How to Measure Your Stairs for a Stairlift

You only need one tool: a good metal tape measure, ideally 5 metres long. A fabric or cheap retractable tape will sag along the staircase and give you inaccurate readings - metal is more reliable.

It helps to have a second person with you to hold the tape at the top while you read it at the bottom. A notepad or phone to record measurements as you go avoids the need to repeat steps.

For curved staircases with bends, turns, or intermediate landings, a professional survey is genuinely necessary. Self-measurement on a curved staircase is difficult to do accurately and the numbers you get will not be precise enough to manufacture a bespoke rail. Straight staircases are straightforward to measure yourself.

Stand at the bottom of the stairs and look up. Decide which side the stairlift rail will sit on - left or right.

In most homes with a wall on one side and a banister on the other, the wall side is the safer and more common choice. The rail fixes to the stair treads, not the wall, but proximity to a solid surface helps users feel more secure when getting on and off.

If you have walls on both sides, choose whichever gives easier access from the bottom - usually the side closer to the living room or most-used room on the ground floor.

Note any obstacles on each side: radiators, doorways that open onto the stairs, built-in shelving, or low windowsills. These will affect which side works and whether any modifications are needed.

This is the most important measurement. Stand at the top of the staircase and run the tape measure down so it lightly touches the edge (nose) of each step in turn, all the way to the floor at the bottom. Do not measure in a straight diagonal line - the tape should follow the profile of the steps.

Record the measurement from the top stair tread to the ground floor area beyond the bottom step. This is the floor-to-top-nose measurement and tells the supplier how long a rail is needed.

A standard domestic staircase is usually between 2.5 and 4 metres measured this way. If you are getting a rough telephone quote, this is the single most useful number you can provide.

Measure the width of the staircase at its narrowest point, from skirting board to skirting board (not wall to wall - the skirting adds a few centimetres that matter).

Most stairlifts need a minimum clear width of around 600mm (just under 24 inches) to fit safely. Standard domestic staircases are usually 750mm to 900mm wide, which is fine for most models.

If your staircase is narrower than 700mm, you will need a slimline stairlift model. These exist and work well, but there are fewer options and some features (wider seats, powered swivels) may not be available in slimline versions.

Measure at two or three points along the staircase, not just at the bottom. Some older properties have staircases that narrow slightly higher up due to period construction.

When the stairlift is parked at the bottom, the carriage extends beyond the last step into the hallway. You need enough space for this to happen safely, and for the user to get on and off without obstruction.

Measure from the riser (front face) of the bottom stair tread to the nearest obstacle - a door, radiator, wall, or cupboard. You need a minimum of around 450mm to 500mm (18 to 20 inches) for the lift to park safely and the user to board comfortably.

Less than 300mm (12 inches) and you will almost certainly need a hinged rail. A hinged rail lifts up when not in use so it does not block the hallway or create a trip hazard. It adds to the cost but solves the problem cleanly.

The same principle applies at the top. Measure from the nose of the top stair tread to the nearest obstruction - a wall, door, or banister post. You need enough room for the carriage to park and the user to stand and step off safely.

Most stairlift rails extend about 200mm (8 inches) past the top tread onto the landing. If a door opens directly onto the top of the stairs, this needs to be noted - some installations require the landing door to be rehung or a different parking position arranged.

With the staircase length, width, bottom clearance, and top clearance in hand, you have enough to get a rough telephone quote from most suppliers. Some companies can give indicative pricing over the phone from these four numbers alone.

When you share your measurements, also mention:

• Whether the staircase is straight or has any bends
• Which side the stairlift will go on
• Any obstructions you noted - radiators, doors, newel posts
• Any other stairs in the house (some homes have a small step from the hallway up to the main stairs that the survey needs to account for)

Remember that a telephone quote is not a final price. A home survey is still required before any stairlift is ordered, particularly for curved staircases and any installation where the measurements are close to minimum clearances.