Yeah no. It's become a bit of a hobby of mine, heatpumps. If I ask 5 experts/installers to take a look at a building I'll get 6 estimates, varying wildly. Plus,

Yeah no. It's become a bit of a hobby of mine, heatpumps. If I ask 5 experts/installers to take a look at a building I'll get 6 estimates, varying wildly. Plus, installers are still consistently over dimensioning and thus killing your sCOP, because they don't want customers to complain 'its slow to heat' and so on. Calculating the heat loss of a house is really not trivial. Often you'll have no idea of the materials used or the quality of installation, and not really a way of finding out unless your up for some destructive investigation.