Energy Saving Case Study 16
View more Case Studies in your area...
House Age: Post War (1940 - 1970)
Energy Saving Improvement 1
Type: Solid Wall Insulation
Contractor: Homeworks Energy
Description: 100mm urethane foam boards fixed to the existing stone clad external wall surface and finished with an acrylic render
Cost: £0 (value £10,000 in 2013)
Energy Saving Improvement 2
Description: Worcester Bosch Greenstar 25 CDi gas fired combination boiler
Cost: £2,000 (2010)
Energy Saving Improvement 3
Type: Loft Insulation
Description: Loft insulation topped up to 200mm with glass fibre quilt
Energy Saving Improvements Details
This is was a 4 bedroom semi-detached house dating from the 1950s although the smallest bedroom has now been converted into an en-suite bathroom. It was built by the local council for social housing but is now owned by the householder. It is a “System” built property with “no-fines” concrete walls, solid floors and a pitched roof and is located near the heart of a small village and it also has a mains gas supply.
In its original condition the house would have scored SAP39 in EPC band E and is estimated to have required 407kWh/m2 of gas for heating and hot water, producing 7.1 tonnes CO2.and costing £1,453 per year.
The loft insulation was increased a few years ago so that it now reaches 200mm thickness and this would have resulted in a reduction in the heating load of 16.9% and saving 1.2 tonnes CO2.
Previously the householder had carried out a number of improvements including replacing the windows with double glazing and more recently, renewed the boiler with a condensing combination boiler. These saved a further 1.8 tCO2 bringing the total saving from energy efficiency measures to 42.3%.
The property was included in a pilot scheme in 2013 run by the County Council and was amongst a number of homes fitted with external wall insulation at the same time. This further reduced the energy requirement to 152kWh/m2 and carbon emissions to 2.6tCO2. In total, a 63.4% improvement has been achieved from the assumed original condition.
This indicates that even a difficult to heat home can achieve significant savings with a number of appropriate improvement measures. The house now achieves an energy efficiency rating of SAP74 in band C with a combined heating and hot water energy cost estimated to be no more than £550 each year. The annual environmental impact of the property has reduced from 5.4 to 2.2 tonnes CO2.
On a more personal note, the householder is now much more comfortable in the winter with the extra insulation keeping the heat in, but has also noticed the cooling effect during the recent heat wave by keeping much of the unwanted heat out.