There are two types of stairlift. Straight and curved. The first is designed for use on straight staircases. The footrest of the stairlift will stop level with the top stair. It may be possible to use a straight stairlift on some configurations of curved stairs.
For example if you have a straight staircase with three steps at the top which wind onto the landing, then a folding platform stairlift could be the solution. A straight stairlift is installed with extended legs at the top of the rail, so the footrest stops in line with the landing. A platform is then built around the foot rest of the stairlift. The 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.
The option of a powered platform is available which means the user doesn't need to bend down to raise it. The following video features the automatic powered folding platform manufactured by Meditek.
The folding platform option is not suitable for everyone. If the user of the stairlift is prone to dizzy spells or feinting or if you have very poor mobility this is not a viable option. Seek independent advice from more than one source.
The second, far more expensive type of stair lift, is a 'made to measure' or 'curved track stairlift' which can travel around bends on the stairs and can be designed to run on to the landing. Prices will vary according to the length of the rail required, the number of bends and the complexity of the bends.
It is worth noting that although far more expensive, the resale value of curved stairlifts is negligible, because the rail is made to measure and can only be used again on an identical staircase.
Curved track stairlifts can now be installed on the inside bend or the outside bend of the stairs. The layout of your staircase will determine which is most suitable.
If you need a curved track stairlift you will have to pay a deposit to the company that you are dealing with. This will normally be about 30% of the cost of the stairlift. The deposit is required because the company are committing themselves to building a stair lift 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.
For stairs with a well sized half-landing it may be possible to install two straight stairlifts.