How much do heat pumps consume in the winter months compared with summer months, e.g. for hot water, showers, baths, washing, etc.?
How long does it take for a heat pump to warm up a cold home? e.g. you leave the heating off during the day and it comes on 30 mins before you arrive home.
Comparing running costs, which is more expensive: heat pumps or gas/oil boilers?
How many "homes" can have a ground source heat pump installed? Obviously it's fine if you've a large field and lake, but not when you've an average sized garden -- which is nobody with a Barratt home which has a back yard, nor a flat. Is that 10% of homes can have ground source heat pumps? 5%?
What's the efficiency of an air sourced heat pump in comparison with a gas/oil boiler? Running costs again.
As I said above, the sums don't add up. The installation costs are ridiculously high for heat pumps -- the cost of many years of running costs for oil/gas boilers.
The running costs don't make financial sense either. Maybe 40 years in the future, but that is not now. Worse still, you're committed to buying electricity at the point of use at some unknown pricing. Oil can be bought any time during a year, there's seasonal fluctuations in price.