Insulating wallpaper
Obviously the first step to a warmer home is to carry out cavity wall insulation, but if you've already done that and your house is still cold, or if you have an older property without cavities, there are products for lining internal walls that stop heat disappearing into the street.
It’s not a new concept; back in the '70s chilly walls were often covered with cork tiles stuck on with a foul-smelling black glue, or thin layers of polystyrene that indented every time you knocked against it. The good news is that today’s products are more sophisticated.
At the budget end you can still buy polystyrene products, such as Saarpor’s Heatsaver, a simple 2mm layer of polystyrene that needs to be covered with lining paper before decorating. Saarpor’s Red Label Insulating Lining Paper (£8.19 for a 10mx50cm roll) is slightly more sophisticated, consisting of a 4mm polystyrene layer laminated to a high quality non-woven lining paper, saving time on decorating. Saarpor also offers a Graphite Insulating Lining Paper (£12.90 for a 10mx50cm roll) which has the added bonus that the expanded polystyrene is infused with graphic particles, giving 20 per cent extra insulating performance with no extra thickness.
These wallcoverings require specialist adhesives to go with them, the cost of which can be significant (for example, Wallrock thermal liner paste costs around £20 for 10kg, enough to apply 10 rolls of 50cm wide paper).
Moving on from polystyrene, not an eco friendly product in itself, Wallrock (also called KlimaTec) wall lining products from Erfurt are a major step up. They're made from textile fibres and come on rolls of various thicknesses. KV600 comes in 15mx100cm rolls and is 4mm thick (£105 a roll), Thermal Liner is 10mx705cmx3.2mm (£40 a roll) and Cosy Liner KV300 is 10mx75cmx1mm (£34 a roll). Wallrock products can be painted or covered with paste-the-wall liners or wallpaper. You'll find them at various online retailers.
While all insulating products are green in the sense that they reduce energy usage, some are green in manufacture as well. Pavatherm Thermal Board, for example, is a rigid insulating board made from pulped wood offcuts that comes in six thicknesses from 20-100mm. Because it comes as solid boards rather than on a roll it is a harder job to fit, but it is modestly priced from just £3.89 for a 1020x600x20mm board. See mikewye.co.uk for more details.