Yes Bruce, it all helps.
In general the original old walls are leaky, both air and dampness, even after my repair work. So hence me using thermal blocks that free stand on the raft foundation inside the old building.
But I need to keep the thermal blocks from touching the original old walls, and where they do, or get close to, I use a plastic separation membrane. I do not want pooling and dampness showing on the base of the new interior walls.
The wall plastic membrane, 1.5m high, is very carefully tucked behind the upward protruding raft foundation membrane. So any water that gets through the outer/original building wall, can therefore run down and under the raft foundation into the original sub soil/ground, like it has been doing the last 150 years.
The thermal block walls will reflect any heat inside, ie, the heat generated will stay inside.
The heating inside will be 3kW electric under floor heating using the concrete slab as a thermal mass, a storage heater. This works well in my other buildings, but, and in this modern world a big ....... But!, If the building is going to be used, the under floor heating must run at least 48 hours before.
There are lots of variables at play here, organic material adjoining brick, mud and straw walls, lime mortar and cracked brick walls. Hence me paying close attention to all details.
Each thermal block, 620mm x 250mm x 200mm, (approx., 24inch x 10inch x 8inch), weighs 23kg, (50lbs).
I must be getting older, as my arms ache at the end of the day.! ha ha !