HR++ or triple glazing: what does it cost and when do you choose which?

What is the difference between HR++ and triple glazing?

HR++ glazing consists of two panes of glass with a coating and a gas fill between them. Triple glazing has three, and therefore two cavities. That makes it better insulating, but also thicker and heavier.

U-values are guide values for standard glass; the exact value is on the product data sheet. Prices are indications of typical market prices in 2026. Whether VAT is included varies by supplier; for a home over 10 years old it is usually 6% VAT, otherwise 21%. You will hear your exact price after a visit or in your quote, following the free consultation.

The lower the U-value, the less heat escapes through the glass. For comparison, single glazing has a U-value of about 5.8.

If you want triple-level insulation in a narrow or protected frame, vacuum glazing is an option: about 8 millimetres thick and as insulating as triple glazing, but considerably more expensive.

What does HR++ or triple glazing cost for a whole house?

As a worked example, take an average corner house with 22 m² of window. Replacing all the glass with HR++ costs about €4,700 there, before any grant is deducted.

Indication of typical prices in 2026, from public price overviews. The exact price follows after a visit or in your quote.

You usually have triple glazing fitted together with new windows. According to Dutch comparisons, windows with triple glazing are about 4.5 per cent more expensive to buy than with HR++ glazing. Suppliers sometimes quote a larger extra cost per m², so always ask for the difference in your quote.

New windows also mean work on the inside, such as finishing the reveals. We include that in the same schedule when you have your windows replaced.

How much do you save with HR++ or triple glazing?

The most if you still have single glazing. For a corner house with 22 m² of window, a Dutch calculation method gives this saving:

Worked example based on Dutch figures and a gas price of €1.37 per m³. In Belgium your saving depends on your own energy price. Payback time: our own division of €4,700 by the saving per year, without any grant.

That last column says a lot. Going from single to HR++ glazing, you earn the glass back in about 13 years. If you already have ordinary double glazing, it takes more than 52 years, and you are mainly choosing comfort: less cold near the window and less condensation inside.

Triple glazing keeps even more heat in, but also lets in less solar heat. On the shady side, the north, triple glazing is usually the best choice; on the sunny side it is a trade-off.

Glazing is one measure among several. In the usual order of return on insulation measures, HR++ glazing comes after cavity walls and the roof, but before the floor. If you want to tackle the whole house, start by having your home insulated: cavity, roof and floor.

Is triple glazing worth the extra cost?

That depends on your windows. If they are still in good condition and you only want better glass, HR++ is the logical choice: it usually fits in the existing frame, and triple glazing often does not.

If the windows are coming out anyway, triple glazing is definitely worth considering. You rarely replace windows, so the glass you choose now will be there for decades.

The same goes for large areas of glass. If you want to have a sliding door installed facing north, triple glazing is the logical choice; facing south it is a trade-off.

For insulating glass a grant is sometimes available, depending on your region. In Flanders it is the Mijn VerbouwPremie: since 1 March 2026 only income categories 3 and 4 still receive a grant for all works. Brussels has the Renolution grants and Wallonia the primes habitation. Check the current amounts and conditions with your region (for Flanders at vlaanderen.be) before you decide.

How do you have your glass or windows replaced by us?

If new glass goes into an existing wooden window, the glazing beads come out and go back in. We then paint those too: painting wooden window frames on the inside costs from €99.99 for 5 to 7 metres of frame. We do not paint PVC windows.

If the windows come out, the reveals have to be finished again. An example with our prices, as an assumption: 8 windows with a combined 12 m² of reveal and 40 metres of corner bead.

Prices from our 2026/2027 price list, valid from 1 September 2026. Prices exclude VAT.

The small-job surcharge of €249.99 no longer applies once the job is 50 m² or larger. If you have a few walls done in the same round, you do not pay that surcharge.

Request a quote or call us on weekdays between 9:00 and 17:00. Tell us the number of windows, the approximate sizes, the glass that is in them now and the year your home was built. In a free consultation we discuss glass and windows, and then you receive a plan and a quote.

If you agree, we take measurements and check the walls. The final price and schedule are then fixed, and we start on the day we agree together. You pay 50% on the first working day, once all materials are on site and we have started, and 50% on completion.

The glass and windows are replaced by our four own contractor teams of four people each; our 97 own tradespeople then do the finishing. For the whole house we also take on the complete renovation as a contractor. Exterior painting is always on request. We work throughout Belgium.