Tag Archives: Polycarbonate

Greenhouse design, part 1

As I wrote in “Why”, I have my rough design idea. That idea must be developed into cost-effective design to reduce material waste, solve details and predict weak points in workflow.

I researched little about polycarbonate panels, that will be used for roof. Polycarbonate comes in different sizes and thickness. I choose 16 mm thick plates, because of insulation and load capacity (we can have a lot of snow). Width is 2100 mm and length is available in  4000, 6000 or 7000 mm.  To minimize polycarbonate waste, both sides of the roof must have total length of plate. I adjusted width of greenhouse to fit 6000 mm plates (see first screenshot, A+B=6000 mm)

Second, wood frame must be adjusted to fit 2100 mm plates. Greenhouse will have 10 cm cordon (overhang) around it. In assembly plan for polycarbonate (PC) plates is detail of 20 mm gap between plates, to fit sealing profile. So it also follows, distances between foundations will be 1.96 m, 2.12 m, 2.12 m and 1.96 m (see second screenshot).

Foundations will be simple. Drilled hole in ground will be filled with concrete and insterted profile for wood frame.


As food prices rise dramatically 1 and we can not be sure what additives, pesticides and conservators we get in supermarket vegetables and fruit, we decided to build greenhouse. I hope, it will give vegetables all year long despite the harsh winter conditions.

To illustrate our climate, we can have up to -25°C in winter and +37°C in summer. 2 We are located in small town next to Gornja Radgona, Slovenija.

Our first idea was geodesic greenhouse (biodome) made of wood frame, covered with lexan cell panels. I made some calculations for biodome 7 m diameter (38 m2) and it will cost around 4000€ to build it completely.  That’s was too much money to spend.

Next we found a greenhouse made in Slovenia, with nice characteristics and affordable price. Alpi 2/3. But we want more insulation than 4.5 or 6mm lexan panels, so we can grow food all year long.

So we came along “bolivian solar greenhouse”. It have steep south side to catch winter sun, insulated north side and large water tank to store heat during winter nights. All good features of geodesic greenhouse. What is the difference then? Price! It will cost around half. There won’t be almost any waste of costly lexan plates and there won’t be any problems with sealing roof windows, because i can use any standard window on sides.

There will be windows next to ground on south side and windows next to ceiling on north side + roof window. This will provide good air circulation during summer and prevent overheating. I also tend to install Misting Cooling System if needed.

1.12.2013: I did some modeling and winter sun simulation. Next step will be adjusting dimensions to reduce waste of building materials.

Read more here:  GREENHOUSE DESIGN, PART 1

All costs of building greenhouse.


  1. vegetables and fruit from 40% to 100% in one year ?
  2. Official source: ARSO ?