There are two types of stairlift. Straight and curved. The first is designed for straight stairs. The footrest of the lift will normally stop level with the top stair. It may be possible to use a straight stairlift on some configurations of curved stairs.
The second, and generally far more expensive type, is a 'made to measure' or 'curved track stairlift' which can travel around bends on the stairs and can be made to run on to the landing. Prices vary according to the length of the stairs, the number of bends and the complexity of the bends.
It is worth noting that although far more expensive, the resale value is negligible, as the rail is made to measure and can only be re-installed on an identical staircase.
Curved track stairlifts can be fitted on either side of the stairs, the layout of your staircase will determine which is most suitable. If you need a curved track stairlift you will need to pay a deposit to the company that you are dealing with. This will normally be about 30% of the cost of the lift. The deposit is required because the company are committing themselves to building a stairlift rail that will only fit into your house. You should not have to pay a large deposit if you order a standard straight lift as these can usually be adapted to suit another staircase.
In certain circumstances it is possible to fit a straight stairlift on stairs that have a turn at the top. For example if you have a straight run of stairs with three steps winding onto the landing. Or a straight flight and a quarter landing with two more steps, a folding platform stairlift could be the solution. A straight stairlift is installed with extended legs, so the footrest stops in line with the landing. A solid wooden platform is then built around the footrest of the lift. This platform can then be used to walk safely onto the landing. The platform is hinged so that it can be folded back against the wall to enable other people in the house to use the stairs.
It is also possible to have a powered platform so the user doesn't have to bend to raise it. Please note that the folding platform option is not suitable for everyone. If you are prone to dizzy spells or feinting or if you have very poor mobility this is not a viable option. Seek independent advice.
Christian Dunnage is a director of Dolphin Mobility Ltd, a UK based independent supplier of stair lifts and mobility products http://www.dolphinlifts.co.uk and author of http://www.stairlift.co.uk an impartial online guide to having a stair lift in your home.