How much space does a staircase need?
Written by Scott Jones, The Stair Guys, independent staircase measuring and sourcing specialists·Last updated
"Will a staircase fit" usually comes down to one thing: floor length. A staircase is not just the hole in the ceiling, it is the run it takes along the floor to climb at a safe angle, plus somewhere to stand at each end. Here is roughly what that is, and what your options are when the space is tight.
The run of a straight flight
The floor length a straight flight needs is simple to work out: the number of risers minus one, times the going (the depth of each step). A typical stair to a normal storey of about 2.6 metres has 13 risers, so 12 goings. At a comfortable 250mm going that is 12 x 250 = 3000mm, about 3 metres. At the minimum 220mm going it is 2640mm, and a gentler, deeper going needs more again. So a straight flight generally wants around 2.6 to 3 metres of clear run, and a longer one if you want a shallow, easy stair. There is a full worked example in a compliant staircase, drawn out, and how to set it out in how a staircase is measured.
The bits people forget: landings and the opening
The flight is not the whole of it. You need clear landing space at the bottom to step onto the stair and at the top to step off it, each at least the width of the stair, and neither is counted in that run figure. Above the stair you also need the stairwell opening in the floor above, long enough to keep 2 metres of headroom the whole way up. Miss either and a stair that fits the run on paper still does not work, which is covered in why a staircase that works on the plan can fail in reality and headroom.
When the run is not there
If you do not have the length for a straight flight, you have real options, in rough order of how much space they save:
- Turn it. An L-shaped (quarter-turn) or U-shaped (half-turn) staircase folds the run into a corner or back on itself, so it needs less floor length, though it needs the width for the turn and a landing.
- Winders, but know what they really do. Tapered treads turn the corner without a flat landing, which saves the landing's floor space. What they do not do is make the staircase shorter, which is a common misconception: a winder turn is usually longer overall than the straight equivalent. The gain is avoiding the dead space of a landing, not shrinking the stair.
- Go spiral. A spiral around a central column has the smallest footprint of any normal stair, for where space is very tight.
- Space-saver, as a last resort. An alternating-tread stair is steeper and only allowed in limited cases. See space-saver stairs.
The full menu of shapes is on types of staircase.
The one thing you cannot do
What you cannot do is make a staircase shorter in the same footprint by making it steeper. A stair has a maximum pitch of 42 degrees, and a straight flight already close to that has nowhere left to go. Shallower, more comfortable stairs need more length, not less, so if the run is not there the answer is to turn the stair, shrink the type, or open up the space itself by moving a wall, a door or the floor opening. A stair does not magically get shorter in a space that is too small; that is a physical impossibility, and it is exactly the kind of thing a site survey settles before anyone builds.
Frequently asked
How much space does a staircase need?+
A straight flight for a normal storey needs roughly 2.6 to 3 metres of clear floor length, worked out as the number of risers minus one times the going, and a gentler, deeper-going stair needs more. On top of that you need clear landing space at the top and bottom, and the stairwell opening above for headroom. Where the run is not available, the stair is turned into an L or U shape, given winders, or made a spiral.
What is the minimum space for a staircase in the UK?+
There is no single minimum, because it depends on the storey height and the going. At the tightest, a straight flight to a normal storey needs a little over 2.6 metres of run at the minimum 220mm going, plus landings and the opening. Below that you move to a turned stair, winders or a spiral. A space-saver is the last resort in genuinely tight, limited cases.
Can you make a staircase steeper to fit a smaller space?+
Only up to the limit, which is a 42 degree pitch, and most stairs are already near it. You cannot keep making a stair steeper to fit a shorter run, because past 42 degrees it is not legal. A shallower, more comfortable stair needs more length, not less, so if the space is not there the real fix is to turn the stair, use a smaller-footprint type, or open up the space by moving a wall, door or the floor opening.
Do winder stairs save space?+
Not by making the staircase shorter, which is a common misconception. A winder turn is usually longer overall than a straight equivalent. What winders save is the flat landing that a turn would otherwise need, so they help where there is no room for a landing, rather than by shrinking the stair itself.
Related guides
- Why an online stair designer can get it wrongAn online stair designer works from what you type in and quietly assumes square walls, allowed-for plaster and floor finishes, fine headroom, and that you know the regs. Here is what it misses, and why the final order should come off a site measure.
- Why a staircase that works on the plan can still fail in realityA flat plan cannot show headroom, buildability or the real millimetres. Here are the staircase mishaps a drawing hides, from headroom and door swings to winders, the wrong stair category and newel posts, and why a site survey catches them.
- How a staircase is measured: total rise, going and step countA staircase is set out from the total rise, the finished-floor to finished-floor height, divided into an equal number of risers, then the going is set so the pitch and 2R plus G stay in range. Getting the finished floor levels right is the part that catches people out.
- Are my stairs too steep, and can you make them less steep?Stairs feel too steep when the pitch is close to or over the 42 degree legal maximum, and they are often that way because the space forced it. The catch is that making a stair shallower needs more floor length, not less, so you cannot shallow it in the same footprint. To genuinely fix a steep stair you have to open up the space, moving a wall, door, the floor opening or joists.
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