This is important if the landlord keeps your deposit claiming that you owe rent. When there is accidental damage it would probably be reasonable for a landlord to keep some of the deposit to pay for cleaning or replacement. You may also find that you lose a deposit if you leave without giving enough notice, or before an agreed date. It is probably unreasonable for a landlord to keep money for steam cleaning curtains or carpets that you haven't damaged, unless it was part of your original agreement. It would be unreasonable for a landlord to keep money to replace old furnishings that have simply worn out.
Some tenants withhold the last month's rent to the equivalent of the deposit when they leave.
This covers you if the landlord refuses to return the deposit. Poor conditions can affect your health and make your home a 'statutory nuisance'. This term covers conditions such as dry rot, smoke or noise pollution, burst pipes, falling plaster, defective wiring, mould growth, damp, condensation and leaking roofs. Under the Environmental Protection Act 1990 councils have very strong powers to deal with poor conditions in your home. It is your landlord's duty to carry out repairs.