Plan your home energy improvements
Free calculators built on official UK data. See costs, savings, grants, and payback periods for heat pumps, insulation, solar panels, and more.
Heat Pump Cost Calculator
Installed cost, the Boiler Upgrade Scheme grant (£7,500, or £9,000 for oil or LPG homes off the gas grid), running costs against your current heating, and your payback.
Most popular
Heat Pump Running Costs
What a heat pump would cost to run in your home each year, on a standard or heat pump tariff, against your current heating.
Standard and heat pump tariffs
Insulation Savings Calculator
See how much you could save with loft, cavity wall, or solid wall insulation. Check if you qualify for free installation.
Free insulation available
EPC Improvement Planner
Find the cheapest way to improve your EPC rating. Improvements ranked by cost-effectiveness. Essential for landlords.
Landlord essential
Landlord EPC Calculator
Check a rented home against the rules, including band C by 2030, and the cheapest upgrades to get there within the spending cap.
For landlords
Solar Panel Cost Calculator
Calculate generation, bill savings, Smart Export Guarantee income, and 25-year returns based on your roof and location.
0% VAT until 2027
Boiler vs Heat Pump
Full 15-year cost comparison of a new gas boiler against a heat pump. Installation, running costs, maintenance, and grants.
Side-by-side comparison
Grant Eligibility Checker
Check your eligibility for the Boiler Upgrade Scheme, ECO4, Warm Homes grants and other UK energy grants in one place.
Up to £9,000 for a heat pump
Energy Bill Calculator
What a home like yours should pay for gas and electricity at the October 2026 price cap, and whether your own bill is high.
Typical 3 bed semi: £1,885 a yearNew this autumn
Home Buyer Energy Check
Buying a home? Enter its EPC band for the energy bill, the cheapest upgrades to band C and the payback.
For home buyersNew Boiler Cost Calculator
What a new boiler costs to fit in your home, what it saves on gas, and how a heat pump compares.
Combi, system or regularBoiler: Repair or Replace?
Got a repair quote? See it against the cost of a new boiler and what a new one would save each year.
Check a repair quoteEV Cost Calculator
Electric against petrol or diesel: charging, fuel, road tax and the pay-per-mile tax from 2028.
Includes the 2028 taxBuilt on official UK data
Ofgem energy prices
Updated with each new price cap. Currently using Ofgem rates for October to December 2026.
Measured savings
Insulation savings measured in thousands of real homes by the government, with Energy Saving Trust installation costs.
DESNZ data
Government energy consumption data for 39,502 gas heated homes, published under the Open Government Licence.
GOV.UK grants
Grant schemes checked against published eligibility rules, last reviewed in September 2026.
Public data, with dates
Every figure comes from government, regulator or Energy Saving Trust data, with the date we last checked it. See our data.