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?
Airtight membrane with taped/sealed joints
Passive
One of 2 ways to meet this need. Cost, carbon, footprint and rankings are relative to other solutions for the same need, not absolute.
A continuous membrane on the warm side of the insulation, with every joint and opening taped shut. It stops warm indoor air leaking out through gaps, which is where much of a house’s heat is lost. It only works alongside a planned way of bringing in fresh air.
Membrane itself: 30-50+ years if undisturbed and UV-protected; taped seams are the actual weak point and should be checked at any later penetration/renovation
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
Airtight membrane with taped/sealed joints (This page) Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: Intermediate · Upkeep: Light · Change to daily life: None · Works without the grid: Yes Choose it if you are building or stripping walls and want to stop the air leaks where much of the heat escapes.
Draught-proofing an existing house 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: None · Works without the grid: Yes Choose it if you live in an existing house and want the cheapest first step, an afternoon at a time.
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.