Typically, an existing home gives off more than double the carbon emissions (and has twice the fuel costs) of a new house.
Retrofitting existing housing gives better energy and carbon savings per pound spent than any new build measure or renewable technology. Key energy saving retrofit measures to consider are controlling ventilation by draught proofing, blocking up unused chimneys, sealing leaky timber ground floors and introducing humidity controlled extractor fans where needed;
Insulating solid walls, replacing single glazed windows with new high performance double glazed windows, filling cavity walls, and insulating lofts and roofs; installing new highly efficient gas condensing boilers with thermostats and programmers and thermostatic radiator valves.
But this is just the technology. A good retrofit will look at much more than the physical changes to an individual house.
1. Think about the wider effects of each measure
Retrofitting measures, as above, should be considered as a package. That will mean maximum energy savings but will also avoid adverse effects such as increasing dampness and mould by excessively reducing ventilation or creating cold bridges (areas that are especially cold, as partial insulation of some areas can result in others becoming colder than before).
2. Look at the bigger picture
Experience suggests that the greatest efficiencies can be made by taking a wider approach to refurbishment. Those embarking on a refurbishment scheme should focus on the desired overall outcome. Some of the worst housing in energy terms is also occupied by the poorest people, both low income renters and homeowners.
Carbon reduction is king at the moment, but it is also worth considering how the retrofit might affect factors such as individual and community well-being, water use, climate change adaptation and food provision.
3. Consider an area-wide strategy
Looking at the business case for carrying out retrofit schemes on a large scale. Early...