Greenhouse Plans

We are now selling our 30 page plans for our 12′ by 21′ four-season greenhouse, including:

  • structural drawings,
  • earth-air heat exchanger design,
  • automation system design (optional),
  • aquaponic system design (optional),
  • a list of materials and recommended suppliers.

This greenhouse is designed to provide the conditions to grow food year-round in New Brunswick without needing supplemental heat. This greenhouse has been designed to capture, retain, and store solar energy through its glazing, insulation, and EAHE respectively.

Polycarbonate glazing is used to have a high R-value while also keeping light transmittance as high as possible.

R-33.7 walls keep the heat in and the cold out, and an optional interior insulating blind can be added to increase the overall effective insulation level by the building by nearly 30% overnight!

The earth-air heat exchanger uses a fan to store extra daytime heat underground so that it can be accessed through the night, and even stores summer heat for use in the winter. Although an exhaust fan is included in the design to help cool the greenhouse in the summer, high and low vents have been designed into the greenhouse to allow for passive ventilation.

In New Brunswick, accessory structures such as greenhouses that are less than 56.08 square meters do not require an inspection by the province, but do require a building permit. Your Regional Service Commission can provide you with the building permit application form and the cost is about $50. This design package includes a sample building permit application with the required structural and insulation information already filled in.

For those requiring engineered drawings to obtain a building permit, these plans have been approved and stamped by an engineer. That being said, as snow loads vary across the province, this current design has only been approved by the engineer for the Fredericton and Miramichi areas. For residential areas, engineered drawings should not be required to obtain a building permit, and this design can therefore be used outside of these specific regions.

If you are interested in building this four-season greenhouse or have any questions, contact us at The plans are available for $500 CAD + tax as a PDF.