As the owner of a late Victorian semi-detached house in a conservation zone I have been reading Robert Prewett’s Passivhaus Diaries, regarding the conversion of 64 Midmoor Road to a low-energy building, with great interest (4 March, page 42)

However, what has been lacking from these reports is any financial information such as the cost of the work and, perhaps more importantly, cost benefit and payback figures. Can we have one more contribution from Mr Prewett with this information please?

John Medlock, managing director, Axter

Readers can find capital cost data and payback times detailed in the article Refurb: Comparing Passivhaus and Decent Homes, which is on the online archive at