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?

Haybox / retained-heat cooker (fireless cooker)

Passive

One of 11 ways to meet this need. Cost, carbon, footprint and rankings are relative to other solutions for the same need, not absolute.

A heavily insulated box that a pot is put into after being brought to the boil. The heat already in the pot keeps it simmering for hours with no more fuel, and the food finishes cooking on its own. It cuts the fuel for slow-cooked dishes by a fifth to four fifths.

Build it

Cost
Low
Upkeep
None
Skill to build
Basic
Lifespan
10-20+ years for a well-made insulated box; reflective foam liner may need earlier replacement than a hay-packed original
Embodied carbon
Low
Space / material use
Medium
Output timing
On-demand/controllable
Skill to repair
Basic

Inputs

Outputs

Compare the 11 ways to meet this need

Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.

Sources

Limitations of this page

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.