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?
Insulated slab edge and slab-to-wall thermal break
Passive · New build only
One of 4 ways to meet this need. Cost, carbon, footprint and rankings are relative to other solutions for the same need, not absolute.
Insulation laid around the edge of the floor slab and under its outer strip when the house is built, with a break between the slab and the foundation wall. Heat can no longer leak from the floor into the cold ground at the edges. Floors stay warmer and the house loses less heat.
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
Insulated slab edge and slab-to-wall thermal break (This page) Can I use it? Not in a flat · New build only What does it cost me? Upfront cost: Low · Skill to build: Intermediate · Upkeep: None · Change to daily life: None · Works without the grid: Yes Choose it if you are pouring a new slab and want warm floors at the edges from the start.
Continuous exterior insulation detailing Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Medium · Skill to build: Basic · Upkeep: None · Change to daily life: None · Works without the grid: Yes Choose it if you want every beam and post covered, leaving no cold spot anywhere on the house.
Strapped straw external insulation (ITE paille sanglee) 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 want to wrap an old house in thick insulation cheaply, without touching the rooms.
Exterior slab-edge insulation (retrofit) Can I use it? Not in a flat · No rebuilding needed What does it cost me? Upfront cost: Medium · Skill to build: Intermediate · Upkeep: Light · Change to daily life: None · Works without the grid: Yes Choose it if your house already stands on a slab and you want its cold floor edges put right.
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.