Insulating a Wall: What You Need to Know

insulating a wall with cavity rigid board in extension project
(Image credit: Ian Rock)

Insulating a wall, either internally, externally or in a cavity, is an important part of achieving thermally efficient home. Not only is a more efficient home better for the environment but a home where heat loss is kept to a minimum means lower energy bills and increased long-term savings. 

The amount of heat a building loses is measured in a couple of ways, including a home's EPC rating where homes are placed into bands A-G, with the A including the most efficient houses. Although the average home is band D, a survey by the PWC Economic Outlook in 2021 suggested that 1/4 of energy bills could be saved (approximately £178) is households upgraded their homes to EPC rating band C.

Tim Pullen

Tim is an expert in sustainable building methods and energy efficiency in residential homes and writes on the subject for magazines and national newspapers. He is the author of The Sustainable Building Bible, Simply Sustainable Homes and Anaerobic Digestion - Making Biogas - Making Energy: The Earthscan Expert Guide.

His interest in renewable energy and sustainability was first inspired by visits to the Royal Festival Hall heat pump and the Edmonton heat-from-waste projects. In 1979

this initial burst of enthusiasm lead to him trying (and failing) to build a biogas digester to convert pig manure into fuel, at a Kent oast-house, his first conversion project.

Moving in 2002 to a small-holding in South Wales, providing as it did access to a wider range of natural resources, fanned his enthusiasm for sustainability. He went on to install renewable technology at the property, including biomass boiler and wind turbine.

He formally ran energy efficiency consultancy WeatherWorks and was a speaker and expert at the Homebuilding & Renovating Shows across the country.