you can buy a copy for S$5 through the Purchase of Residential Floor Plan e-Service or at a self-service kiosk at any HDB Branch. The procedure is in how to get your HDB floor plan, and what the plan does and does not show is in HDB floor plan purchase.

Keep the plan's purpose in mind. It is a record of the flat as HDB built it, which is what HDB needs to evaluate your proposal. It is not a record of what previous owners did, and it is not a set of working dimensions. Your interior designer or contractor will need real measurements to design carpentry, order tiles and set out new partitions, and in the normal case they take those measurements themselves on a site visit. For most owners, the HDB plan plus the contractor's own measurements is all that is needed, and nothing further is worth buying.

The exception is a flat that no longer matches its plan: an older flat, or a resale purchase where previous owners moved walls, built in carpentry or merged rooms. Then the marked-up HDB plan and the designer's drawings are describing two different flats, and disputes about what was there before the works began are hard to settle. A measured survey is one option at that point. 3D laser scanning records the flat as it stands, and as-built documentation turns that into a dimensioned plan your designer can work from. The wider problem is covered in what to do when the floor plan is missing or wrong.

To be clear about the boundary: Volumet produces drawings, not permits. We are not on the Directory of Renovation Contractors, we do not submit renovation applications, and a survey from us does not replace HDB's evaluation or a Professional Engineer's supervision. The permit stays with your DRC contractor. If you are unsure whether your flat needs measuring at all, tell us the flat type and what has been altered, and we will tell you honestly if the HDB plan is enough.

Rule of thumb: get the HDB floor plan, choose a DRC contractor, and let them apply. Measurement only becomes worth paying for when the plan and the flat disagree.