Section 04 of 04
What the model said, what the meter said
Every figure on this site is either a prediction or a measurement, and the two are not the same kind of thing. This section is about the distance between them, and about the plant that has to live with whatever the fabric turned out to be.
PLATE 1A meter and a modelled output on the same table — the two figures the performance gap is the distance between.
Start here
What the model said, what the meter said
The performance gap is documented across large samples, and the causes are mostly workmanship and modelling assumptions rather than any single failure.
Everything in this section
What the model said, what the meter said
The performance gap is documented across large samples, and the causes are mostly workmanship and modelling assumptions rather than any single failure.
Passivhaus is a number, not a look
The standard is a measured space-heating demand and an air-tightness limit, which is why it can be certified at all.
How cold the outside is, county by county
Degree days are how a heating demand is normalised, and without them two buildings cannot be compared.
The coefficient falls as the flow temperature rises
A heat pump's performance depends on what it is asked to heat to, which is why the emitters matter as much as the unit.
The other sections
Every guide, listed →
Section 04 of 04
What the model said, what the meter said
Every figure on this site is either a prediction or a measurement, and the two are not the same kind of thing. This section is about the distance between them, and about the plant that has to live with whatever the fabric turned out to be.
PLATE 1A meter and a modelled output on the same table — the two figures the performance gap is the distance between.
Start here
What the model said, what the meter said
The performance gap is documented across large samples, and the causes are mostly workmanship and modelling assumptions rather than any single failure.
Everything in this section
What the model said, what the meter said
The performance gap is documented across large samples, and the causes are mostly workmanship and modelling assumptions rather than any single failure.
Passivhaus is a number, not a look
The standard is a measured space-heating demand and an air-tightness limit, which is why it can be certified at all.
How cold the outside is, county by county
Degree days are how a heating demand is normalised, and without them two buildings cannot be compared.
The coefficient falls as the flow temperature rises
A heat pump's performance depends on what it is asked to heat to, which is why the emitters matter as much as the unit.
The other sections