Replacing an existing washbasin that is old, cracked or ugly is a simple procedure because you can utilize the existing plumbing and drainage. If you are installing a washbasin in a room that has never had one, then you'll need to think about running new pipes. How the wastepipe runs to the vertical stack must also be taken into account: it must have a minimum fall or slope of 6mm (1/4in) for every 300mm (1ft) of pipe and should not be longer than 3m (10ft). In a straightforward replacement, there's no need to worry, as you'll be using the wastepipe that already exists.
When connecting new washbasins to your existing pipes, be aware that the sizes and materials may not match. You could find pipes in a variety of materials, especially if it is an older house. Modern plastic pipes are not yet standardized so those supplied by one manufacturer might not be compatible with another's. Adaptors can be purchased for joining pipes of different materials, and also for joining new metric pipes to old imperial-sized ones.
When you choose a new washbasin, you'll need to decide on the type you want: wall-hung or pedestal are the most common types in domestic use. The hollow pedestal provides a little support for the basin, but mostly it just conceals the pipe-work. Old-style wall-mounted wash-basins were often hung on large metal brackets, but modern ones generally have concealed wall mountings. You will need to make sure, however, that the wall is strong enough to support the weight of the vitreous china they are made from. Make sure that the basin has holes at the required spacing to take the taps - you'll probably want to replace these as well - or none at all if the taps are wall mounted. When you buy a new washbasin and taps, it's a good idea to 'dry test' them: bend over the basin and imagine you are washing your face. Make sure you can get both hands in the bowl.
