Solar Passive Greenhouse : Sitework checklist

• Sitework You aren't going to be providing water or electricity to your greenhouse - so that's moot. Excavate down to clay, about 18", stockpiling topsoil for later. If you have clay soil, some drainage is a really good idea. You'll be adding a very simple drainage system around the edge, and perimeter insulation.
  • Assuming the site is not perfectly level, make the excavation at least 18" deep on the high side.
  • The excavation size is the greenhouse footprint plus 2" on each side to allow for 2" of foam (pink) insulation.
  • Smooth the bottom of the excavation with a slight slope (at least 1:10) downhill (the same as the slope of the land) towards the lowest corner of the greenhouse.
  • Stockpile any extra clayey soil - not on top of the top soil!
  • At that lowest corner, add a drainage trench and I recommend doing it immediately so that the first rain comes, your excavation won't be full of water for a month.
  • Make the slope of the drainage ditch about 1:10, or if you do it as we did, in the rain, just keep digging until it drains.
  • Around the perimeter, dig down about another ~8" deep x ~10" wide.
  
  

Overview | Sitework | Drainage, Insulation, Flashing | Stone & Gravel | Foundation | Planting Beds
2 x 4 Walls