trend for lots of glass in hotter summers

[Hadtocomment]

Was wondering about the trend for big glass walls/huge picture windows or glass sliding doors now that the UK seems to be hotting up a lot. This summer was unbearable where I was for a portion of the time. Does anyone have a property with lots of glass like above and how does it affect things in terms of heat/cold? Often I find properties for sale talk only in terms of heating (as in the keeping warm elements) not in terms of how easy it is to cool also?

I'm surprised no one has replied to this! I'm very interested too as we are planning a large glazed extension facing south and I'm more concerned about overheating than heating. It's a tricky balance.

For anyone who didn't overheat in the hot weather this summer, please let us know what glazing you used. Thank you.

We have large windows and roof lantern. It’s some sort of thermal glass which stops the room getting too unbearable in sunshine. I can’t remember what it is called but it works well.

Our last home had a large conservatory type sunroom as part of an open plan extension. It was tinted and made by a specialist American company, but it could make the place unbearably hot in a heat wave, and wasn’t especially great at keeping heat in the winter. I would be very mindful of it in future house moves, as lovely as it was for most of the time.

Thanks so much for everyone's replies on this. I didn't know there were different sorts of glass for this sort of thing. Very interesting.

An awning that will shade windows from direct sunlight will cut down on temperature a lot.

I had a look to see if I could find out the name of the glass used. Sadly I failed, but it’s the same glass that is used in those architect built all glass houses if that helps. For the amount we needed it was a few hundred more but absolutely worth it to have a lot of glass and be able to use the room year round. Hope that helps!

It's a very good question OP. We have a large glass roof section in our open-plan kitchen/living/dining room and this summer it's been a fucking nightmare, as it faces southwest! We're in the process of having (very expensive), thermal blinds fitted that should help to mitigate its effects in future summers, but I would honestly recommend to anyone building a house in future NOT to have huge expanses of glass as it costs a fortune to fit them with the kind of blinds that keep out heat and light in summer. With heating bills going up so much too, it's also worth considering how much heat you lose through glass roofs, windows and doors in winter. The only answer is thermal blinds, but they're ££££.

I have a huge amount of glazing on the one end of my house facing the garden. It gets direct sunlight all morning. The sliding doors downstairs are fine and the kitchen is only unbearably hot when it’s very hot - think above 30 degrees. It cools down nicely if I open all the doors and the kitchen back door so a breeze can blow through. Upstairs we have a huge sliding glass door in the main bedroom and that gets way too hot. I close the curtains on very hot days and have looked into getting a film fitted which cuts down on the heat it reflects in.

We have this fancy Pilkington blue glass in our conservatory, lantern roof,it doesn't work. Our conservatory is north facing,it reached 44c, this summer, but it frequently does. We had opaque glass fitted both ends in the windows,no openings,as advised by the boss of the company,we had used before for all our windows and doors. She assured us it would stop glare and heat,it does neither! Only thing it's good for is privacy. We have kookaburra shades on the roof. The conservatory was 25 years old lean to with plastic roof, which was leaking,so we had new doors, windows, unfortunately then,my previous blinds didn't fit anymore. It's well insulated,heated and used all year. Read the government are restricting the usage of glass in homes because of climate change. We have a portable air conditioner unit,and an air cooler.solar panels fitted recently, trying to future proof.

We have thick double glazing (I can't remember the exact details, but it was more than twice as thick an air gap as the legal minimum at the time, 15 years ago) on the extension going across the back of the house. The width is floor to ceiling glass for 2/3, and the remaining 1/3 is ceiling to hip height glass, which goes around the corner another 3 feet, back faces south. The roof is tiled with just 2 large velux rooflight windows.

We (finally) put in blinds last winter and they actually made a big difference in keeping the heat out over the summer by keeping them closed in the daytime. We open the velux windows to let heat out that gets trapped in the ceiling.

And we also found that by keeping the windows/curtains closed at the back (south facing) in daytime, but opening windows at the front (north facing) once the very early morning sun had moved off, especially windows up higher in the house - upstairs and in the attic (and leaving internal doors open throughout house), facilitated air flow through the house and heat escaping out the top. Cooler air was sucked in from the shaded side to replace the hot air going out at the top.

It definitely is a problem if you face S or W. Not so much with N or E.

We are S facing, have lots of glass. We have done lots of these tricks. We have triple glazed, solar control glass. Top spec. Opening skylight for ventilation. Awning over the big sliding doors (but it doesn’t shade our picture window or two skylights). We do all the stuff about closing S facing until it’s cooler and opening N facing and roof.

Despite all this, we still overheat at the back when it’s above 30 degrees for more than a day or two. Neighbours’ house without all the glass is a lot cooler. (Although also much darker).

When we put all the glass in, going above 30 happened maybe once a year for a few days. No biggie. Now it’s several weeks a year!! Tbh we would probably have made slightly different design decisions with the current heat levels.

We are south facing with a lot of glass in our extension. It doesn't get hot until late in the afternoon as it is shaded by big trees in the summer. I think the only answer is external shading of some sort e.g trees, awnngs or external blinds. We also have honeycomb blinds internally but these don't seem to help much and feel like radiators in the late afternoon.

You could also incorporate a Brise Soleil into your design.
This is an angled set of louvres set above the glazing. Properly designed they will screen high summer sun but allow light from lower winter sun enter the room

You beat me to it. Planning are very concerned about the overheating effect architecture are working on it now . www.gov.uk/government/publications/overheating-approved-document-o

I was checking out shutters the other week

My mum and dad have bifolds and glazed roof in a new build which is very well insulated and they struggled to keep it cool and to get the heat out. They struggle to keep it cool in the winter too which is good! It’s very warm to say the least. South facing to. Have blinds and voiles to try and keep the sun out helped a bit.

We have lots of South facing glass. We specified low emissivity windows with a mid pane u value of 1.0. We also have extra large overhangs which protect from the overhead midday sun in summer but allow the low winter sun in. We have no east or west facing glass. Our house is also massively insulated 2x to 3x current building regs. We had absolutely no problem at any time this summer and we're in the SW.

We have a glass open orangery kinda think and it’s been unbearably hit because of it!!! admittedly I don’t have any blind/curtain but I will do next summer for keeping heat out opposed to in.

My late mum went to university in the south of France in the 60s and I remember her saying one of the departments had been designed by a modernist architect, it was all glass and unbearable over there from May onwards. I’d be cautious about lots of glass, unless it was insulating glass.

Not modern style, but our house has wall to wall windows.

It's like a greenhouse in summer. Unbearable to the point that we ended up escaping to parents houses this summer during the day. It's also harder to keep warm in winter. I don't see any benefit beyond it looking pretty personally!

They're also looking at building with big overhangs so we'll be shopping for rocking chairs and enjoying verandahs in the future

A friend had an extension built one and a half walls of bi-folds but they have a massive overhang so you can open up the kitchen and still dine undercover. It helps with the heat.

We went to a beautiful new visitor centre in Wales in Aug, three sides glass. We lasted 2 minutes, the temperature inside was unbearable.

I have big sliders that face SW on the back of my house. I made a large external curtain (flat) from white thermal blackout lining. Worked a treat. We really need the type of shutters you find in Europe but prices here are far too high currently.

Think I'd find a carpenter for shutters our windows aren't standard.

We've got a lantern roof and 3 sets of big bifolds on our extension. It faces north so is warm in the morning but cools by the afternoon.