Building the greenhouse took two of us just under two days and was relatively easy. 
The first picture shows the rear and side frames built and the trench for the electric cable can also be seen. The gravel has the weed control underlaid.
One very useful tip for this particular set-up, not stated by manufacturers, is to invest in a durable and weatherproof rubber strip that can sit under the frame base, all the way round. In this case it helps hold the ends of the fabric in place, but its real benefits are:
- It helps compensate for any unevenness in the base, though that needs to be as level as possible to begin with and is best accomplished by checking diagonally across the flagstones rather than simply lengthways around the edges.
- The greenhouse frame, with the glass in place, will bed into the rubber and there is some tolerance in the rubber to allow this to happen.
- It makes the frame exceptionally sturdy and stable.
Manufacturer’s instructions err on the side of caution, for understandable reasons. With experience, you know which instructions are more important than others. It didn’t apply in this case, but the general rule should be “if not sure, then follow the instructions”.
There will be a vast range of scenarios based on greenhouse type and purpose, location and many other variables. The key is to plan and think it through.
Greenhouse ventilation is one of the most important aspects, and the second picture, shows the finished greenhouse structure with an optimum placement of roof vents diagonally opposed and louvres placed low in the sides on the other diagonal.
This is the easy part, the real challenges await!