Most BTO owners we measure for don’t realise their bedroom faces directly into the morning sun until they wake up at 6:45am on day three. By the time we get the call, they’ve spent two weeks sleep-deprived and a fortnight Googling “blackout curtain Singapore.” It’s a fixable problem, but the spec matters. A curtain made of blackout fabric isn’t the same thing as a blackout curtain. Here’s the difference.
What “Blackout” Actually Means
“Blackout” is a fabric specification. The dense weave (often a triple-pass weave with a foam or thermal layer) blocks roughly 99% of light from passing through the cloth itself. That last 1% (the part that wakes you up) comes from gaps. Specifically:
- The gap between the top of the curtain and the ceiling.
- The vertical gap on each side, where the fabric meets the wall.
- Any seam where two pieces of fabric were joined.
- Pinholes in the weave where stitching has compromised the backing.
A blackout curtain that ignores those four points isn’t blackout. It’s dim. There’s a real difference between dim and dark: about three hours of extra sleep on a sunny morning.
The fabric is the easy part. The rest is what makes it work.
The Four Spec Decisions
1. Fabric Weight
Standard blackout fabrics weigh around 280 to 340 g/m². Premium triple-weave with thermal backing runs 380 to 420 g/m². For a typical HDB master bedroom, standard is fine; for a west-facing window with afternoon sun, the premium fabric reduces heat enough to feel it on your skin when you stand near the window.
Don’t over-spec for performance you don’t need. We’ve turned customers off premium fabric because their north-facing bedroom genuinely doesn’t need it, and the price difference is around 30%.
2. Track Style
HDB ceilings have a 2 cm depth limit on track recesses. That constrains options. The two we use most:
- Wave (S-fold): A continuous soft S-curve. Modern, minimalist, works with most fabrics. Best with motorised systems.
- Pinch-pleat: Sharper folds, more traditional. Sits better against shorter HDB drops than wave does.
Ripple-fold looks good in a 3m drop but tight to a 1.8m HDB bedroom window. It can look apologetic. We’ll say so during the measurement.
3. Side Returns
This is where most generic curtain installs fall apart. A “return” is the curtain wrapping back toward the wall on each side, sealing the vertical gap. We extend the track 15 to 20 cm past the window frame on each side, so the closed curtain has a horizontal overlap that blocks light coming in at an angle.
Without returns, light leaks in vertical strips, particularly noticeable when a streetlight is at an angle to the window, or when a neighbouring HDB block has facade lighting.
4. Lining and Backing
Most blackout fabrics have integrated backing. For decorative fabrics where you want a particular face colour but blackout performance behind it, we add a separate liner. The liner adds 20 to 30% to the cost but means you don’t have to choose between aesthetics and performance.
The Questions to Ask Before You Sign
When you’re getting quotes (from us or anyone), here’s what to ask:
- Is the install quoted for ceiling-mount or wall-mount? Ceiling-mount almost always seals better, but isn’t possible in every HDB.
- How far does the track extend beyond the window frame? Less than 10 cm of return on each side and you’ll see light strips at the edges.
- Is the fabric standard blackout or premium? Standard is usually right for most rooms, but you should be told which one you’re getting.
- Is installation included in the quote? Some vendors price the curtain separately from the fitting fee. Ours always includes both.
- What’s the warranty? We offer 2 years on standard blackout, 3 years on premium, and 5 years on tracks and hardware.
Common Mistakes
Three patterns we see often:
Buying off-the-shelf “blackout” curtains from generic retailers. The fabric might be blackout-rated, but the curtain is sized for a generic window, not yours. The gap on each side defeats the fabric’s purpose. If you’re going to invest in blackout, custom-measure is non-negotiable.
Choosing a darker face fabric to “make sure it blocks light.” The face colour doesn’t determine blackout performance: the backing does. You can have an off-white or beige blackout that performs identically to a navy one.
Trying to retrofit blackout to an existing curtain track. Sometimes possible, but the track usually wasn’t sized for the heavier fabric weight, and the existing brackets won’t have the load-bearing rating. We’ve replaced more “retrofit blackout” jobs than we’ve successfully installed onto existing tracks.
How Long It Takes
From the free in-home measurement to install:
- Standard blackout: 2 weeks.
- Premium blackout: 3 to 4 weeks.
- Motorised blackout: add 1 to 2 weeks for the controller and Somfy parts.
Install itself is a 2 to 4 hour job per room with two installers. We protect floors, hang and align, run a light-leak test (turn off the lights, look for strips), and clean up. You’ll have working curtains the same day we arrive.
If You Are Moving In Soon
BTO handover and curtain install can be tight if you’re aiming for ready-to-move-in. We’ve done same-week installs the day after key collection, but it requires booking the measurement at least 3 weeks before handover. Earlier is better.
If you’ve just got your keys and you’re looking at a sun-trap bedroom right now, book a measurement and we’ll come out within the week. We’ve been doing this since 2007, and the BTO bedroom is genuinely the most common job we measure for.