Existing walls are generally 350mm Cotswold stone any external insulation system would be unacceptable to the planning authority in a conservation area.
Walls have been upgraded by the application of a plasterboard laminate total thickness 92 .5mm giving a U value of 0.22 w/sqm k. This standard is somewhat better than that required by current building regulations. There are relatively small areas of external wall, particularly around window and door jambs and reveals, where this level of insulation can not be maintained using conventional products. The use of Proctors Spacetherm would have been a good way to deal with these isolated "cold bridge" areas. Unfortunately this product is still extreemly expensive and as a compromise the jamb areas were insulated with a reduced thickness of Kingspan Insulation.
Existing irregular thickness 50mm - 90mm rough stone floors were stripped out. A new sand bed was layed and then Underfloor heating pipes fixed to reinfocing mesh laid on 110mm Kingspan insulation. A concrete slab was laid on this and the original stone floor was re laid after cutting back the stone to 40 - 50 mm thickness.
