EN-04 · 02 Energy
Passive solar greenhouse
A glazed room aimed at winter sun, with mass inside and insulation behind, so plants and people take heat from the building instead of a burner.
Origin
High-latitude pit greenhouses and Chinese solar greenhouses
Materials
- A long axis running east–west, glazing to the winter sun
- An insulated north wall
- Water barrels or masonry as thermal mass
- Vents that can be opened by hand
Method
- 01
Site for winter sun, not summer convenience. A tree that shades the glass in January is a design error.
- 02
Put the mass where the light hits it — dark barrels, a masonry wall — so the room stores the day.
- 03
Insulate the north, east and west as if it were a house. A greenhouse that leaks heat is a cold frame with pretensions.
- 04
Vent at the ridge and the floor so heat can leave without a fan when the season turns.
- 05
Grow in the climate you actually built, not the climate on the seed packet. Shoulder-season greens will forgive more than tomatoes.
What this makes possible
- A growing season that starts earlier and ends later without a heater
- A room that can double as a workshop or washhouse in winter
- A pattern that scales from a lean-to to a community house
This is a field record, not a permit. Adapt to local law, climate and skill. If you have run this method, send what you learned.