1. The standard bath is 180cm long, but you can get longer ones - 200cm - or shorter ones - down to 120cm or four feet. Most plumbers' merchants carry only a limited range of baths, so take your time and look around. Ask for catalogues from Italy and Germany.
2. Old British baths were made of cast-iron, and are prized for their antique value, but they are very heavy, take the heat out of the water, are difficult to keep clean and are often uncomfortable. Most modern baths are plastic - these tend to move around and are difficult to seal at the edges. Steel is slightly more expensive than plastic but much better quality.
3. If you think your shower room is too small to accommodate a bath, think about enlarging it. Most modern flats have internal partition walls made of timber studwork and plasterboard; these can be moved quite easily.
4. Check that the floor is strong enough to take the weight of a bath full of water; your local building control department should be able to advise. Any problems can usually be solved by doubling up a few floor joists.
5. Traditional baths slope towards one end, where the plug-hole and taps are, and are rounded at the bottom, which makes it uncomfortable to stand in them when showering. Two-person baths, with the plughole in the centre, are much more comfortable. If you get one without pre-drilled holes you can fix the taps and shower outlet to the wall at any point around the bath. Bette Baths, from Germany, do a good range of steel baths.