An interactive web-based tool that helps homeowners, designers, builders and housing associations work out the best refurbishment plans to cut carbon emissions in existing homes launches next month

Set up by The Association for the Conservation of Energy, the Building Research Establishment, English Heritage and 10 other partners, the T-Zero website aims to tackle the problems associated with the UK’s existing housing stock, acknowledged as a primary contributor to carbon emissions in the built environment.

The free tool takes users through a series of steps to determine key facts about the property concerned and works out its fuel bills and carbon footprint. Based on this information and SAP calculations, it will identify optimal insulation, heating, and renewable energy measures, based on the user’s budget and refurbishment goals.

‘The tool gives the homeowner or portfolio manager a way to sift options based on different criteria, for instance the EPC band, reducing carbon emissions, capital cost or pay-back period,’ says Jon Mussett, head of building design consulting at BRE.

‘Anyone can come up with measures, but how do you know that for another £500 you couldn’t do twice as well?’ he adds.

A test version of the web tool that allows calculations based on single properties is currently available. From May, a fuller version with more features will be available and further improvements will allow portfolio managers to calculate costs for multi-dwelling projects.

Registered users can save and download a recommended package report, and also access technical information. There is also a geographically-based database of suppliers and installers. Users can then link directly to the suppliers, manufacturers and installers of any options chosen, and request quotes through the site.