The installation was easy and by doing this myself I've shaved 2/3 thirds of the overall cost of this build. Shame to cover it all up...
This essentially consisted of several inches of heat reflecting foam insulation in the roof and floor and standard loft insulation in the walls, all picked up at my local DIY store. Every inch is also sealed in a weather membrane and I've coated the exterior in more weatherproofing paint. The actual building was also pressure treated.
All of this is really just to reflect as much heat as possible during the summer, otherwise I've got myself a human oven.