Old Highland steadings are built to the standard width of the maximum unsupported span of a pine beam – about 5.7m– and supported by solid stone walls up to 1m thick. so, other than the chimney wall between the two wings, there are no internal load-bearing walls. We took out most of the 20^th century sub-divisions and the boxing around the main stairs, opening up the whole kitchen area. We also removed all existing internal wall finishes and claddings, exposing the original surface.

We then created an insulated shell inside these walls, providing an air gap, then solid insulation, with a breathable membrane, plaster board sheeting and a plaster skim. For the internal finish, we used the period practice of rounding the plaster corners of walls at all corners and apertures, replicating the appearance of the original walls. Modern internal partitions which would have had no analogue in the original building have been left with hard edges, making it easier to read the history of the building. In stripping off the previous wall cladding, we discovered two presses – cupboards built in to the walls – and have incorporated these in our redesign.  In the new living room – the original hay loft – we have, for aesthetic reasons, left exposed the original stone wall on the south-facing wall, where there is the greatest potential for net solar gain. Here we have have replaced brickbat patching with original stone recycled from elsewhere in the property and have fully repointed the stonework here using lime mortar. Overall U-values for the walls as built are .21 to .23W/m²k, against a regulatory target of 0.7W/m²k for buildings where there are significant constraints on what can be done (in our case, those of the house being an historic and listed building).