Methodology
How the 3d house tour works
Watt’s House uses the same house and twenty topics, with Watt the cat as guide.
A 3D cutaway of a 1930s semi that runs entirely on electricity, with a short explanation of twenty things in it.
How it works
The house is an illustration, not a design: a typical 1930s semi with a heat pump, hot water cylinder, radiators, solar panels, a battery, a car charger and an induction hob.
Costs, savings, performance and noise are given as typical ranges. Each topic lists its sources, with the date they were checked, under “Sources”. A text-only version lists everything and works on any device.
Most sources are gov.uk, Ofgem, the Energy Saving Trust, MCS, DESNZ statistics and the Electrification of Heat trial.
Figures used
All figures
Listed under each topic
Inside the tour, with their sources · Checked 14 August 2026
Limits
- Typical ranges aren’t quotes. Costs and savings depend on the house, the tariff and how it is used.
- This is one example house. Yours will differ in size, age and layout.
Last reviewed 1 October 2026. Next review due by 1 April 2027. Try the 3d house tour.