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A live view · for housing and place

Where does a city's invisible heat go?

Nottingham: every home our stock model can price from public records, 107,336 of them, simulated through a full year, hour by hour. Choose a pipe run and an insulation state below, and the whole city answers at once: what that scenario sheds in a year, which wards carry it, and how far the real heating hours sit from the number the textbook assumes. Nothing here runs on your device; every figure is a verified, published record.

The story of these numbers: The heat a city cannot see.

107,336 homes1,195 GWh of space heat a yearmedian heating year 3,592 hours

If every run in the city were 5 metres of bare copper, the pipe alone would shed

71.2 GWh a year

6.0% of everything the cohort spends on space heat · median home 628 kWh a year

The formula is linear in length: about 14.2 GWh a year per metre of bare run, city wide.

Where it concentrates, ward by ward

1.64.6 GWh

Hover, tap or tab across the map to read a ward. Click to pin it while you change the scenario.

Twenty wards, 106,785 homes between them, every figure an aggregate of at least ten homes; the remaining 551 homes appear only in the city total. The shading is the selected scenario's annual loss per ward.

At 5 metres, the distance between bare copper and 25 mm phenolic is 59.7 GWh a year across the city, 5.0% of everything its homes spend on space heat. That is the part of the scenario that insulation, fitted once, holds back every year after.

The hours behind every cell

A pipe sheds heat while the heating runs, so the loss follows the hours. The textbook season is 1,800 hours; the city's median home heats for 3,592.

0 to 750 hours: 10 homes750 to 1,000 hours: 39 homes1,000 to 1,250 hours: 273 homes1,250 to 1,500 hours: 745 homes1,500 to 1,750 hours: 1,316 homes1,750 to 2,000 hours: 1,838 homes2,000 to 2,250 hours: 3,207 homes2,250 to 2,500 hours: 3,810 homes2,500 to 2,750 hours: 4,382 homes2,750 to 3,000 hours: 7,428 homes3,000 to 3,250 hours: 12,335 homes3,250 to 3,500 hours: 13,393 homes3,500 to 3,750 hours: 10,713 homes3,750 to 4,000 hours: 4,724 homes4,000 to 4,250 hours: 3,109 homes4,250 to 4,500 hours: 3,399 homes4,500 to 4,750 hours: 5,549 homes4,750 to 5,000 hours: 13,982 homes5,000 to 5,250 hours: 8,262 homes5,250 to 5,500 hours: 8,188 homes5,500 to 9,000 hours: 634 homes1,0002,0003,0004,0005,0006,0001,800 h assumed3,592 h median

Bar area is proportional to homes; wider bars are small groups merged to keep every group at ten homes or more. One home in ten heats for fewer than 2,474 hours; one in ten for more than 5,175.

What this view shows, and what it does not

  1. It shows a stated scenario priced over the cohort's real simulated heating hours, never a claim about any particular home's pipe.
  2. It shows aggregates only. The smallest group on this page is ten homes; no address, identifier or figure for a single home is published.
  3. The formula and its constants are stated in full below. The records for individual homes behind the aggregates stay in the governed record, where readings for a named place can be requested.

Ask this about your place

Nottingham is one city, compiled from records that are already public. The same cohort can be built for any city, borough or patch in England, and the same questions asked of it. Name yours and we will return the first cut: the homes, the hours, and what the scenario says at ward level.

Needs your name, email, organisation and a patch.

We send exactly what you enter here: name, email, organisation, patch. It is used only to compile the first cut and reply (usually within a few days). Indicative figures from public records; no data is needed from you to start.