How to Save Energy
Airtightness and Ventilation
Airtightness
Basic draught proofing and low-cost ventilation is in our Low and No-Cost Measures section. When considering a deeper retrofit project, an airtightness strategy is necessary. This involves incorporating an airtightness layer around the entirety of the home - a way to imagine this is having a bucket with no holes placed inside a leaky bucket with holes. A mixture of detailed design and the use of advanced membranes, sealants and insulation is used to help achieve a desired air tightness level.
Ventilation
When the insulation and airtightness of a building is improved, it is important to make sure that adequate ventilation is maintained – the more airtight a building is, the less natural ventilation it receives. It is important to note that just because a house is airtight does not mean it isn’t ventilated – either by natural means such as windows and trickle vents, or mechanically by extraction ventilation or Mechanical Ventilation with Heat Recovery (MVHR).
MVHR is a whole-house system that extracts stale air from rooms in your house and supplies fresh air. When warm, stale air is extracted from your home through MVHR, the system recovers around 80-90% of the heat to pre-warm the fresh air being supplied back into your home. Air is typically extracted from warm and wet rooms in the house (kitchens, bathrooms) and supplied into bedrooms and living spaces. MVHR systems are commonly found in new-build homes and whole-house retrofits which reach high thermal performance and airtightness standards.
A whole-house MVHR system is not cheap and can be complex. It requires air ducting to be installed throughout the house and this can be an intrusive process therefore combining this with other more significant retrofit works is advisable.
You can find out more about airtightness and ventilation on the Centre for Sustainable Energy's website.
Kingston Retrofit Guidance for Households
To read more information about all these measures, Kingston Council has developed a Retrofit Guidance for Households to provide information on energy efficiency improvements which can help to reduce energy bills.