Windows Are One of the Most Regulated Parts of an HDB Renovation
Most Singapore homeowners assume window replacement is straightforward. Pick a style, call a contractor, done. In practice, HDB window replacement sits within a set of regulations that governs not just the type of window you can install but the contractor you must use, the permit requirements and even the specific safety fittings that must be included. Getting this wrong can result in an order to remove and replace the windows at your cost.
Here is what you actually need to know.
HDB’s Rules on Window Replacement
HDB requires that all window replacements in HDB flats be carried out by an HDB-approved window contractor. The window must be installed with window grilles or child safety devices if there are children below 12 years old in the household. All windows above the first floor must have window grilles or safety stoppers that prevent the window from opening more than 100mm without a deliberate override.
Window replacement also requires an HDB renovation permit. This is not a formality. HDB takes window safety seriously following incidents over the years and compliance checks do happen. Working with an approved contractor and getting the permit in order before works begin is not optional.
Casement vs Sliding: The Practical Difference
The two most common window types in HDB flats are casement windows and sliding windows. Each has genuine advantages and the right choice depends on your specific situation.
Casement windows hinge at the side and open outward. They provide a full opening, which means excellent ventilation when open. They seal more tightly when closed, which is better for noise insulation and keeping rain out during Singapore’s downpours. The maintenance requirement is slightly higher as the hinges and locking mechanism need periodic attention.
Sliding windows move horizontally along a track. They require less maintenance, are simpler in mechanism and are generally the lower-cost option. The trade-off is that a sliding window can only open to 50 percent of its total width at maximum, which limits ventilation compared to a fully opening casement. They are also less effective at keeping out driving rain.
Sliding casement windows combine elements of both: a sliding sash that can also tilt or pivot. These are a relatively newer option in Singapore HDB replacements and provide more flexibility than either a pure casement or a pure sliding window in certain configurations.
The Safety Requirement That Often Gets Overlooked
Under HDB regulations, all windows in residential flats must be fitted with safety devices that prevent them from opening more than 100mm if there are children under 12 in the household. In practice, most reputable window contractors include window safety stoppers as standard regardless of household composition, because HDB inspectors will check.
For higher floors, the requirement is more stringent and the grille design must meet HDB’s specifications on bar spacing and structural rating. Discuss this explicitly with your window contractor before fabrication begins.
What Does Window Replacement Cost?
Pricing varies significantly by window size, type, material and floor level. As a general guide for aluminium frame windows, which are the standard in HDB replacements:
- Standard sliding window (900mm x 1200mm approximately): $300 to $600 per window
- Standard casement window: $400 to $800 per window
- Larger windows or those requiring scaffolding access at high floors: add $200 to $600 per window for access costs
These figures include installation but not grilles, which are typically quoted separately at $80 to $200 per window depending on design.
When to Replace vs Repair
If your existing windows have damaged or corroded frames, broken locking mechanisms, failed weather seals or visible gaps that let in water during rain, replacement is the correct answer. If the frame is structurally sound and the issue is limited to a worn seal or a stiff latch, repair is often sufficient and significantly cheaper.
Have a contractor assess the windows before committing to full replacement. A good contractor will tell you honestly if repair is viable. Empire Works handles window replacement as part of broader renovation projects. Contact us to discuss your windows as part of your overall renovation scope, or to find out whether repair or replacement makes more sense for your specific situation.
