How do you recognise single, double or high-efficiency glazing?
Want to know if your windows are eligible for an upgrade to high-efficiency glass? Or do you want the existing windows in your home replaced?
Then, first, it is important to know what type of glass is in your windows today.
At Group Ceyssens, we focus entirely on total renovations where the existing window profiles are retained and only the glass is replaced. Therefore, we do not do window profile modifications or replacements. To get every project off to a good start, we begin with a thorough analysis of the existing situation. That way, we know exactly what is possible and how to achieve the best result.
With a few simple checks, you can already find out what type of glass is currently in your windows and whether your project fits our approach.
Single or double glazing? You can often see the difference immediately
Look at the side of the window first. Do you see one sheet of glass? Then you have single glazing. If you see two panes of glass with a small space between them, it is double-glazing or high-efficiency glass. Those two glass layers are separated by a spacer, often an aluminium, plastic or Polymer (= Super Spacer Edgetech; high thermal properties tailored to current and future insulation standards) edge that seals the space between the glass panes.Note the markings in the profile
There is usually a spacer between the glass layers. It often has technical information printed on it, such as:- the name of the glass producer
- the year of production
- an indication of the type of glass, such as HR, HR+ or HR++ Some manufacturers even provide a unique code referring to the technical specifications of the glass. Useful if you want to know exactly what's in the window.
The 'lighter trick': a visual test
A simple way to check the type of glass is with a lit lighter (or match). Hold the flame close to the window and look at the reflections in the glass at an angle:- 2 flames? → Single glass
- 4 flames? → Double or high-efficiency glass
- All the same colour? → Double glazing
- One of the flames has a different colour (e.g. blue or purple)? → High-efficiency coated glass That coating ensures better thermal performance - a subtle colour difference that therefore says a lot.
An Overview
| Glass type | How to recognise? | What does it mean? |
|---|---|---|
| Single glazing | One glass pane | Minimal insulation, energy costs are higher |
| Double glazing | Two panes, same reflection colours | Better insulation, traditionally common |
| HR / HR++ glass | Four reflections, different colour | High insulation thanks to coating and gas filling |
| Low-E | Subtle colour effects, cool to the touch | Extra thermal comfort – like a glass shield for your home |