HDB Window Replacement Rules in Singapore

Replacing an HDB flat’s windows is one of the most tightly regulated renovation jobs, because a window that fails can fall several storeys onto people below. The core rule is simple: you must engage a BCA-approved window contractor listed with HDB, who applies for an HDB renovation permit before any work starts. It is never a DIY task, and never a job for your general renovation crew. Get it wrong and the penalties are among the heaviest in HDB renovation.

You must use a BCA-approved window contractor

HDB is explicit: “you must engage a Building and Construction Authority (BCA) approved window contractor listed in HDB’s directory for all window installation/replacement work.” An approved window contractor (AWC) is a firm registered with the BCA Contractors Registry under the regulatory workhead RW01; the work can also be done by a licensed builder (workhead GB1 or GB2). Either way, the actual installation must be carried out by a trained window installer — someone BCA has certified by passing its “Safety of Windows” course, for which they need at least 12 months of practical window-installation experience.

You can find an approved contractor on HDB’s online list of BCA-approved window contractors, or by asking at your HDB Branch.

You need an HDB renovation permit

A renovation permit from HDB is required for all window replacement work, and it is the contractor’s responsibility to apply — not yours. The appointed AWC submits the window permit application to HDB before carrying out the works; you can track the status on your MyHDB Page. This sits on top of the general renovation framework: under the Housing & Development (Renovation Control) Rules 2006, you may only engage contractors from HDB’s Directory for renovation in your flat. Window work also carries its own deadline — window-only works must be completed within two weeks of the permit date (versus one month for an existing block or three months for a newly completed block for general renovation). For how permits work across other jobs, see the HDB renovation permit guide.

What the rules require of the new windows

HDB sets out minimum specifications for each window type, which your contractor must meet. These are safety requirements, not style preferences.

Key HDB specification for each HDB window type on replacement. Source: HDB, Renovation Guidelines for Window Works, 2026.

Source: HDB, Renovation Guidelines for Window Works, 2026.

There is also a matching rule that trips up owners who want a different look. For flats handed over from 1 July 2007, any window you install or replace “must be of a similar colour scheme, proportion and type (i.e. sliding to sliding, casement to casement) as that of the original windows provided by HDB.” In other words you generally cannot convert a casement window to a sliding one, and the colour must match. (A service-yard window only needs to match the colour scheme.)

What you cannot do

A few window changes are simply not allowed, or need no permit at all — it helps to know which is which.

Retrofitting: the rivet rule for older casement windows

Separate from replacement, owners of older flats have a retrofitting duty. Aluminium casement windows fixed with aluminium rivets are a known falling hazard, so BCA requires that all aluminium rivets at the variable-geometry friction stays be replaced with type 304 stainless-steel rivets (to BS EN 10088 or equivalent). Contractors who find casement windows still on aluminium rivets must report them to BCA.

The hardware counts are specific. An existing casement window should have at least 3 rivets or screws on each side of the friction stay; a retrofitted or newly replaced casement window must have at least 4 on each side. This is routine work for an approved contractor, and it is the single most common window rectification in older HDB blocks.

Replacing a window with an integrated safety barrier

Some ¾-height and full-height windows double as a safety barrier — a barrier preventing a fall where there is a vertical drop of 1,000mm or more. Replacing or reinstating these is a bigger deal. Normally a Professional Engineer must design the works and submit structural plans to BCA. To save time and cost, owners may instead adopt one of BCA’s standardised designs (14 of them, introduced in March 2023); using these makes the job “insignificant building works,” so no Professional Engineer, plan approval or Commissioner of Building Control permit is needed. Either way the work must still be done by an approved window contractor or builder with a trained window installer who has completed BCA’s “Replacement and reinstatement of safety barriers integrated with windows” module.

The process, step by step

Pulling it together, a compliant window replacement runs in a set order.

1. Appoint a BCA-approved window contractor listed with HDB (RW01), or a qualifying builder, with a trained window installer.
2. The contractor applies for the HDB renovation permit before any work begins; check the status on MyHDB Page.
3. Works are carried out to HDB’s specifications for your window type, matching the original type/proportion/colour where the post-July-2007 rule applies.
4. The contractor submits the window report to BCA within 14 days of completion and gives you a copy at no extra charge — keep it for your records.
5. Check the installation. If parts are loose or missing, contact the contractor to rectify; if they refuse, inform BCA.

Why it matters: you are responsible, and the penalties are steep

As the flat owner you are responsible for the upkeep of your windows, and HDB recommends checking them once every six months. The penalties make the point:

Penalties and the ground-floor exemption for HDB window rules. Source: HDB, 2026.

• A window that falls due to lack of maintenance: a fine not exceeding S$20,000 and/or imprisonment for up to 12 months.
• Failing to retrofit casement windows with stainless-steel rivets: a fine not exceeding S$5,000 or imprisonment up to 6 months, or both.

There is one exemption: windows in flats on the lowest level are outside BCA’s Building Control Regulations, because nothing can fall from height. Every floor above must comply. Windows are regulated separately from, but alongside, other renovation jobs such as electrical works — and if you are budgeting a whole flat, factor them into the 5-room renovation cost or your own flat type’s guide.

Frequently asked questions

Can I replace my HDB windows myself? No. All window installation and replacement must be done by a BCA-approved window contractor listed with HDB, using a trained window installer. DIY and general handymen are not permitted.

Do I need a permit to replace HDB windows? Yes. An HDB renovation permit is required for all window replacement, and your approved window contractor applies for it before starting.

Can I change from casement to sliding windows? Generally no for flats handed over from 1 July 2007, where replacements must match the original window’s type, proportion and colour. Older flats have more latitude but must still meet the safety specifications.

Can I replace a full-height window? Generally no — HDB states the replacement of full-height windows (including ¾-height and bay windows) is strictly not allowed, with an exception where a damaged frame genuinely requires complete replacement. A full-height window that also forms a safety barrier has its own PE or standardised-design route for the barrier portion.

What happens if my window falls? If it falls through lack of maintenance, you can face a fine of up to S$20,000 and/or up to 12 months’ imprisonment, so six-monthly checks and prompt repair by an approved contractor matter.

Related

• Electrical works: rules and costs
• HDB renovation permit guide
• HDB hacking and wall rules
• How to choose a renovation firm
• 5-Room HDB renovation cost

General information only, not legal advice. Rules, fees and penalties are from official HDB and BCA pages (approximate, November 2026) and change over time — confirm current requirements with HDB, BCA and a BCA-approved window contractor before you start.