Double Skin or Single Skin Blockwork for Garden Office and Gym? Information, help and advice on many architecture, self build and design problems and issues

[Butterpie]

I plan to build an office/gym at the bottom of the garden. It needs to be made of mainly non combustible material so was thinking breeze block.
If its approx 6m x 3.5m does it need to be double skin or can I use 1 skin of block plus piers, and use multifoil or kingspan then plasterboard?
Any advice would be much appreciated

Bp

[MarkGrogan]

I do not have any suggestions for you because I am personally looking out for ideas on materials needed to build a storage shed just behind my garden in the yard area. It does not have to be able to withstand massive weight, but it has to be durable enough to store tools and electronics. DIY is definitely better as it is cost-efficient and customisable too. Good luck with your project.

[welsh brickie]

You could use 150mm thick concrete blocks,to keep the internal space you can externally insulate the wall