Willmott Dixon has teamed up with the Building Research Establishment (BRE) on a project which will form an energy efficient blueprint for older properties.

In collaboration with Letchworth Garden City Heritage Foundation, Willmott Dixon and BRE are improving insulation and thermal performance of a 1920s semi-detached home in Letchworth.

The retrofitted Heritage Foundation-owned building will then be monitored for 12 months to check the difference in energy use and determine how much could be saved in energy costs.

Features of the work includes installing Pavadry wood fibre internal wall insulation, new windows, solar PV panels, a waste water heat recovery system and a demand controlled ventilation system from Aereco.


BRE previously assessed the house to model its baseline energy performance and gathered energy use data from typical homes in the area. Performance specification options were then developed for the Heritage Foundation in line with current government regulations for new homes and more ambitious carbon/energy reduction targets.

Once completed, the organisation will monitor the property to analyse energy use and internal conditions, the performance of various design features and the experience of the property's residents. Another similar property, without modifications, is being used as a comparison.

Willmott Dixon Re-Thinking's Rob Lambe said the project is important to ensure domestic properties are as energy efficient as possible.

"With a large number of older and heritage properties in the UK, there is a particular need to explore a range of options that will help people to keep warm and save energy while protecting the characteristics of these buildings," he said.

"This project not only enables us to learn more about installing the right solutions for heritage homes but provides us with a unique opportunity to develop research that will help underpin similar projects in the future."

(LM)