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?
South-facing attached sunspace / solar greenhouse
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.
What your site needs
A genuine south-facing aspect and space for an attached structure
A glazed room built against the south wall of the house, like a small greenhouse. The sun warms the air and the floor inside it, and that warmth passes into the house or is let in through doors and vents. It can cover a large part of the heating and gives a bright extra room.
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
South-facing attached sunspace / solar greenhouse (This page) 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: Occasional · Works without the grid: Yes Choose it if you want free winter heat and a bright extra room on the south side.
North-facing unheated utility buffer room Can I use it? Not in a flat · New build only What does it cost me? Upfront cost: Medium · Skill to build: None · Upkeep: None · Change to daily life: None · Works without the grid: Yes Choose it if you are planning a new house and want its cold side shielded by rooms you do not heat.
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.