Choosing the right glass for an Indian home
Heat, glare, noise and safety pull in different directions, and no single glass wins on all four. Here is how the six common types actually compare.
Most window conversations in India start with the frame and end with the price. The glass gets picked last, usually by whoever is installing it. That is the wrong order: the frame decides how long the window lasts, but the glass decides how the room feels.
There are six types in common use. None of them wins on everything.
The short version
- Direct sunlight — reflective glass is the strongest performer, then tinted, then plain float. Double and triple units are the weakest here on their own.
- Indirect solar heat — triple glass leads, then double. This is the heat that arrives without the sun shining straight in.
- Noise — only double and triple units do anything meaningful. A single pane of any tint does not.
- Safety — toughened glass, and nothing else.
That is the whole trade-off in four lines. A west-facing living room in Lucknow has a different problem from a bedroom on a main road, and they need different glass.
Why double glazing is not the answer to glare
This surprises people. A double-glazed unit is excellent at indirect heat and good at noise, but on its own it does very little about direct sunlight streaming through a west window — the light still comes straight through two clear panes.
The fix is to combine. The catalogue puts it plainly: for a room that gets both direct sun and ambient heat, use reflective glass on the outer pane and normal glass on the inner pane of a double-glazed unit. You get the reflective coating working on the sun and the sealed cavity working on the heat and the noise.
What the frame has to allow
Glass choice is only real if the system can hold it. Across the Winkraft uPVC range the internal glazing options run:
- 4 mm single to 36 mm triple on Casement Windows, Tilt N Turn Windows and most of the door range
- 4 mm single to 22 mm double on Sliding Windows and the vertical slider
So if you have settled on a triple unit, that rules out the sliding window in the same opening. Decide the glass and the system together, not one after the other.
Noise, honestly
Winkraft systems use a multi-chambered profile with double seal technology, and the catalogue states that sound reductions up to 40 dB are achievable with appropriate glazing. Read the last three words carefully. 40 dB is the system working at its best with the right glass — it is not what a single-glazed casement will give you.
For context, 40 dB is roughly the difference between a busy road and a quiet room. It is a large reduction. It also requires the double or triple unit, correctly installed, with the seals doing their job.
Heat
The same qualification applies to thermal numbers. The TwinSash system can reach as low as 0.8 W/m²K using double glazed units. That is a genuinely good figure. It is also a figure for a specific system with specific glass, not a blanket claim about uPVC.
What to actually do
1. Work out which problem you are solving in each room — sun, heat, noise, or safety. Usually it is one, occasionally two.
2. Pick the glass for that problem.
3. Check the system you want can take that thickness.
4. For anything at low level, near a stair, or in a door leaf, use toughened regardless.
If you would rather not do this room by room, send us the plan. We will mark up a glass specification against each opening and return it with the window schedule — there is no charge for that, and it takes the guesswork out.