The cost of retrofitting to PassivHaus standards: Three case studies of UK pre-1919 houses

The aim of this paper is to analyse the cost of retrofitting the UK’s pre-1919 housing to PassivHaus standards. This will help designers, clients and contractors to better assess the cost implications of refurbishing to such a high standard of energy efficiency and ensure better replicability of this particular approach to retrofitting if viable. The paper analyses the costs of three different real life case studies from the UK Government’s ‘Retrofit for the Future’ programme. In order to compare like for like, all three proposals will be assessed with energy data from identical software (PHPP and SAP). All costs are from cost consultants data and taken from the actual delivered works. In conclusion, the study seeks to assess the actual price for achieving a true PassivHaus retrofit, if it is economically and technically viable, and if any alternative options could be acceptable both in term of cost and energy demand.