Needs power
Burns gas to heat water for radiators or underfloor circuits, recovering some of the heat that would otherwise leave with the flue gases. The conventional answer to house heating in France, and the thing most of the passive options here are implicitly compared against.
One of 4 ways to meet Active backup heating. Build 3/4, Upkeep 2/4, Efficiency not rated. Cost, carbon and footprint below are rated against those 4, not in absolute terms.
A gas supply or room for a tank, and a compliant flue route
Every option in this sub-function, with the value on each axis and a note on what drives it (this solution highlighted):
| Solution | Build skill | Upkeep burden | Efficiency |
|---|---|---|---|
| Wood stove / mass heater | Basic | 5 | #3 |
| Heat pump (air- or ground-source) | Specialist | 8 | #1 |
| Rocket mass heater | Intermediate | 5 | #2 |
| Gas boiler (condensing) | Specialist | 6 | N/A |
Build skill and upkeep burden are proxies (lower burden = simpler to maintain); the efficiency column is this sub-function’s ranking, 1 = best. “N/A” where an axis isn’t rated here.
No sources recorded yet.
No build tutorial recorded yet.
No sizing or quantities: how much a technique yields, and how much a household needs, both depend on the build and the people, so the catalogue compares options rather than dimensioning them. It carries no bill of materials and no build sequence, and it is written for an oceanic, clay-soil climate (Normandy, France). Regulatory notes are indicative and need confirming locally.