| Value | Category |
|---|---|
| 1 | Shared central heating (shared by all most of the dwellings in the building including urban heating) |
| 2 | Individual central heating with a stove in the dwelling |
| 3 | All electric heating with a stove in the dwelling |
| 4 | Other means of heating (pan, chimney, stove, movable radiators, water heaters, etc.) |
| 9 | NIU (not in universe) |