Wood: the hut is made of pine solid wood 18 mm thick. Weather protection glaze in carbibol. Opening: no cat flap was deliberately used, as i have found that my cats prefer an open entrance. The opening is 15 cm wide and 17 cm high. In addition, some fresh air comes in, whereby a hut with cat flap is very airtight, which can lead to a lack of oxygen.Insulation: as insulation, the inside (wall, floor, ceiling) was covered with felt. Felt provides good thermal insulation, the cats find it cuddly and unlike styrofoam, it withstands cat's claws. Roof: the roof is clad with roofing felt and can be removed upwards. The hut stands on 4 feet so that no cold and wetness from below can pull into the wood. Heating: a splash-proof underfloor heating has been incorporated into the insulation of the floor, it has a power of 12 watts and simply has to be plugged into the socket. Everything assembled, ready to set up.