People ask this constantly, usually after somebody has told them their hallway is too tight. The short answer is that it fits far more often than not.
The useful question is not “how wide are my stairs” but “how much walking room is left when the lift is parked.”
What actually takes up the space
A stairlift at rest is a folded seat against a rail. The seat, arms and footrest all fold up. What remains is the rail itself and the folded carriage, and that is a narrower object than most people picture.
The Harmar Pinnacle SL300 is the model we specify most often where clearance is the problem. It takes roughly 10.5 to 11 inches of stairwell when folded, which is why it exists.
The things that genuinely cause trouble
In our experience it is rarely the width of the flight. It is usually one of these:
- A door at the bottom that opens across the stairs. Solvable, often by choosing which side the rail runs on, sometimes by a hinged rail section.
- A radiator or newel post at a landing. Measured at survey and worked around.
- A doorway at the top too close to the last step. This one decides the parking position, which is a real design decision rather than an afterthought.
Which side should the rail go on?
Generally either. Which side is a real decision and it depends on the handrail, the doorways at each end, and crucially which way the person transfers on and off. Somebody with a weaker left side wants to get on and off a particular way, and that should drive the answer rather than convenience for the installer.
What we do about it
We measure the clearance that will be left and tell you the number before you buy, not after. If it is genuinely too tight, we say so. Occasionally the honest answer on a very tight flight is a platform lift in a different location, or a ground-floor rearrangement.
If you want a quick read before anybody comes out, send a photograph from the bottom of the stairs looking up and one from the top looking down. That tells us most of what we need.
Harmar states the Pinnacle SL600 folds to 10.5 inches of staircase width. Bruno lists the Elan rail as a narrow vertical design for the same reason.
Measure it yourself in two minutes
You do not need us to get a rough answer. Take a tape measure to the narrowest point of the flight, usually partway up rather than at the bottom, and measure wall to wall. Write that number down.
Now subtract roughly eleven inches for the folded lift. What is left is your walking room. Most people find they have more than they feared, and building codes generally put residential stair width at 36 inches or more, which leaves a usable gap once a slim lift is parked.
Harmar publishes the Pinnacle SL600 as folding to 10.5 inches, and Bruno designs the Elan with a narrow vertical rail for the same reason.
What we have actually had to turn down
It is rare, and when it happens it is usually one of three things. A spiral staircase so tight that the rail cannot follow it. A flight where the only viable rail position runs straight through a doorway at the top. Or a staircase with open risers and no solid tread to fix into.
Even then there is often another answer. A platform lift in a different part of the house, a ground-floor rearrangement, or occasionally the honest conclusion that this house is not going to work and we say so.
Narrow stairs and the person on them
There is a second question people forget. A narrow staircase usually means a narrow landing at the top, and the landing is where the transfer happens. Powered swivel seats exist precisely for this: the seat turns toward the landing so somebody steps off facing forward rather than sideways in a tight space.
On a cramped landing that option is worth more than it costs, and it is the kind of thing that gets left off a quote by whoever is trying to be cheapest.
If the stairs are only part of it
Narrow hallways and doorways come with narrow stairs. If getting a walker or a rollator through the house is also difficult, a narrower frame or a different style of aid sometimes solves more than the stairs do. Those you can order directly from our shop, delivered free, without an appointment.
Doors at the bottom of the stairs
This is the most common genuine obstacle on a narrow flight, and it has a specific solution. A hinged or folding rail section lifts the last piece of track out of the doorway when the lift is parked, so the door swings normally.
It has to be specified with the lift rather than added afterward, which is why it belongs in the survey conversation. If a quote for a narrow staircase with a door at the foot does not mention it, ask why.
Two straight lifts on a narrow flight
Where a narrow staircase has a proper landing, two straight lifts sometimes beat one curved rail on cost. On a narrow landing it is usually the wrong call, because the transfer between them needs room to stand and turn that a tight landing does not have.
We would rather lose the cheaper sale than put somebody through a transfer they cannot do safely twice a day. Our curved stairlift page sets out when the manufactured rail is genuinely the answer.