Iceverge

Hi Hastings, What a lovely project. What is the maximum depth you are prepared to loose from the room? It sounds similar to the Green Building Store retrofit of Stirley farm and I believe MBC have completed a similar project if you look through their facebook photos. They lost a lot of floor space however. How sound are the external walls? Might they be able to take a perimeter ring beam bolted to the stone with compacfoam or similar to create a thermal break? The joists could be hung from this and the external walls then internally insulated (carefully) with a breathable insulation like wood-fiber or lime hemp?