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Insulation: Housing

Volume 481: debated on Thursday 23 October 2008

To ask the Secretary of State for Environment, Food and Rural Affairs if he will place in the Library the details of the assumptions behind his policy on encouraging savings in household bills from home insulation. (224512)

I have been asked to reply.

The assumptions behind Government policy are based on the findings of the two following reports, both of which are available on the website of the Department for Environment, Food and Rural Affairs:

“Measurement of energy savings and comfort levels in houses receiving insulation upgrades”, Martin and Watson, Energy Monitoring Company, June 2006.

“Review of Differences between Measured and Theoretical Energy Savings for Insulation Measures”, Sanders and Phillipson, Centre for Research on Indoor Climate and Health, December 2006.

Assumptions from these reports have been used to update the Building Research Establishment's BREDEM model for domestic energy usage and to calculate energy savings for the following measures.

The energy savings were converted into cost savings for a standard three-bedroom semi-detached house with gas-dominated heating on a standard heating pattern and energy pricing assumed a price of 3.8p per kWh of energy saved for gas and 13p per kWh for electricity, based on consumer tariffs available in September 2008.

Illustrative value of core measures and annual energy bill savings


Cavity wall insulation

Loft insulation (from empty)

Loft insulation (top-up)

Estimated installation costs1




Annual fuel bill savings per household




1 Estimated average overall installation costs to consumer and energy supplier under Carbon Emissions Reduction Target scheme, as published by the Energy Saving Trust.