Casement Windows in Singapore — A Guide for HDB Homeowners in 2026
At a Glance
- What is a casement window? A window with a sash that opens by swinging away from the frame on hinges or friction stays.
- Are casement windows common in HDB flats? Yes. They are one of the common opening types found in HDB homes.
- What needs maintenance? The friction stay, rivets or screws, hinges, gasket, and locking mechanism should be kept in good condition.
- Can an HDB casement window be replaced? Yes, but only a BCA-approved window contractor can carry out the replacement, and the applicable approval requirements must be followed.
- How much does replacement cost? 9 Power’s indicative price is around S$300–S$600 per panel, before additional features and depending on the specification.
Introduction
Look at almost any HDB block in Singapore, and you’ll spot them: glass panels that swing outward from the façade, held open by slim metal arms.
That’s a casement window.
Unlike a sliding window, which moves along a horizontal track, a casement window has hinges at one side and opens outward. They’re common in HDB flats, but they also come with a maintenance issue homeowners shouldn’t ignore: the hardware that holds the sash in place can deteriorate over time.
This guide explains what a casement window is, how the opening mechanism works, why fallen casement windows remain a safety concern in Singapore, and when repairing an old window makes more sense than replacing it.
What Is A Casement Window?
A casement window is a type of window that has a frame along which a glazed panel, called the sash, attaches and opens in a swinging operation instead of sliding along a track.
Since the frame has hinges on one of the sides, the window opens towards the exterior or interior. Singaporeans also call it a swing or hinged window for that reason.
Casement windows are common in bedrooms, kitchens, and living rooms in HDB homes in Singapore because they provide excellent ventilation and unobstructed views.
How Do Casement Windows Work in HDB Flats?
Casement windows open by swinging on friction stays across the hinges. They provide strong wind resistance, controlled opening, and quiet operation. A handle locks everything shut against a rubber gasket that keeps the rain out.
A side-hung casement pivots on a vertical edge and opens like a door, giving you full airflow and access to the outside of the glass for cleaning. A top-hung casement tilts out from its top edge, so it can stay open during a light shower. HDB’s maintenance guidance treats both the same way, and our top casement windows work on the same principle.
Why Are Casement Windows Common in Singapore HDB Flats?
One reason casement windows work so well in Singapore is that they fit Singapore home requirements perfectly. Let me explain how:
- Excellent Ventilation: Singapore has high humidity year-round, with average relative humidity hovering between 70% and 90% daily, so closed windows aren’t a smart choice. Casement windows work well here; their wide openings let fresh air in, which is essential in Singapore’s humid climate.
- Space-Saving: The average floor area for non-landed private residential homes in Singapore is about 83 square meters; since casement windows open outward, they take up less space and are a good option for HDB flats.
- Good Sealing: Casement windows offer good sound and weather insulation.
- Customisable Design: At 9 Power Aluminium & Glass, we provide custom-made windows in Singapore.
Casement Vs Sliding Windows: Which Suits Which Room?
| Casement window | Sliding window | |
| How it opens | Sash swings outward on a friction stay or hinge | Panels slide sideways along a track |
| Opening for airflow | A side-hung sash opens the whole panel | About half the opening on a two-panel window |
| Space needed | Clearance outside for the sash to swing | None beyond the frame |
| Main part to check | Friction stay rivets | Stoppers and strips |
| Fallen cases, Jan to Nov 2023 | 19 | 15 |
To decide better, map the opening area and daily use, then compare clear ventilation, reach, operating force, restrictors, locks, cleaning access, drainage, and replacement parts.
You’ll sometimes hear that the safe move is to swap every casement for a sliding window and be done with rivets for good. We don’t agree. BCA’s 2023 figures put sliding windows just four cases behind casement, and they fail for an equally preventable reason: worn or missing stoppers and strips meant to keep the panel in its track. Changing the opening type swaps one maintenance check for another.
Repairing or Replacing an HDB Casement Window
Not every casement window problem requires a full replacement. If the aluminium frame is still in good condition, you may be able to repair issues such as a loose gasket, stiff hinge, or worn hardware. A qualified window contractor should inspect a cracked glass panel, damaged friction stay, or corroded fixing before you decide what to do.
Replacement is usually worth considering when the frame is damaged, corrosion is extensive, the window no longer closes properly, or several components need to be replaced at once. If the existing frame is sound, replacing individual parts can be a more practical option than installing a completely new window.
For HDB flats, only a BCA-approved window contractor listed with the Housing and Development Board can replace windows, and you must obtain the required renovation approval before work begins.
If you are unsure whether your existing casement window can be repaired, a site inspection can help determine whether the frame, hardware, and fixings are still suitable for continued use.
For budgeting, 9 Power’s aluminium casement windows generally cost around S$300–S$600 per panel, depending on the configuration and materials selected. A six-panel replacement would therefore be roughly S$1,800- S$3,600 before extras such as grilles, insect screens, upgraded glass, or special finishes. The actual quotation will depend on the window measurements and specification.
A site measurement is the simplest way to determine whether you need a repair or replacement and what the work will likely cost.
Are Casement Windows a Safety Hazard?
Casement windows are not inherently unsafe, but they have a well-documented vulnerability in Singapore’s climate. BCA publishes a fallen-window count every year, and casement windows have made up at least half of it every year since 2019.
| Year | Fallen windows recorded | Casement windows | Share |
| 2019 | 48 | 24 | 50% |
| 2020 | 49 | 32 | 65% |
| 2021 | 43 | 22 | 51% |
| 2022 | 33 | 17 | 52% |
| 2023 | 35 | 19 | 54% |
In its 2023 update, BCA traced fallen casement windows to corroded, weakened aluminium rivets that could not keep the sash in its place. In Singapore’s high humidity, aluminium rivets corrode and become weak over time, causing the sash to detach and fall, sometimes without warning.
BCA’s Rivet Rule
According to BCA’s guideline after 2004, homeowners must replace rivets on casement windows with the ones made of stainless steel. The rivets should be Grade 304 stainless steel that complies with the relevant standards. Stainless steel resists corrosion far better in Singapore’s environment and holds the friction stay securely for much longer.
Homeowners who don’t retrofit aluminium rivets can face fines, jail time, or both. Moreover, lack of maintenance is the reason for a window falling; the penalties can be higher.
HDB also sets hardware standards for casement windows. Proper installation by a BCA-approved contractor is required for any replacement or retrofitting work.
How Casement Windows Can Become Less of a Hazard
You can prevent the risk with two practical steps:
Opt for stainless steel rivets
If your windows have aluminium rivets (common in older HDB flats or earlier renovations), you should take the services of a BCA-approved window contractor to retrofit them. This is a targeted repair rather than a full window replacement in many cases.
Inspect and maintain twice a year
According to the Housing and Development Board and Building and Construction Authority, homeowners should check all windows at least twice a year. In case of casement windows, look for:
- Rusty, loose, or broken rivets or screws on the friction stay
- Bent, loose, or stuck friction stays
- A sash that does not close flush against the frame
- A gasket that has worked loose
Clean and lightly lubricate moving parts, and tighten any loose screws you can safely reach. Have an approved contractor handle anything involving rivets, friction stays, or glass.
When you follow these steps, a casement window is no more hazardous than a sliding window. The hardware simply needs to be the right material and kept in good condition.
If your windows feel stiff, rattle, show signs of corrosion, or no longer stay open reliably, a professional inspection is the safest next step. A BCA-approved contractor can check the rivets, friction stays, and frame condition, then recommend whether you need a rivet retrofit, hardware repair, or full replacement.
Not Sure If Your Casement Windows Need Repair or Replacement?
If your HDB casement windows are stiff, damaged, corroded or no longer closing properly, 9 Power can inspect them and recommend whether repair or replacement makes more sense.
Book a free site measurement with 9 Power to have your existing windows assessed and get a quotation based on your actual window condition and requirements.
FAQs
Is a top-hung window a casement window?
Yes. Singapore’s legal definition includes windows that open on hinges, so top-hung and side-hung windows both count. They’re subject to the same rivet rules and the same six-monthly checks.
Can I replace my HDB casement window myself?
No. HDB requires a BCA-approved window contractor listed in its directory to carry out all window installation and replacements in a flat. You can clean, lubricate, and tighten loose screws yourself. Anything involving rivets, friction stays, corner brackets or glass needs an approved contractor.
How often should I check my casement windows?
It is recommended to check your windows twice a year, which is BCA’s advice for every window type. That includes windows already fitted with rivets made of stainless steel. Check the rivets on the friction stay, make sure the sash closes flush, and push the gasket back into its groove if it’s working loose.
How much does a casement window cost in Singapore?
As a general guide, an aluminium casement window from 9 Power costs S$300 to S$600 per panel. Size, the number of panels, glass type, frame finish, and extras like screens all affect the price, so rely on a measured quotation.