Double Glazing / Triple Glazing / Something new

Triple glazing with self cleaning glass and remote opening/closing.

We replaced a very old and large (full room height and over 3m wide) window with triple glazing and it is the best money we’ve ever spent on the house. Granted the old window was blown in a few separate units but the noise reduction was staggering. We live on a main road and wished we’d done it with the other window upstairs that faces the road too. Think it was an extra 400 quid to get triple glazing, absolute no brainer as was only 1 window at the time.

Another option is to get bigger spec double glazing. Typical units are 24-28mm thick and use 4mm glass. We had some of ours replaced with 30mm units with 6mm planitherm on the inner panel and 6mm self cleaning on the outer panel. We also had the frames foam filled. It’s a surprising difference in noise and heat retention for very little cost difference.

Our windows are quite large at 2.6m*1.25m

Have a think about anti solar film/tint if you have any south facing windows, it can really help with preventing overheating in the summer, something which will sadly become more commonplace in the UK.

Extra thick double glazing with solar film sounds good. We don't live in a particularly noisy area but most of the house faces south. Triple glazing has weight issues as well as cost issues apparently and our house isn't that new so going high end double might make sense.

Any more advice welcome - brands, supplies near Southampton?

I think you'll find the 2x6 double glazing is about the same weight as 3x4 triple glazing.

We've had triple glazing for nearly ten years, yes it's heavy. Upsides are:

The deeper frames, easier to tie in with wall insulation and eliminate the thermal bridge around the frame.

Noise, it's good but not as good as phonic double glazing with a really thick outer pane and even some double glazing with two thick panes.

In terms of solar gain, you want that in Winter. A better solution for heat control is external shutters which keep you warm in winter and cool in Summer. Some UK houses had fake ones in the 70s, you need real one.

When I did it the best double glazing was uw 1.2 and triple was uw 0.9. I think you find that the best double equals the triple now. Compared with what you have you'll probably cut heat loss by 25% with either.

^ as Ed says, good shutters or curtains can help a lot with insulation and noise - but obvious downside is only when closed.

That said, and I am going off my old boss who had built multiple passive houses, one approach is triple glaze to the East, North and West, Double glaze to the south but with solar control in place and all windows to have external or internal shutters or windows.

x3 for solar gain in winter!

Significant uplift in £ on triple with minimal gains on thermal rating. Useful for sound insulation though. Better off with good quality double.

Very timely discussion for me. Thanks.
Not a noisy area for us so looks like double glazed at the top end with some extra effort put into the install. Imagine that is the same conclusion for many.

I’d suggest that for most people double glazing is the best cost / performance compromise.
You’re looking for 24mm units with argon fill, low E coating and warm edge perimeter bars. Easy clean is ok but only works if you’ve got sunshine and rainfall on it.
Triple glazing in say a 28mm unit works well with krypton gas (works better in the 2 smaller cavities) and the rest of the spec above.
For better g value, (solar gain) you need to get a clearer glass and that’s not as effective in in a triple glazed unit.
For noise reduction you’d be after a laminated glass, which is the thicker 6mm pieces referred to above I suspect.
There’s loads of options, something for everyone but not every window manufacturer will have all options and as with everything, you get picky the price will go up!
New windows generally have a more efficient frame as well, timber is a winner as it’s not yet more horrible plastic crap!

As a side note, you can get a massive performance upgrade in your windows just by replacing the glass for modern units. If it’s a pvc window that can be a simple diy job that costs you about £75/window and takes about 20minutes. A bit harder if wooden and possibly not a diy job unless you’re happy replacing beading but with a bit of woodworking skill, still a diy job.

Has anyone any experience of triple glazed units with larger spacings? The ones mentioned above are 28mm overall, so the gaps are small. There are 44mm overall ones available, but need deeper frames, so dearer I assume, but are they significantly better?
@Edukator - how thick (overall) are your units? And are they effective?

We have just had 40mm triple fitted and the difference is dramatic.
They replaced the units the other day (factory hasn't added the thermal tint to the originals supplied), when they took the units out there was about a 20° temp difference between the internal and external faces. Even the fitters were surprised.
We are getting the windows at the back done next year now as the sound deadening and temp effect is well worth it

I have 48mm spaced triple glazed. They are thermally very efficient and excellent at reducing noise. On a winters day you can’t feel any chill from the glass internally. Significantly better than a double glazed unit. Just as important as the window is installing it well making it air tight, in line with wall insulation and also insulating over at least part of the frame to prevent thermal bridging.