Last fall we built this lean-to greenhouse in order to extend our growing season, which is limited by frost and cold starting in the fall and extending through late spring. When taking this photograph, the greenhouse thermometer showed 75 degrees F., versus 23 outside, with a windchill at 11.
Like many people, we have a limited budget so we aimed to complete this project without spending much. The total cost amounted to much less than even an inexpensive kit greenhouse. We limited our purchases of new materials for this project by re-using six sliding glass door panels that came from our house.
Like most things made by people, double-paned glass doors have a limited lifespan as well as a limited warranty. Their seals usually become ineffective after several years, at which point their insulative qualities greatly diminish. We found this to be the case with a half-dozen doors in our house and we saved them for this project when we replaced them.
As is evident in the photo, the broken seals cause moisture to appear within the glass panes. In the case of the greenhouse, this serves to limit direct sunlight, which can harm small plants, but still capture the heat of the sun to maintain its warmth. Thus, what's detrimental in our house works beneficially in a different context: there is nothing good nor bad, but thinking makes it so. An unacceptable limit in one situation is actually a benefit in another.
This greenhouse serves not only as a place to start young plants for transfer to our garden, but also keeps our chickens warm. We built it against the wall of our coop, where it serves well to limit direct exposure to external cold wind and air while at the same time providing warm air to keep the chickens comfortable. Soon we will install an automatic heat-activated device that will open a vent at the top of the greenhouse, in order to limit the heat build-up during warmer weather.
Also, in the very near future, we will install some wire shelving along the main glass wall and begin planting seeds. We also expect to have an early crop of lettuce and other vegetables completely grown inside, not limited by the cold and snow still evident outside.
Nikon D70 with Nikkor 10.5mm lens on a tripod with a Nodal Ninja head; PTGui Pro, Photoshop, Pano2VR.