The walls of the bio-coldframe are formed in the subsoil by kerbstones. On the south side, there is located on this in cement a 50 cm high window, framed in a two-part steel frame, which is double-walled plexiglass on the outside and wired glass (diffuse light incidence) on the inside. The remaining sides are formed by wooden planks provided with a bio-paint coating. The interior is designed with unrottable coconut fibre mats (instead of heat packing or ground heating device), over which a double-galvanised narrow-meshed wire netting is laid, which is nailed to the wooden walls with staples and, on the south side, is bent over the coconut fibre mats 5 cm above the kerbstone upper edge. 2.5 cm below the coldframe upper edge, roof battens are nailed in each case on the longitudinal sides on the squared timbers situated in the corners and in the wall centre, as support for the (removable) transverse battens which end flush with the frame upper edge. The coldframe covering consists of pink slotted film. For ventilation, this can on both longitudinal sides be folded around the roof battens resting thereon for wind protection, after these have been pushed approximately 10 cm towards the frame centre. For freedom from maintenance for a number of days, transverse battens are placed between frame upper edge and slotted film, as a result of which lateral air circulation is ensured.
