The GreenPhab is the Sophab Arch grown into a greenhouse — a curved, glazed shell that banks solar heat by day and holds it through the night, so your garden keeps producing even through a Canadian winter.
The same solar-passive geometry that heats a home works just as well for plants. The arch catches low winter sun and floods the beds with light, while thermal mass inside soaks up the day's heat and releases it overnight — flattening out the cold snaps that end an ordinary growing season.
Start seedlings early, push the harvest late, and keep hardy crops going straight through winter on captured solar heat.
Thermal mass and the glazed buffer smooth out day-to-night swings, so plants aren't shocked by frost or midday scorch.
The sun does most of the heating. Add earth tubes and you can hold frost-free temperatures with almost no active energy at all.
Locally fabricated timber ribs bent to the arch and skinned in clear polycarbonate — the same shell as every Sophab, engineered for snow and wind, sized to your yard and how much you want to grow.
Inside, thermal mass — water drums or a masonry back wall — banks the day's heat, and vents keep summer from overheating. It can lean against a south wall or stand free in the garden.
Buried pipe uses the ground's steady temperature to pre-warm the greenhouse in winter and pre-cool it in summer. Paired with the GreenPhab, it's the closest thing to a self-tempering, year-round garden you can build.
