Retrofitting existing housing: How far, how much?

The significance of retrofitting the existing housing stock is considered for the policy commitment of delivering an 80% CO2 emission reduction by 2050. Background issues of energy, legislation, potential and actual CO 2 savings, socio-economics (payback, fuel poverty, health impacts, employment stimulus, etc.) are discussed. Different potential retrofit strategies for the housing stock are presented. Three large-scale housing retrofit programmes in Wales, UK, are analysed for energy savings (using the Energy and Environmental Prediction Model), CO2 reduction and costs. Two whole house retrofit projects in Wales are also assessed, one of which has been the subject of long-term monitoring. Data are compared on a range of retrofit options: different strategies (elemental, multiple and whole-house measures), costs, actual CO2 reductions and associated benefits. The findings indicate that as the cost of measures rise in relation to the predicted savings, reasonable paybacks will be difficult to achieve, particularly for finance packages such as the Green Deal. There are funding opportunities for installing shallow elemental measures to reduce CO2 emissions by 10-30%. However, the large-scale financing of deep (60-80% reductions) whole-house packages of measures is not currently available and does not pay back.