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?
Stack-effect / solar chimney ventilation
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 design allowing a real vertical stack height and low-to-high opening separation
A tall shaft or chimney that is warmed at the top, often by the sun. Warm air rises and escapes out of the top, pulling fresh air in through low openings to replace it. It ventilates and cools the house with no fan, even on a day without wind.
Levels are relative to the other options for this need, not absolute. Fewer dots is lighter.
Stack-effect / solar chimney ventilation (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: Occasional · Works without the grid: Yes Choose it if you want ventilation with no fan, even on still days.
Cross-ventilation (opposed openings) Can I use it? Works in a flat · No rebuilding needed What does it cost me? Upfront cost: Low · Skill to build: None · Upkeep: None · Change to daily life: Occasional · Works without the grid: Yes Choose it if the wind can reach windows on opposite sides and you want free ventilation.
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.