

Question about insulating this.
Hi guys I'm reading so much different information I'm not sure which is the best way.
I've been searching through this group and going on YouTube, Google , Chat gpt etc and I'm just reading so much information that's different, even the AI bots are contradicting themselves lol
We bought this for a summer house and it was installed recently.
So now I'm looking at insulating it but reading so many conflicting answers.
Some say totally fill the 75mm void with 75mm thick PIR insulation and some say buy 50mm PIR and leave a 25mm ventilation gap behind it.
The website listing for the summer house says it has a breathable vapour barrier between the outside composite cladding and the wood.
Can someone tell me for certain which method is best and would the roof be the same way as well.
If I do leave a ventilation gap behind the PIR where will the air circulate?
Won't it just be trapped in the frame or do I drill holes to allow air to flow up into the roof and out ?
Thanks.
EDIT. it will be used mainly in the evening for no more than 3-4 hours as a relaxing space.