People Powered Retrofit were asked to carry out a survey and retrofit options study of a ‘typical’ home in Letchworth. More information about the study is provided below, with a link to the full report for further reading.

About the ‘typical’ home

The house studied was unoccupied at the time of survey, awaiting refurbishment works. It is very typical of some of the older homes in Letchworth in style and layout. It is 2 storeys with 3 bedrooms and an external rough render finish. It has a minimal level of existing insulation – with some loft insulation and older double-glazed windows. It has a gas based heating system with a newer boiler and many radiators have been replaced relatively recently. The main electrical installations have been kept up to date – with a relatively modern large capacity consumer unit in place, so adding a heat pump or PVs should be very possible without major electrical upgrade works.

An air pressure test demonstrated that the house has a reasonable level of existing airtightness, well within the current backstop for new-build building regulations. Other homes may vary, but the study found it is common for older homes to be a lot more air-tight than is often assumed.

The study home’s current space heating demand per square meter is a little above the UK average – so in its current condition it would be relatively expensive to keep warm. However as a smaller home it’s total heat loss is low and it would be able to accommodate a medium-sized air source heat pump.

The scenarios in the following report have been developed to test a range of options – variously prioritising carbon, comfort or cost.