Triple Glazing in an extension

mrsWhippy

Hi,

We're going to be undertaking an extension on an old cottage this summer - extension will be about 30sq.m and will contain a lot of glazing, on the s/w corner.

We were wondering would it make sense to pay the extra to install triple glazing here when the rest of the house is actually quite cold. We will be tackling the remainder of the house somewhat but it's still going to be colder and draughtier than the extension. Are we going to be losing the benefits of triple glazing if the rest of the house is a heat sink?

Cheers

KenjiOdo

Should I look to install triple glazed windows?
Triple glazed windows are typically more energy efficient than double-glazed windows and can achieve a U-value as low as 0.6 W/m2K versus a U-value for a good double-glazed window of 1.2 W/m2K. However, triple-glazed windows are typically considerably more expensive than double-glazed windows.

For this reason, investing in triple glazed windows is more suited to a situation where there is a high level of insulation, e.g. new builds or refurbishments with a very good Building Energy Rating, i.e. an A-rating. This is because if a house has a lower level of insulation, the investment in triple glazed windows with a low U-value would not be cost effective as heat retained would be lost through the other fabric elements of the house.

- See more at: http://www.seai.ie/Power_of_One/FAQ/Windows/Should_I_look_to_install_triple_glazed_windows.html#sthash.qpcFK0lA.dpuf

Old discussion from 2011 on boards.ie; prices have probably jumped considerably since then.

mrsWhippy

Thanks.

The triple glazed u-values we're looking at average 0.82 W/m2K, installed, and the price difference is only 10% more than 1.2 W/m2K double glazing from the same manufacturer.

So in that instance, would you bother with triple glazed? It totals an extra 1k over the double glazed. The remainder of the extension will be well insulated (200mm eco-bead) and there will be doors separating the house from the extension....

It's hard to know. I know we'll also be losing a lot of the solar gain benefits too however.

HPT

mrsWhippy wrote: »

I know we'll also be losing a lot of the solar gain benefits too however.

That's news to me and I'm disappointed to hear it because I currently get the benefit of the sun heating up the rooms at the back of my house from April to September. It usually brings the inside temp to at least 20/22 degrees. I only have double glazing and I've no idea what spec it is but I would upgrade to triple glazed as long as I'd still get a decent bit of free heat from the sun.


My brother upgraded from double to triple glazing and we noticed a major reduction in noise from outside. He lives in a quiet Dublin suburb but the difference was remarkable.

KenjiOdo

HPT wrote: »

My brother upgraded from double to triple glazing and we noticed a major reduction in noise from outside. He lives in a quiet Dublin suburb but the difference was remarkable.

I remember the upgrade of single pane to double, quite a significant noise reduction on good make windows. Some of the cheaper (thinner?) glazing didn't have the same magic. I think some of that was down to whats in between the panes. Some manufactured with a vacuum others with some sort of (inert/noble?) gasses?

@ OP I'm no expert on windows just thought I'd help out. But if the quality of the overall frame is the same and you afford to drop the extra €1k on them i'd say do it!

BryanF

HPT wrote: »

That's news to me and I'm disappointed to hear it because I currently get the benefit of the sun heating up the rooms at the back of my house from April to September. It usually brings the inside temp to at least 20/22 degrees. I only have double glazing and I've no idea what spec it is but I would upgrade to triple glazed as long as I'd still get a decent bit of free heat from the sun.

the reduction in solar gain is typically out weighed by the reduced heat loss. We're taking ~ 10% reductions
Forget that nonsense

murphaph

If it's only 10% more and there will be proportionally a lot of glazing then I would go triple glazed too.