How did you fix your boiling hot house?

[Octonaut4Life]

The upstairs rooms at the back of our house are boiling, boiling hot in the summer, which is a bit of an issue as our toddler now sleeps in one. Neither have excessively big windows and we have black out blinds up on them to keep the light out but they get so hot and they cool down incredibly slowly even once it's dark and significantly cooler outside. We're in 1920's ish mid terrace house.

Have thought about trying to put air conditioning in but I don't think the toddler's room would be suitable, because there's barely any external wall you could have the outside part on. Plus it's expensive and I don't really understand why the rooms get so hot in the first place.

I don't think the attic is particularly well insulated so have wondered whether improving the insulation up there would help. But really looking for any tips/thoughts and anyone who has a similarly hot upstairs who has managed to fix it!

Would an awning, shading the window from outside, help?

Do you keep your curtains closed during the day? And your windows? That should help stop them heating up quite so much.

Insulation would help as long as the room doesn't get too hot in the first place.
Windows, blinds etc must be closed until its cooler outside than inside.
If the room gets hot though, the Insulation will keep it hot.
Awning is a good idea.

Heat deflecting film on the windows has helped more than I expected. We ordered cut-to-size pieces from an online company, not cheap but not hideously expensive either. Not fun to fit, you can have it externally or internally and obviously internal is way easier, even a light breeze makes it a nightmare outside! It's supposed to work slightly better on the outside but having tried both (only the first window we attempted was done externally 😊) the difference really isn't noticeable, and certainly not enough to warrant the effort involved in battling the elements. The whole back of our house gets the sun from lunchtime til evening in the summer and makes it unbearably hot, we've built a sort of veranda/lean-to to shade the downstairs windows and used the film upstairs and it's loads better now.

Just get a portable air con machine.

You can get free standing Aircon things

These are amazing!

We literally don't open the curtains at all, all day and we have both curtains and blinds to keep the sun out and it's still roasting in there!

I actually think an awning could be a great idea although no idea how practical it would be to fit one - has anyone done this on an upstairs window?

The film sounds like a great idea too, thank you - will look into that!

how old is your roof?
we noticed a huge difference in how hot our house got in summer the year after we had the whole roof replaced - the old tiles were trapping and absorbing a lot of heat. the new tiles reflect a lot more, and a bit more insulation helped too.

we also installed windows with integrated aluminium blinds (the blinds are sandwiched between the double glazing glass which means they don't get dusty) which reflect a huge amount.

Our roof is pretty old I think so that's a good point. I don't think I'd appreciated how big a part the roof and loft space might be playing in heating up the rooms...

We had our loft triple insulated last year what a difference!

Also put roof vents in our sun backed south facing back bedroom roof.

I've also grown a wisteria all over the back of the house and that does keep the heat out too

OP, you seem to be ignoring the obvious solution mentioned above - a free-standing air con unit. These do not need an external wall. They just need to stand near a window.

As per @OnMyWayToSenility , insulate the loft properly and add a few vents on either side.
Also it’s better to stop the sun hitting the window rather than trying to stop the heat radiating into the room with a curtain. An awning would do this, though are prone to wind damage. Wooden hinged external shutters would work.
You could also consider changing the window sealed units for the reflective type.

I'm not ignoring it, I'd just rather think about what we can do to solve the problem rather than just plastering over the top with air conditioning. I think we probably will look at getting a freestanding unit but it will be a total pain to store when it's not in use, the house isn't very big and we don't have much storage space - I'm really focused on what we can do to reduce it getting so hot in the first place if possible.

Presumably you don't have the heating on in that room or the room below?

@Irrelevantdata
I am interested in the film
does it block out light / view?
would you mind linking to the product you used?

A new roof and new thick modern insulation (Kingspan) helped our loft rooms enormously. They are now warmer in the winter and cooler in the summer - I’d say about 50% difference.

If the weather hits 35 degrees then yes it is still hot up there and we use a column fan (and the DC cuddles a freezer block in a pillowcase!) but at least it’s bearable rather than inhumane.

By the way if you did want built in air con you can get a split unit where the inside bit can be some distance from the outside bit, as long as you can run a slim pipe and cable between them.

The light reflective film sounds interesting. Is it a mirror finish? We’d have to avoid that as it would dazzle the neighbours.

What ever you do, don't use tin foil to reflect! Someone suggested this to us with our baking hot house and although it was great at keeping the heat out... it cracked one of our windows as it got so very very hot!

We haven't come up with a solution yet but have been looking at external roller blinds.

The light reflective film sounds interesting. Is it a mirror finish? We’d have to avoid that as it would dazzle the neighbours

No, the one we chose isn't mirror finish, you can't tell it's there from either in or outside.

No, not really any noticeable reduction in light or visibility, think it technically lets something like 65% light through but the rooms don't feel dark and we don't spend much time upstairs during the day anyway so the reduction in heat matters more than losing a bit of light if that makes sense. For some reason I haven't been able to post links since the MN 'upgrade' but the company is Purlfrost, just type heat rejection film into the search function and the different types will come up.

Outside wooden shutters a good suggestion. After all its what they do in hot countries. Less likely to suffer in windy weather than an awning.

Sleep in the garden.

You definitely want exterior shading to stop the heat hitting the windows in the first place. With interior blinds the heat gets trapped between the blind and window and still heats the room.

Either an awning, shutters, a pergola with plants, or a cheaper option might be a sail although this is harder to take up and down than an awning.

@Irrelevantdata
Thank you !
My kitchen gets very hot in the afternoons. I would like to keep the light though to see what I’m doing

Our kitchen is the same, and the size of a shoebox which really doesn't help! We have the lean-to/veranda thing I mentioned shading that window now and I would say it's a similar level of light loss to the film, it just dulls the glare to something like bearable