UK Government targets aim to reduce national greenhouse gas emissions (from all uses) by 80 % by 2050 when compared to the position in 1990. Progress towards this target has already been made in the housing stock through improvements in energy efficiency. The average SAP rating (energy efficiency based on fuel costs) has risen, and CO₂ emissions have fallen. Significant further improvements, however, are required in the housing stock to meet the 2050 targets.

The results of the analysis of possible future energy efficiency scenarios for English housing are presented in the English Pilot Project report in terms of CO₂ and energy use. English Housing Survey (EHS) data from 2012 is used to calculate the potential for the installation of a number of energy efficiency improvements, and these improvements are applied in four scenarios representing 2050. The modelling which these scenarios are based on is the BRE Domestic Energy Model (BREDEM) and its derivative the UK Standard Assessment Procedure (SAP). Other factors such as population and emission factor changes have also been taken into account. Finally a modelled–to-real ratio has been calculated and applied to the scenarios to adjust notional emissions to be closer to the actual emissions.

Base modelling of the 2012 EHS data gave total CO₂ emissions to be 124Mt/year, this equates to approximately 5,700 kg of CO2 per household per year in England in 2012. Applying a modest improvement package lowered the CO₂ emissions by 34 % from 1990 levels. Two moderately ambitious scenarios both gave savings of approximately 50% from the baseline 1990 figure. The targets for 2050 are only met by the most ambitious scenario which saves 88% from 1990 levels.

In order to achieve the improvements to the residential stock required for the most ambitious scenario, increases in the number of improvements to the stock and changes to the market for measures such as solid wall insulation, heat pumps and alternative energy sources such as PV will be required. Increases to the rates of installation of these measures will be needed rapidly in order to meet the target required in the relatively short timescale.  It is possible that current rates of loft insulation, cavity wall insulation and double glazing will be sufficient if implementation of these measures continues to be encouraged by government incentives and legislation. Rapid increases in the number of other measures installed alongside these mainstream measures, such as solid wall insulation and heat pumps, are however essential to meet the overall targets.

Greater potential for savings exist in the single family homes and terraced homes, reflecting their prevalence in the stock, their current large contribution to CO₂ emissions, and greater potential to install a greater range of measures.