Your house
Heat loss, the flow temperature it can reach today, the flow temperature after the work we would quote, and how many radiators change. These are our own averages from 412 surveys.
Heat loss
9.5 kW
Demand
16.5 MWh
Flow, as is
55 °C
Flow, after
45 °C
The hardest common case in Britain. Without insulating the solid walls you are paying to heat the street, and we will say so before we quote — even though the quote is bigger if we do not.
Radiators typically changed: About 70%
Heat loss
8.2 kW
Demand
13.8 MWh
Flow, as is
50 °C
Flow, after
40 °C
Fill the cavity first. It costs a fraction of the heat pump, it takes a day, and it moves this house down a whole flow-temperature step — which is worth more than any brand of heat pump.
Radiators typically changed: About 50%
Heat loss
8.8 kW
Demand
15.2 MWh
Flow, as is
50 °C
Flow, after
40 °C
Usually a straightforward job. Top the loft up to 300mm while the scaffolding logic is fresh in your mind; it is the cheapest kilowatt you will ever buy.
Radiators typically changed: About 40%
Heat loss
6.4 kW
Demand
10.4 MWh
Flow, as is
45 °C
Flow, after
40 °C
Often runs at 45 °C on the existing radiators, which means a cheaper install and a lower bill than the neighbours expect.
Radiators typically changed: About 25%
Heat loss
3.4 kW
Demand
5.6 MWh
Flow, as is
40 °C
Flow, after
35 °C
The easy case, and the one where the numbers genuinely beat gas from day one — provided there is somewhere outside to put the unit, which in a flat is the real question.
Radiators typically changed: None, usually