bearing. The pivoting frames are based on the forster unico profile. Forster does not rely on plastic insulators, which sit between the inner and outer strip galvanised steel frames, but on a high-quality [...] steel window construction, the frame corners are not bevelled but welded into one unit. As a result, there are no butt joints through which moisture can penetrate into the frames. Their surfaces were finished [...] pivoting casement windows, each measuring H 1853 mm × W 1310 mm, are quite heavy at 250 kg and the outer frame weighs a further 50 kg. "Instead of placing the units weighing a total of 300 kg on the pumice parapets