Independent report

Executive summary

Published 14 October 2026

Applies to England

The findings in this report support the option to improve the guidance in Approved Document K for general access stairs.

The aim of improving the guidance is to:

• reduce the risk of falls on general access stairs
• reduce the confusion caused by the current stair category definitions and their limited scope of application

The Building Safety Regulator (BSR) has a duty under the Buildings Safety Act 2022 to keep the safety and standard of buildings under review.

BSR is considering extending a previously published report to include general access to stairs and utility stairs. These are stairs located in and around buildings other than dwellings. The project is limited to 2 objectives.

Objective 1

Objective 1 assesses evidence that supports the proposal to revise guidance for general access stairs in Approved Document K. The proposal would align guidance with British Standard 5395-1:2010 for normal use stairs.

The assessment focuses on how the following changes could affect risk:

• increasing the minimum going to 300 millimetres (mm)
• increasing the range of acceptable rise heights to a maximum of 180mm
• increasing the minimum number of steps in a flight before an intermediate landing is required

Objective 2

Objective 2 examines the difference between private stair guidance given in British Standard 5395-1:2010 and guidance for utility stairs in Approved Document K.

It considers the potential number of descents that might occur on these stairs, and how stairs used less frequently could have less restrictive dimensional criteria without increasing the potential risk compared to more frequently used general access stairs.

For general access stairs, this report considers the range of rise and going recommendations made in British Standards and Approved Documents since 1977. Step dimensions were consistent until the introduction of Approved Document M, which sought to provide access for people with disabilities.

The report shows the increased range of stairs that can be built by increasing the range of rises from 150mm to 170mm to 130mm to 180mm, and presents evidence suggesting that this has little effect on overall risk. It also shows how increasing the number of steps in a flight can offset any additional cost of increasing the size of the minimum going. Further research is required to determine whether this change in rise would increase the risk to people with ambulant disabilities.

The evidence in this report suggests that increasing the minimum from 250mm to 300mm would have a dramatic effect on the risk of a large overstep in descent, known to be a leading cause of falls on stairs. It has the potential to reduce the risk of all falls on stairs by up to 80%.

For utility stairs, this report highlights how increasing the rise from 190mm to 200mm would have a negligible effect on the risk of a large overstep and the overall risk of a fall in descent. The report also shows that increasing the number of uses of a stair is likely to increase this risk. Increasing the minimum to 275mm, while keeping the maximum rise at 190mm, would therefore reduce the risk of a large overstep when the frequency of use is below 12 uses per day on average, to values similar to the risk associated with 75 or more uses per day on a general access stair.

Where a proposed utility stair is likely to have more than 50 descents per day on average, it may be appropriate to use dimensions like those recommended for general access stairs. Suggested wording to describe which stair to recommend is provided in the conclusions to this report.