Will a Stairlift Fit My Stairs? How to Measure, With Every Staircase Layout

Before anyone comes to measure, most families want a simple answer: is a stairlift even possible on our stairs? This guide shows you how to check in about ten minutes, explains what each staircase layout means for the type of lift, and compares the space each common UK model needs, using the manufacturers’ and dealers’ own published figures. A surveyor always confirms the final answer, but you will know what to expect.

What decides whether a stairlift fits

Width is what people worry about, but it is only one of six things. A stairlift needs a clear line for the rail, enough width for the seat and the user’s knees, somewhere to park at the bottom, room to get off safely at the top, a staircase within the model’s angle limit, and a power supply. On most British staircases all six are met. Where they are not, it is usually the space at the top or bottom rather than the stairs themselves.

How to measure your stairs in ten minutes

You need a tape measure and someone to hold the other end. Write the figures on the measuring sheet further down this page.

1. Usable width at the narrowest point. Measure from the wall to the inside of the banister, or to the newel post, at about knee height when sitting. Handrails, skirting boards and radiators all reduce it.
2. The length of the run. Measure along the stairs from the floor at the bottom to the top step nosing, or count the steps.
3. Space at the bottom. Measure from the bottom step to the nearest obstruction straight ahead, such as a front door, wall or radiator. This is where the rail ends and the chair parks.
4. Space at the top. Measure the depth of the top landing. The seat swivels here so the user can step off onto the landing rather than the stairs.
5. The steepness. Measure the height of one step and its depth. A surveyor will calculate the angle, but writing both down lets you check it against the table below.
6. Headroom and power. Note any low ceiling over the stairs, and where the nearest socket is at the top and bottom.

What “usable width” means

The width that matters is the clear width the chair and the user’s legs travel through, not the wall-to-wall width of the stairwell. A 760mm staircase with a chunky handrail and a newel post can have less usable width than a plain 700mm one. If your stairs are very tight, measure in several places and use the smallest figure.

Doors and hallways at the bottom

The commonest problem is a door or hallway right at the foot of the stairs, where a standard rail would stick out. Hinged and folding rails solve this: the end of the rail folds up out of the way when the chair is upstairs. They add to the price, so mention them when you ask for quotes.

Your staircase layout

The shape of your stairs decides whether you need a straight or a curved stairlift, which matters more for the price than any other single factor. Straight lifts are made from standard rail cut to length. Curved lifts have a rail designed and made for your staircase.

Straight flight

One flight with no turns takes a straight stairlift. This is the most common British layout and the easiest to fit, often in a few hours.

Quarter turn with a landing

A 90-degree turn at a landing, at the top, bottom or part way up, usually needs a curved rail. If the landing is at the very top, a straight lift that stops before the turn may work, provided the user can step off safely there.

Half landing

Stairs that turn back on themselves at a half landing take one continuous curved rail. Two straight stairlifts, one per flight, can cost less, but the user has to move from one chair to the other on the landing. Our guide to two straight stairlifts or one curved explains when that works.

Winder steps

Winders are wedge-shaped steps that take the stairs round a corner without a flat landing. They are common in older terraced houses and need a curved rail. They also make the inside of the turn tight, so the surveyor will check the rail can run on the outside.

Several turns and landings

A single curved rail can follow several turns and intermediate landings. See our guide to stairlifts for multiple turns and landings.

Spiral or helical stairs

Spiral stairs are the hardest layout. Some curved models can follow a spiral, but the tight inner radius and narrow treads rule many out. Our guide to stairlifts for spiral stairs covers the options.

Split levels and short flights

Three or four steps between levels can take a short straight rail. For a wheelchair user, a step lift is usually the better answer; see our guide to platform and wheelchair lifts.

How much space each model needs

These are the published figures we found for common UK models. Makers measure folded width differently (some to the footplate, some overall), so treat small differences with care, and always confirm with the installer. “Not published” means we could not find the figure from the maker or a dealer.

Sources and dates for every figure are listed at the end of this page. For weight limits, seat options and prices by model, see our stairlift specifications guide and the slimmest stairlifts page.

Steep stairs

For new homes, Approved Document K sets a maximum pitch of 42 degrees for a private stair. Older houses can be steeper, but the stairlifts in the table above are rated for angles from 50 to 72 degrees. That means a steep staircase is rarely what stops a stairlift. If yours is unusually steep, give the surveyor the step height and depth when you book, so they bring a model that suits it.

Will other people still be able to use the stairs?

Usually, yes. With the seat, arms and footrest folded, most models stick out about 285mm to 405mm from the wall, according to the figures above. On a narrow staircase that can leave a tight gap, so think about who else uses the stairs, especially children, other older relatives, or anyone carrying laundry. A perch (standing) lift takes less room; see our standing stairlifts guide.

For new or adapted homes

Homes built to the accessible and adaptable standard in Approved Document M, known as M4(2), must have stairs at least 850mm clear width so that a stairlift can be fitted later, and the higher M4(3) standard also asks for a power socket for a stairlift near the foot or head of the stairs. If you are building or adapting, these figures give comfortable room for any model.

When a stairlift will not fit

A stairlift is unlikely to work if the usable width is well below the narrowest published minimum, if there is no safe place to get off at the top, if the user cannot sit and transfer safely, or if the staircase is a tight spiral. In those cases, look at a through-floor lift, living downstairs, or moving home. Our guide to alternatives to a stairlift compares the costs, and a free occupational therapist assessment will give you an independent view.

What the surveyor checks

A surveyor repeats your measurements and adds the things that need training to judge: the exact rail line on a curved staircase, the angle, the fixings, and how the user sits, stands and turns. Our guide to what happens at a stairlift home survey walks through the visit.

Measuring sheet

Print this page or copy the table, fill in your figures, and have it to hand when you ask for quotes.

Frequently asked questions

What is the minimum stair width for a stairlift?

It depends on the model. The published minimums we found run from 610mm for the Access BDD Flow X and Flow 2 to about 700mm for the Acorn 180. Measure the usable width at the narrowest point, after handrails and newel posts.

Can you fit a stairlift on narrow stairs?

Often, yes. Slimline straight models fold to around 285mm to 320mm from the wall. The problem on narrow stairs is more often the space left for other people to pass than the lift itself.

Can a stairlift go on steep stairs?

Usually. Building Regulations limit new private stairs to 42 degrees, and the models we checked are rated for 50 to 72 degrees. Tell the surveyor if your stairs are unusually steep.

How much space do you need at the bottom of the stairs?

Enough for the chair to park and for the user to sit and stand. One model’s published figure is 660mm. A hinged or folding rail helps where a door is close to the bottom step.

Do winder stairs need a curved stairlift?

Yes, in almost all cases. Winder steps turn the staircase without a landing, so the rail has to curve with them.

Will a stairlift block the stairs for everyone else?

Not usually. Folded, most models sit about 285mm to 405mm from the wall. On a very narrow staircase, check the gap that is left.