Get More Heat Hours For Your Money
WattsWatt is a public health service designed to help every household stay warm during winter by making your energy spend stretch further. In fact, we are on a mission to pump up to £4 billion more heat hours into Britain’s homes this winter, and every winter, to protect properties from damp and mould, and to protect the NHS from avoidable winter spikes.
WattsWatt was co-founded by public-health expert Lisa Malyon and is the UK’s first National Energy Service.
WattsWatt is a social-enterprise, meaning we exist to help society. We do this by guaranteeing that no household will ever overpay for energy again. Using smart-meter data, tariff transparency, and behavioural insights, WattsWatt helps families convert money into warmth more efficiently while tackling the health and financial toll of cold, damp housing.
"Out of 28 million households in the UK, 17.9 million households are on a standard variable tariff, which means they are overpaying by 5%-14% compared to the best value fixed tariff.
When you consider that 6.3 million households are classified as being fuel poor - if we made sure they were on the right tariff, we could pull many of these households out of fuel poverty."
Costing health and damaging housing stock
Collectively, these 17.9 million households are overpaying between £1.4 billion and £3.9 billion a year under the false protection of the price cap - almost equal to the £1.4 billion the NHS spends annually treating illnesses caused by poor indoor air quality. Both stem from the same national failure: cold, inefficient homes that cost lives as well as money.
Are you rationing heat?
Households affected by heat rationing may wish to visit our partner projects working to protect public health: Indoor Air Aware / Mums Versus Mould / UK Centre for Mould Safety / Fairer Warmth.
About our totaliser
Our Unlocked Heat Hours Totaliser shows how many more hours of warmth we've helped households access since launching WattsWatt.
Every time someone uses WattsWatt to find a cheaper tariff, we calculate how many extra hours of heating that household can afford compared with staying on a price cap tariff (standard variable).
Cheaper energy unit rate = more affordable warmth = more heat hours unlocked.
Why heat hours?
Pounds saved are abstract. Warm hours in a heated room are human.
‘Heat hours’ are a tangible benefit in enabling a #BetterBritain - and that’s our mission. At WattsWatt, we get excited to know every interaction with our service can unlock important heat hours for households, meaning their home stays warmer, for longer, which improves comfort and health outcomes.
We think of heat hours as a social currency and we will do everything in our power to keep unlocking them for a #BetterBritain. We want to see kids able to find a warm quiet room to do their homework, the elderly to ditch the electric blanket and heat the room, and every home warm enough to avoid mould and damp.
Why don’t we ever use the term ‘save’ or savings’?
Traditional price comparison sites talk about savings, but that’s guesswork.
They don’t know how much energy you’ll use. You might use more and spend more.
WattsWatt does something more honest. We show the extra warmth you can afford, not an estimated annual bill reduction.
Behind the maths (for the curious minds)
We have modelled home heating based on annual heat demand per square metre, applied to a typical room size.
Example:
A 17m² living room needs around 1610 kWh/year to heat.
We divide that across:
- 135 heating-season days (31 Oct – 15 Mar)
- 12 hours/day expected heating
Then apply energy efficiency assumptions:
- Gas central heating boiler 85% efficient
- Electric heating 100% efficient
- 60% of annual electricity consumption is for space heating (https://www.parliament.uk/documents/post/postpn249.pdf)
- 77% of annual gas consumption is used for space heating (BEAMA UK-homes-Analysis-of-kWH-gas-consumption-for-heating.pdf)
Become a Heat Hour Hero
Support your community by helping households unlock warmth.
You can register as a WattsWatt Ambassador and help neighbours - especially those who aren’t digitally confident - access more heat hours and stay warm this winter and every winter.
Warm homes are a human right. Join us.