Nottingham City Council has used the Dutch ‘Energiesprong’ technique to upgrade the energy efficiency of 155 of its social housing units.
Energiesprong is a business model that allows blocks of social housing to be retrofitted, en masse, to a guaranteed standard of energy efficiency and comfort. The guarantee lasts for 30 years, with the local authority getting its initial outlay back through savings on maintenance and tenant energy plan payments.
Because it treats the whole house in one go, fitting external walls and roof cladding that are made off-site, tenants don’t have to move out, and there is an agreed completion time.
In the Nottingham scheme, monthly energy bills have dropped from about £120 to £65, and there has been an 86% reduction in carbon emissions. One of the tenants, Joan Warburton, said her previously cold and damp bungalow was now transformed:
It’s made a lot of difference. It’s warmer. I don’t need my dressing gown now. All the draughts have gone. Before it [the home] looked like a rabbit hutch – it looks like a proper home now.
Portsmouth has around 16 000 social housing units; about one fifth of the total number of homes in the city.
Wilmcote House, Portsmouth
Portsmouth City Council intensively retrofitted 113 dwellings in the 11 storey tower block Wilmcote House with external wall insulation, triple glazing and energy efficiency measures.
Before the retrofit, one-third of tenants reported issues of damp, mould growth and draughty windows. Residents also found the heating very expensive to run so often tended to only heat one room and stay in there.
Since the retrofit, tenant energy bills have fallen by an average of £700 a year, whilst flat temperatures are significantly higher. Carbon savings worked out at roughly 2 tonnes of Co2e per resident per year.