Kilowatt House is a Grade II listed house built in 1938 for the acoustic engineer Anthony Greenhill as an experimental laboratory for his sound experiments. Designed by architect Mollie Taylor., it is an unusual example of Modern Movement architecture in Bath. By the 1990s it was abandoned and had fallen into disrepair. It was refurbished in the early 2000s, but the work failed to address the issues of moisture and insulation, so it is cold, expensive to heat and suffers from condensation and damp.
We were approached by the new owners to help them with a whole-house retrofit which includes replacing all the single glazed Crittall windows with double glazed, insulating the walls and roof and installing a mechanical ventilation system (MVHR). Due to the listing it is not possible to insulate externally, so 80mm of insulating plaster and wood-fibre are being added to the insides of the in-situ concrete walls, and insulating plaster is being returned into the window reveals to reduce thermal bridging around the windows.
Adding internal insulation can cause moisture to be trapped in the walls, so the details were developed with building engineering consultants Greengauge who carried out calculations to determine the moisture risk of various options. The materials used are highly vapour permeable to encourage moisture out.
Work is due to be completed in Autumn 2023.
