Ask for the u-value of the insulation or glazing. This is the speed of heat loss through the surface – and the lower the number the better. U-values to aim for are: lofts 0.15, walls 0.35, oors 0.2, double glazing 1.6, secondary glazing 2.6.
The use of natural materials such as sheep wool loft insulation, lime plaster and render, hemp, cork and wood bre boards is usually recommended for old buildings because they allow moisture to escape, which avoids problems with damp, mould and condensation.
Radiator reflectors are panels fitted behind the radiator that reflect heat into room, saving around
7% of heating fuel. Radiator-enhancing fluid makes the heating system more efficient. Adding a litre
of this fluid to the heating system and can reduce energy use by 15%