ᐅ Garden shed / greenhouse made from extruded polystyrene foam (XPS)

Hi,

I saw a house built entirely from XPS/Styrodur insulation here in the forum. However, the related questions from the original poster were not answered, so I need to follow up and adjust my question to fit my project...

I’m planning a "greenhouse," or let's call it a tortoise shelter, in my garden. It needs to be very simple, lightweight, but weather-resistant... So here’s my question:

Is it possible to build walls from 100mm (4 inches) XPS/Styrodur? The longest wall would be 3 meters (10 feet) long and 2 meters (6.5 feet) high. The front and back walls would be 2.5 meters (8 feet) by 2 meters (6.5 feet). For the roof, I’m considering 16mm (0.6 inch) twin-wall polycarbonate panels. It doesn’t have to carry a lot of load but should be stiff enough to accommodate two small 100 x 80 cm (39 x 31 inches) windows and a standard balcony door. The interior will be tiled, and the exterior will be covered with facade plaster.

Would such a structure of this size, built purely from XPS, be feasible?

Attached are some images of the Styrodur house from a 2013 post.

Thanks in advance for your help

Best regards,
Basti

The "Building Plan" for the Project