DIYedBoy
You cannot say that Johns figures "are made up". They are accurate and work in a real sense in that a room may need a 1kW heater perminatley on to keep it at 21oC, and that insulation may then mean that only 500W of heating in a room is needed to keep it at say 21oC.
You can use the required heating in your house and the lamda value of materials to see what change is produced by use of insulation. Here are some landa values of materials, noting that it shows how much energy in Watts (W) it allows through a 1metre thickness (m) with a 1 Centegate (K) difference on each side of the thickness. If you want to model it You can then change the values by making the temp difference different from 1oC and the thickness different from 1m.
Material Approximate thermal conductivity (lambda-value) in W/(mK)
Natural stone ........................................ 3.500 W/(mK)
Concrete .............................................. 1.500 W/(mK)
Full brick ............................................... 0.760 W/(mK)
OSB (Oriented Standard Board).............. 0.130 W/(mK)
Wood (pine) .......................................... 0.140 W/(mK)
Clay blocks (e.g. Porotherm) ................. 0.160 W/(mK)
Aerated concrete (e.g. Ytong) ................ 0.130 W/(mK)
Mineral wool .......................................... 0.039 W/(mK)
EPS ....................................................... 0.036 W/(mK)
Here is a nice introduction to lamda, U and R values:
http://www.greenspec.co.uk/building-design/u-value-introduction/
and it shows that I feel is easier to model with U-values where using there example:
•The U-value of a single sheet of glass as found in a traditional window pane is 6.0W/m2K – which means that for every degree of temperature difference between the outside and the inside, a square metre of the glazing would lose 6 watts. So for example, if the temperature difference on a typical cold day was 15 degrees, then the amount of heat loss would be 15x6 = 90 watts per square metre. That’s a lot of heat!
• By comparison, the U-value of a modern piece of triple-glazing can be as low as 0.7W/m2K – which is not very much heat at all.
sfk