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How steep should a staircase be?

14 August 2019

Steep staircases in older homes can be a bit of a nightmare to use, feeling like a mountain climbing expedition on the way up and a balancing act on the way down! If you’re adding a staircase to a new or existing space, it makes sense to ensure that it is safe and simple to get up and down. At the same time, you don’t want the angle to be too gradual causing it to take up an unnecessary amount of floor space.

Here at British Spirals & Castings, we will help you to fully understand the options for your space and to find the best type, style and angle of staircase for you. If you’re just trying to get an idea of the options, however, then a good place to start is the Building Regulations and Standards here in the UK.

What is the best angle for a staircase according to the Building Regulations?

The regulations for UK stairs are covered by Approved Document K in England and Wales and Technical Handbook 4 – Safety in Scotland. They don’t simply set a recommended angle for the staircase but also lengths for the ‘Going’ and ‘Rise’ shown in the diagram below:

Measuring going and rise

How steep should a straight staircase be?

A building regulations requirement is that the going and rise lengths should be the same along the full flight of straight stairs. The exact requirements for the angle (pitch), rise and going are slightly different depending on where the staircase is being installed and there are parameters in which we need to work.

Straight staircase for a home

If you’re adding a staircase to a home, then this is classed as a ‘private stair’ and the requirements are shown below:

RegionMin. rise (mm)Max. rise (mm)Min. going (mm)Max. going (mm)Max. Pitch
England & Wales15022022030042º


To ensure the overall step size is comfortable it is also recommended that the total measurement of twice the rise plus the going (2R + G) should be between 550 mm and 700 mm. To show how this might work on a staircase we’ve included an example of a straight staircases below:

Step Size

Straight Staircase for other buildings

If you’re dealing with straight staircases in any other building, including access staircases to multiple flats, then the requirements are slightly different:

RegionStaircase TypeMin. rise (mm)Max. rise (mm)Min. going (mm)Max. going (mm)Max. Pitch
England & WalesUtility150190250400
General Access150170250400
ScotlandGeneral Access10017025034º


Note: If you’re fitting a staircase in an existing building then you may be able to get a little wiggle room but this will be at the discretion of building control so get in touch.

Again, it is recommended that the total measurement of twice the rise plus the going (2R + G) should be between 550 mm and 700 mm. The staircase shown above would meet all of these requirements.

How steep should winder stairs & curved staircases be?

If you’re going for a staircase with a tapered tread then in addition to the requirements for a straight staircase, there are also a couple of other things to take into account.

For winder and combination staircases, the minimum width at the narrow end of the tread must be at least 50 mm. The going of the treads (measured at their centre) must also be no less than those of the straight treads and should be identical for all tapered treads as shown in the example below:

Winder staircase angle

For stairs with treads one metre or wider, the going is measured 270 mm in from the tread edge on either side. These must meet the requirements for straight staircases and be the same distance all the way up.

Stair width

How steep should spiral stairs and helical staircases be?

Finally, for spiral and helical staircases, there are separate requirements within BS 5395-2. There is no minimum or maximum angle for these staircases but there are clear limits for the going and rise.

The going of spiral staircase is measured in the centre of the tread and at either side 270mm from the tread edge (see below)

spiral staircase going measure

The requirements for the going and rise are then dependent on the location of the staircase, and what it is used for as shown below:

Stair categoryRise (mm)Min inner going (mm)Min centre going (mm)Max outer going (mm)
Small private spiral staircase — used by a limited number of people e.g. a staircase in a home which doesn’t go to a communal room like a kitchen or an access stair to a small room not used by the public for a commercial property.170 – 220120145350
Private spiral staircase — a main staircase within a home170 – 220120190350
Small semi-public* spiral staircase — used by a limited number of people such as a communal staircase leading to more than one flat.170 – 220150230350
Semi-public* spiral staircase — used by a larger number of people such as a stair serving a large area in a factory, office or shop.150 – 190150250450
Public spiral staircase — intended to be used by large numbers of people at the same time (meaning room is needed for passing).150 – 190150250450


For all these staircases, the total measurement of twice the rise plus the going (2R + G) should be between 480 and 800 mm.

Finding the right fit for you

Whatever you project is, we can help you to find the perfect staircase for you. To help get an idea of the design you’d like, take a look at the pictures in our gallery then send us a quote! We look forward to hearing from you soon.





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