To discuss your project give us a call on 01392 861763

What is energy efficiency and why is heat recovery ventilation important?

Find out more about our approach to this building scenario.

Energy efficiency of appliances within sustainable homes is very important as they are a significant source of heat as insulation levels increase. This may seem unimportant during the winter months as they are an extra source of heating, reducing the load on your heating system. However, during the warmer months of the year they can contribute to an overheating risk and consume unnecessary energy.

Heat recovery ventilation is a very important part of low energy sustainable construction. It allows the continuous supply of fresh air without losing the heat from the air that is extracted from bathrooms and kitchens. In the middle of winter some systems return 10 kWh of heat in the incoming air for every 1 kWh that used to run the fans, efficiencies that heat pumps can only dream of!!

In a ‘conventionally’ ventilated home the ventilation comes from drafts, open windows, trickle vents and extractor fans. These methods are occasionally effective at providing the required amount of fresh air but they do not recover any of the heat lost from the outgoing air. This means that just to heat up the incoming fresh air your heating system may be supplying several kilowatts of heat, before accounting for the heat lost through the doors and windows, walls and roof.


If you want to find out more about how to effectively manage your sustainable building project, check out The Self-Build Series. This series of guides has been put together to you understand sustainable construction. We hope you find them useful!

CPD Training

We offer CPD training for architects practices across Devon and Cornwall.

Software Modelling

We offer dynamic heat and moisture modelling as well as condensation risk analyses.

Building Plan Review

If you have some plans and would like our opinion on which materials would be the best for you, contact us.


Back to Earth is a natural building material supplier. We're not your typical builders'​ merchant though and instead work closely with our clients during the planning, designing and building phases of projects.

Back to Earth is a proud signatory of the Anti-Greenwash Charter:

© 2023 Back to Earth