As part of HDB’s efforts to enhance the safety of windows installed in HDB flats, HDB has introduced the minimum safety requirements for window installation/replacement of new aluminium windows since 22 August 2003.

From 1 Oct 2004, flat owners must engage only BCA approved window contractors listed with HDB to carry out installation/replacement of new aluminium windows in HDB flats. Flat owners need to reflect the BCA approved window contractors and the name of their trained installer in the application for window permit when they submit the application electronically to HDB.

For repair of existing aluminium windows, please refer to the safety requirements.

(Drawing on Aluminum Casement Windows)

Parts	Requirements
Friction stay	Stainless steel grade 304 or equivalent Minimum thickness not less than 2.5 mm Length not less than 1/2 width of window leaf
Window leaf	Maximum width not exceeding 700 mm
Aluminium section for screw connection	Minimum thickness 2.75 mm
Connection of friction stay to window frame	Stainless steel grade 304 self-tapping screw of minimum size no. 8 (4 mm) If aluminium section is not less than 3mm thick, epoxy coated screws can be used Minimum 4 screws on each side of friction stay
Corner brackets (if used) for corners of window leaf	Zinc casting corner brackets

(Drawing on Aluminium Sliding Windows)

Parts	Requirements
Safety devices	To install the following: a. Polyethylene sliding window self-locking safety device (2 nos. per panel) b. Synthetic resin stoppers at top of window outer frame [minimum 2 nos. per panel width and repeat the same along the track The stopper shall be fastened with stainless steel grade 304 or equivalent rivet/screw of minimum 4 mm diameter Refer to drawing for spacing of stoppers] c. Aluminium bottom outer frame with fixed angle facing outside Dimension "b" shall be minimum 1.5 times dimension "a" [refer to drawing]
Sliding panel	Maximum width not exceeding 1.2 m

(Drawing on Adjustable/Fixed Louvre Vent)

Parts	Requirements
Glass louvres	Minimum glass thickness not less than 6 mm Wire-glass type
Glass louvres safety device	Aluminium U-channel cleat at every glass louvre

Types of Building Work	Need Permit?	Subject to the following Guidelines / Conditions
Replacement of existing window's clear sheet glass with tinted/obscured glass	No	Not applicable.
Placement of Sun'X' non-reflective film over the clear sheet glass of existing windows/balcony doors	No
Installation of bamboo chicks/venetian binds/curtain rail internally	No
Replacement/installation of window on parapet at window opening	Yes	Width of window panel: Casement window: 500mm to 700mm Sliding window: 500mm to 1200mm Safety stoppers must be installed for sliding windows All screws used must be of stainless steel type. View the Window Safety for more information For flats handed over from 1 Jul 2007 onwards Windows installed/replaced must be of similar colour scheme, proportion and type (i.e. sliding to sliding, casement to casement) with that of the original windows provided by HDB.
Installation of windows# on parapet at open balcony building facade # For some precincts where the design of the balcony space adopted the URA's balcony Gross Floor Area (GFA) incentive scheme in the residential development, windows are not allowed to be installed at the balcony. Examples of such precincts include the Design, Build and Sell Scheme (DBSS) flats and The Pinnacle@Duxton. [You can view the GFA incentive scheme at URA's website]	Yes
Installation of grilles at service yard / private balcony (if any)	Yes	For flats handed over from 1 Jul 2007 onwards Window grilles installed must be of HDB approved designs. Flat owners can view the specific renovation guidelines including approved grille's design via "My HDBPage"
Installation/replacement of internal metal grilles of any design at window and balcony openings	No	For flats handed over before 01 July 07 Metal grilles must be fixed internally and cannot protrude from the building façade
Installation of internal metal grilles of any design at double-storey private balcony of maisonette	No
Installation of metal grilles at double storey corridor end balcony of maisonette	No
Installation of metal grilles of any design at interaction balcony	No	Height of metal grilles must not exceed height of unit Shall not store any combustible material at the balcony area
Replacement/removal of mild steel/stainless steel railing on top of balcony parapet	No	This is applicable only to mild steel railing on top of reinforced concrete parapet The height of the balcony parapet from finished floor level must be at least 1000 mm To apply two coats of the rust inhibitor to the surface of exposed steel bars (where the steel bars were anchored into) before any finishing work is done to prevent rusting

From time to time, HDB has been introducing new and distinctive features in HDB flats to enhance the aesthetic appearance of the block and the overall town. Some of the common distinctive features introduced are full height windows (3/4 height windows), windows with coloured frame/glass panel and windows with different proportions.

In July 07, HDB has introduced some control measures to ensure that the aesthetic appearance of the block/precinct will not be marred.

The following enhanced window guidelines have been implemented:


Replacement of full height windows is strictly not allowed, unless with valid reasons, such as badly damaged frame which require a total change of windows.

Examples of full height windows.

If replacement is necessary, flat owners need to engage a BCA-approved window contractor to submit an application for renovation permit to HDB electronically. The replacement must comply with the colour scheme, proportion and type [ie casement to casement, sliding to sliding] with that of the original windows provided by HDB, in addition to existing requirement to engage a Qualified Person (QP) to certify the lateral loading.

The QP is required to submit structural calculations and drawings to Building and Construction Authority (BCA) for regulatory approval via CORENET (COnstruction and Real Estate NETwork). Once the approval is given by BCA, the BCA-approved window contractor is to submit the BCA's "Permit to Commence Structural Work" and approved drawings to HDB for the issuance of the renovation permit.


(i) Flats handed over from 1 Jul 07 onwards

For installation/replacement of windows at balcony/parapet, flat owners need to comply with the colour scheme, proportion and type [ie casement to casement, sliding to sliding] with that of the original windows provided by HDB, in addition to existing requirements.

(ii) Flats handed over before 1 Jul 07

For installation/replacement of windows at balcony/parapet, an advisory note will be incorporated into the renovation permit to inform flat owners to comply with colour scheme and proportion with that of the original windows provided by HDB.


Flat owners will need to install using HDB approved grilles design, which are given during the booking of flat/collection of keys via a renovation fact sheet for flats handed over from 1 Jul 07 onwards [see sample renovation fact sheet].

Last Updated on 30 Jul 2010