I know there’s info on line for how to DIY but this way there’s no debate on warranty.

Really interested to find out how far you can get effectively with the A2W and cooling.

I am looking forward to get the heatpump to cool. Perhaps run it as cold as possible in the large rad (in the part of the house with pipework hidden under concrete floor). Place a bucket to collect the water from under it + we may need a de-humidifier...

We are also planning an awning to reduce solar exposure in the south facing side. 

Perhaps the other tactic will be shutters on the windows. 

And of course fit an a2a system for the bedrooms...

Trying to sleep when it is too hot is a torture. I ended up getting used to the box fan. 

Info from someone who sells the stuff as a kind of reference to back up the claim.

https://www.lustalux.co.uk/resources/does-window-film-damage-glass

You'll see other sources regard the risk higher but it's strangely enough people who sell film that think the risk is low and people who sell shading that think it's higher 8)

I've had a genuine velux roof window crack after fitting solar control film on the inside. That was several years ago and the first hot sunny day after installing it. Meanwhile three others with non velux double glazed units and also the replacement unit for the one which cracked were all filmed with the same film and no issues since.

As i work as window and door repairs, I know there's a recall notice for some velux units due to spontaneous cracking in cold conditions and there's plenty which aren't on the list that have also shattered for no apparent reason.If you have a velux with genuine glass, don't add a reflective film.

Since the film worked, but not enough for keeping the bedroom cool enough, I added one of the anti heat awning blinds and that's made a big difference.

https://www.veluxblindsdirect.co.uk/products/awning-blinds

Up until the last hair dryer session, it never got hot enough in our house to be an issue. The oldest bit has massive thermal mass. The less old part, slightly better. The newest part is modern and we don't sleep in that anyway.

This time, even our bedroom got too hot at night - something like 26 degrees C. Trouble is, once hot, it doesn't shed the heat quickly.

So, we started leaving the tilt and turn doors in our bedroom open until .... the juvenile bats who live in the soffits seemed to lose their sat nav capability and started to get in through the tilt and turns! Luckily, only the odd one or two. We estimate about fifty bats share our home with us at this time of year and would prefer it if they stayed in their own bedroom and didn't come into ours.

And carbon neutral. Pity about the particulates but otherwise good.