A thick underlay will help protect a carpet by absorbing some of the wear. Buy the best you can afford - preferably rubber crumb or felt. It is almost more important for the underlay to be fitted professionally than the carpet, because any gaps will cause uneven wear in the carpet.

Carpet prices start from pounds 4 per square metre for a nylon lightweight tufted carpet to around pounds 50 per square metre for a traditional woven Wilton or Axminster. Areas which suffer heavy traffic should be covered with Heavy Domestic. You can get away with a cheaper carpet in the bedroom.

A good quality 80 per cent wool/ 20 per cent nylon carpet will last between 10 and 30 years, depending on wear, if looked after - vacuumed and lightly cleaned regularly.

Bare floors of any sort are healthier in the bedroom, but if they are then covered by heavy wool rugs they will still harbour dust mites.

lThe National Asthma Campaign recommends short pile synthetic carpets. Dust mites thrive in wool, but fresh air and regular vacuuming will limit contamination.

Think hard about the dangers of ceramics or stone at the foot of the stairs if you have small children. A carpet with underlay provides a much softer landing.