White window with its glazing and handle

Triple glazing, what really changes

Triple glazing uses three panes separated by two layers of insulating gas. Compared with double glazing it clearly cuts heat loss, reduces the cold feeling near the window and, in practice, is needed to get Klimabonus in Luxembourg. It is heavier and needs a frame designed to carry it.

Last updated: 31 October 2026

Double vs triple glazing

	Double glazing	Triple glazing
Number of panes	2	3
Thermal insulation	Good	Very good
Cold feeling near the glass	Possible in winter	Much reduced
Weight	Lighter	Heavier, needs a suitable frame
Klimabonus	Usually not	Yes, if the other conditions are met

What is a U-value? Ug and Uw explained

Ug measures the insulation of the glazing alone. The lower the value, the better.
Uw measures the insulation of the whole window: glazing, frame and spacer.
For Klimabonus, the 2026 scheme asks for Ug 0.6 and Uw 0.85 W/m²K or lower, with Uw calculated for a standard window of 1.23 × 1.48 m.

Glazing options

Warm edge spacer between the panes, to limit condensation at the edges.
Acoustic glass for noise reduction near a road, railway or the airport.
Laminated safety glass on the ground floor and for doors.
Solar control glass for large, very sunny glazed areas.

Triple glazing in summer

Good insulation works both ways. On large windows facing south or west, plan sun protection: external blinds to keep heat out or solar control glass.

Our advice

For a heated room in Luxembourg, choose triple glazing. It improves comfort all year round and it is the condition for Klimabonus windows. We check the certified values of every window in your quote.

Frequently asked questions

Is triple glazing worth it?

In Luxembourg, for a heated room, almost always. Double glazing can be enough for an unheated space such as a garage or shed.

Does triple glazing reduce noise better?

Not automatically. Noise reduction depends mostly on pane thickness and using panes of different thickness. Dedicated acoustic glass is the real answer near a busy road, a railway or the airport.

What U-value do I need for Klimabonus?

The 2026 scheme asks for glazing with a Ug of 0.6 W/m²K or lower and a window Uw of 0.85 W/m²K or lower for a standard window, on top of the other conditions.