Lowtech Graph lists low-tech options for every need of a home. Here you can compare them, find tutorials to build them, and link them together into a circular system. Why low-tech?
Electrically heated table (kotatsu)
Needs the grid
One of 5 ways to meet this need. Cost, carbon, footprint and rankings are relative to other solutions for the same need, not absolute.
What your site needs
A table people already sit at, and a socket. Works in a rented flat, since nothing is fixed to the building
A low table with a heat source underneath and a thick blanket draped over it, as in the Japanese kotatsu. The blanket traps the warmth around the legs of whoever sits there. A little heat keeps people warm while the rest of the room can stay cool.
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
Electrically heated table (kotatsu) (This page) Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: Basic · Upkeep: Light · Change to daily life: Daily · Works without the grid: No Choose it if you want to keep everyone warm around one table while the room stays cool.
Hot water bottle Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: None · Upkeep: Light · Change to daily life: Daily · Works without the grid: Yes Choose it if you want the cheapest warmth there is, for one person, indoors or out.
Solar-powered foot stove (heat cube) Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Medium · Skill to build: Intermediate · Upkeep: Light · Change to daily life: Daily · Works without the grid: Yes Choose it if you want evening warmth from the day’s sun, with no fire.
Box-bed with thermal curtain Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: Intermediate · Upkeep: None · Change to daily life: Way of living · Works without the grid: Yes Choose it if you want to sleep warm, in the dark and quiet, in an unheated bedroom.
Insulating furniture (hooded chair, folding screen) Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: Basic · Upkeep: None · Change to daily life: Occasional · Works without the grid: Yes Choose it if you want to stay warm where you sit, sheltered from cold walls and draughts.
We don’t list sizing or quantities, as the yield of each technique depends on the quality of its build. The catalogue compares options but doesn’t dimension them. Regulatory notes are indicative, with a French example, and need to be confirmed locally.