Calculations
The concern about the heat pump is the running costs. Even though the efficiency is 1 to 4 (1kWh in gives 4kWh out), the economics & CO2 savings are somewhat different.
My last bill including VAT

1 unit of electricity = 14.58p
1 unity of Gas = 5.17p (see note about split costs below)
No. kWh of Gas used [...]

Given the current plans what additional insulation is required to reduce the amount of heat that is generated by the heat pump ?
Assuming additional insulation is applied, how much electricity will be used to power the heat pump ?

This information is an input to the PV requirement

Is it possible that heat from the Solar heating [...]