UCL Energy Institute


UCL researchers collaborate with Islington Borough Council on the retrofitting of social housing

18 August 2023

Islington's social housing stock appraised for retrofitting using the 3DStock method

Image of council blocks seen through an old window

A team in the Building Stock Laboratory have developed a detailed plan to get the social housing stock of the Borough of Islington in London to net zero carbon emissions.

This stock is very diverse in form, age, and construction, and includes houses, flats, and maisonettes. A total of 4500 buildings containing some 33,300 dwellings were modelled using the 3DStock method (3DStock is a method for modelling all buildings – domestic, non-domestic and mixed-use – in a locality, in three dimensions and located geographically). Each dwelling was examined and measured separately: the modelling did not rely on 'archetypes' as in many such studies. Realistic retrofit options were analysed in each case, using current cost data from practitioners.

Six packages of measures combining fabric improvements, heat pumps, and photovoltaic installations were evaluated for every house and flat, in terms of costs, the impacts on gas and electricity use, and predicted cuts in carbon emissions.

The roll-out of measures between 2020 and 2030 was modelled with a specially developed scenario tool, allowing the user to set different criteria and priorities. Fabric measures on their own were shown to achieve only a 13% cut in gas use on average. Heat pumps are the key to displacing gas use. With all measures combined and taking account of the predicted decarbonisation of electricity supply, it is only possible to achieve an overall 70% cut in emissions by 2030.

Stephen Evans, Daniel Godoy-Shimizu, Philip Steadman, Shyam Amrith, Dominic Humphrey and Paul Ruyssevelt carried out the project for the London Borough of Islington. The work is reported in a recent paper in 'Buildings and Cities'. 



Image credit: iStock