Articles and insights.
Perspectives from the Aeterno team on building performance, the energy transition and decisions backed by evidence.
Your Home Is Not the Average Home
Almost everything you are told about your home's energy comes as a single number: a band, a running cost, a saving. We worked 107,336 homes through the national calculation method, and their modelled heating year runs from a few hundred hours to nearly six thousand. The average describes the middle of a wide curve, and your home is somewhere on it, not at the average.
The Heat a City Cannot See
We ran a scenario envelope over the 107,336 homes of Nottingham the public record lets us price: between pipework insulated as specified and pipework degraded to bare, a long external run would swing nearly ten percent of everything the city spends on space heating. None of it appears in any official figure, and a flat-hours assumption understates it for the median home by half.
The Average Crosses Once
We repriced one social housing estate under illustrative price futures to find out what the gas price would have to do to change its answer. Read as an average it has one threshold, and it sits beyond any plausible future. Read home by home it has 27.
One Spreadsheet Row, Two Decades Apart
Two social housing estates in the same English city, compiled from the public record and priced home by home. One already did most of the work. The other still burns gas in 310 of its 313 homes. A spreadsheet row cannot tell them apart.
Outcomes, Not Equipment
The sector's own guidance now tells social landlords to specify heat pump performance outcomes and verify them after install. The numbers behind that advice deserve a close read: seasonal performance is not a product property but a prediction, home by home, and delivery decides it.
The Homes Moved On. The Records Didn't.
Social housing plans its next decade of investment on energy records that predate a decade of works. Finding where each home truly stands, with provenance, changes what the plan says, and what it costs.
The Certificate and the City
One certified 8.5 kW air source heat pump, worked through 24,931 London homes for a full year, hour by hour. The median home delivers 3.6 against the certificate's headline 5.0, and the spread is decided by the homes.
The Commissioning Quality Gap
Public field data shows a wide spread in heat pump performance, and most of it is decided on the day the system goes in. What closes the gap is a record of what each install delivered, kept from its first hours.