Pin away, Tony! I've wanted this since I was a teenager, and it was hard work to get here (had to build a new kitchen first), so I feel I deserve it. Yes, it is insulated. The wall and roof panels are stud wall construction with timber frames, Stirling board outside and MDF inside. The sandwich contains 5 cm foil-backed foam insulation, plus one layer of silver bubble-wrap stuff for good measure. I intend to keep it organised....!