HDB Window Grilles and Safety Grilles: Rules in Singapore

Window grilles are one of the first safety items many HDB households add. Whether you need a permit depends on where the grille goes, when your flat was handed over, and whether you are touching a safety barrier that came with the windows.

This guide covers grilles, internal blinds and films, parapet railings and integrated safety barriers. It is not about replacing the window panels themselves — use our HDB window replacement rules for that, including who may install aluminium windows. For enclosing a balcony with blinds, see our balcony enclosure and blinds guide. Always check HDB's current renovation guidelines for window works and your own flat's renovation factsheet or MyHDB Page before you start.

What you can usually install without a permit

HDB's window-works table lists these as not needing a permit, subject to the conditions on the same page:

• Film on existing window or balcony-door glass: no permit, provided the film is non-reflective or does not exceed 20% reflectance

• Internal bamboo chicks, venetian blinds or a curtain rail: no permit

• Internal metal grilles of any design at a window and balcony parapet: no permit, but HDB states this as applicable to developments handed over before 1 July 2007. The metal grilles must be fixed internally and cannot protrude from the building facade

HDB also lists no-permit grille works at some maisonette positions and at an interaction balcony. At an interaction balcony, the grille height must not exceed the height of the unit, and you must not store combustible material there.

When a permit is needed — and the 1 July 2007 split

Installation or replacement of grilles at a service yard or balcony parapet does need a permit.

For flats handed over from 1 July 2007 onwards, those service-yard or balcony-parapet grilles must be of HDB-approved designs. HDB tells owners to refer to the renovation factsheet given during booking or key collection, and to view the approved designs for the service yard or open balcony by logging in to MyHDB Page.

Do not assume every internal grille is automatically exempt. The "any design, no permit" wording is tied to developments handed over before 1 July 2007. If your keys came later, check the approved designs for your block before anyone fabricates. Your own factsheet and MyHDB Page are the source of truth — not a neighbour's grille two blocks away.

Installing a window on a parapet is a separate yes-permit item on the same HDB table, with its own size and matching rules. Treat that as window work and follow the window replacement guide. Our HDB renovation permit guide explains how permit items are submitted more generally, and grille installation still has to respect HDB renovation hours.

Railings on top of a balcony parapet

HDB lists replacement or removal of a mild steel or stainless steel railing on top of a balcony parapet wall as not needing a permit, but only with these conditions:

• It applies only to a mild steel or stainless steel railing on top of a reinforced concrete parapet

• The height of the balcony parapet wall from finished floor level must be at least 1000mm

• Apply 2 coats of rust inhibitor to the surface of exposed steel bars (where the steel bars are anchored into) before any finishing work is done, to prevent rusting

This is a narrow exemption for a railing sitting on top of an RC parapet that already meets that height. It is not a free hand to remove every barrier you can see.

Safety barriers integrated with 3/4 and full-height windows

Some HDB flats have safety railings or a safety barrier integrated with 3/4-height and full-height windows. On HDB's application for a renovation permit page, these are described as installed for the safety of residents, and designed to withstand horizontal loading as prescribed in British Standard (BS) 6399: Part 1 — Loading for buildings.

HDB says flat owners are strictly not allowed to remove these barriers unless they are damaged.

If a damaged safety barrier integrated with those windows needs replacement, HDB says owners may adopt BCA's approved standardised window designs from BCA's website, subject to these conditions:

• The works must be carried out by Licensed Builders (LB) or Approved Window Contractors (AWCs) with trained window installers (TWIs) who have completed BCA's course "Module on replacement and reinstatement of safety barriers integrated with windows"

• The works must satisfy the objective and performance requirements set out in the Fifth Schedule relating to the safety of windows, safety from falling, use of glass at height, and any other requirement in these Regulations

• The LB or TWI must submit a certification of completion declaring that the works were carried out in accordance with the standardised designs, to BCA's Commissioner of Building Control, within 14 days of work completion

HDB adds that the LB or AWC will assess the existing window before advising whether those standardised designs can be used. If they cannot, or if a damaged safety railing needs replacement, you will need to engage a Professional Engineer (PE) in civil engineering. A Qualified Person who is a PE in civil or structural engineering must design and/or certify the lateral loading and submit structural calculations and drawings to BCA through CORENET. After the plans are approved, the flat owner, the QP supervising the works and the Licensed Builder carrying out the replacement must jointly apply to BCA for a permit to commence structural works. Your appointed approved window contractor then submits that BCA permit, with the approved drawings, to HDB to obtain a renovation permit before work starts.

If you are replacing the window itself rather than only dealing with a damaged barrier, read the window replacement guide for HDB's separate rules on full-height, 3/4-height and bay windows.

A simple grille and barrier checklist

• Check your handover date against 1 July 2007 before anyone quotes an "any design, no permit" internal grille

• Look up approved designs on your renovation factsheet or MyHDB Page if the grille is going on a service yard or balcony parapet

• Do not remove an integrated safety barrier unless it is damaged, and use the BCA standardised-design or PE (Civil) path HDB describes for a damaged replacement

• Plan the opening as carefully as a main door and gate: unauthorised changes can be treated as unauthorised work

HDB's guidelines can change, and your block may have extra notes in its own factsheet. Confirm the current rules with HDB before fabrication or installation begins.

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 window grilles or a renovation that touches your windows, service yard or balcony parapet? 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 renovation guidelines for window works and HDB's application-for-a-renovation-permit page (safety barrier section), checked on 8 November 2026. Rules can change, so check the latest requirements for your flat with HDB, your renovation factsheet and MyHDB Page before you start.