HDB Window Replacement: Rules, Permits and Safety Checks Before You Renovate

Windows are easy to forget when you plan a renovation, until a casement stay feels loose or a sliding panel sticks. In an HDB flat, window work has its own rules: only certain contractors can do it, most replacements need a permit, and new windows usually have to match the originals.

This guide sums up what HDB and the Building and Construction Authority (BCA) say about replacing, repairing and maintaining windows in HDB flats. It is general information, so check the latest rules for your own flat with HDB before you start.

Who can replace windows in an HDB flat

According to HDB's renovation guidelines for window works, all window installation and replacement work must be done by a BCA approved window contractor listed in HDB's directory. BCA explains that an approved window contractor is a firm registered with the BCA Contractors Registry under the regulatory workhead RW01, and the actual installation is done by a trained window installer.

HDB also notes that engaging a window contractor is a private arrangement between you and the contractor. Before any work, HDB suggests asking about the type and extent of work needed and all chargeable costs, comparing quotes from more than one contractor, and reading the terms of engagement.

When you need a permit

HDB states that a renovation permit is required for all window replacement work, and that the approved window contractor applies for it before starting. HDB's home care guide adds that you can log in to MyHDB Page to check the status of the application.

Some smaller window-related items do not need a permit, according to HDB's guidelines:

• Window film: placing film on existing windows or balcony doors, as long as it is non-reflective or does not exceed 20% reflectance

• Blinds and curtain rails: bamboo chicks, venetian blinds or curtain rails installed internally

• Internal grilles in older flats: for flats handed over before 1 July 2007, metal grilles of any design fixed internally, as long as they do not protrude from the building facade

For other building works, our HDB renovation permit guide explains what needs approval and what does not.

What your new windows must match

For flats handed over from 1 July 2007 onwards, HDB requires replacement windows to be of a similar colour scheme, proportion and type as the original HDB windows, so sliding stays sliding and casement stays casement. Service yard windows only need to match the original colour scheme. Grilles at the service yard or balcony parapet of these flats must follow HDB's approved designs, which you can find on your renovation factsheet or by logging in to MyHDB Page.

HDB also sets panel widths for windows installed on a parapet: 500mm to 700mm for casement windows and 500mm to 1200mm for sliding windows.

Full-height, 3/4-height and bay windows

HDB says replacing full-height windows, including 3/4-height and bay windows, is strictly not allowed. Permission may be granted where a damaged frame needs a complete replacement.

Where a window is integrated with a safety barrier, BCA introduced standardised designs in March 2023 that flat owners may adopt, with seven designs each for 3/4-height and full-height windows. These works must be carried out by a licensed builder or an approved window contractor with trained installers who have done BCA's module on safety barriers integrated with windows. If a standardised design cannot be used, HDB says the flat owner must engage a Professional Engineer (Civil) to design the works and submit plans to BCA. Either way, the new window must match HDB's original in type, dimension and colour scheme.

If you have an older resale flat with bay windows, our 5-room and executive resale guide covers other checks to make before you plan carpentry around them.

Casement windows and stainless steel rivets

HDB's home care guide on windows says you need to retrofit your casement windows if they do not meet the retrofitting requirements. BCA's windows safety page explains that retrofitting means replacing all aluminium rivets at the window stays with type 304 stainless steel rivets, done by an approved window contractor and trained window installer.

HDB states that failing to retrofit your windows with stainless steel rivets may lead to a fine not exceeding S$5,000, imprisonment for up to 6 months, or both. Windows in flats on the lowest level are exempted, as there is no danger of falling from height.

Upkeep is the owner's job

HDB reminds owners and occupants that they are responsible for the upkeep of the windows in their flat, because a falling window could cause serious injury to people below. BCA's simple routine is check, clean, change: check that your windows work smoothly, keep them clean, and change worn parts when needed. If you are not confident checking your own windows, BCA suggests engaging an approved window contractor to inspect them.

If your block is due for the Home Improvement Programme, our HDB HIP timing guide explains how HIP affects the laundry window and other works you may be planning.

A simple window checklist for your renovation

• List your windows: note which are casement, sliding or louvred, and which are full-height, 3/4-height or bay windows

• Check the contractor: confirm the window contractor is on HDB's list of BCA approved window contractors before you sign

• Confirm the permit: ask the contractor to apply for HDB's window permit and track it on MyHDB Page

• Match the original: for flats from 1 July 2007, keep the same type and similar colour scheme and proportion

• Plan carpentry around windows: keep window seats, wardrobes and curtain pelmets clear of stays, handles and sliding tracks

• Ask for the report: HDB says the contractor must submit the window report to BCA within 14 days of completion, should give it to you at no extra charge, and you should keep a copy

• Inspect at the end: check for loose or missing parts and use our renovation handover checklist before your final payment

Where Blackwoods Interior stands

• Blackwoods Interior Pte. Ltd. (trading as Blackwoods Interior), UEN 201909521M

• CaseTrust accredited for Renovation Businesses (the standard tier, not Gold), valid through 28 April 2028

• Listed on HDB's Directory of Renovation Contractors (DRC)

Talk to Blackwoods Interior

Planning a renovation that touches your windows? Book a free 30-minute consultation: WhatsApp us at 8754 3212 (Mon-Sat, about 10:00-19:00 SGT) or email Hello@bwi.sg. Visit www.bwi.sg to see more.

Cover image: illustrative concept, not a completed Blackwoods project. This guide is general information based on HDB's window works guidelines, HDB's home care guide on windows and BCA's windows safety page, checked on 25 October 2026. Rules can change, so check the latest requirements for your flat with HDB before you start any window works.