Kevin Underwood of the British Woodworking Federation (BWF) discusses the key components for construction of safe staircases,, and the regulatory background.
For many homes, a staircase not only provides a functional role, it’s also a central feature of a property.
While staircases are an important functional and aesthetic feature, they pose a major safety risk. The Royal Society for the Prevention of Accidents (RoSPA) found that every year there are over 700 fatalities and more than 300,000 A&E attendances due to falls on stairs in the home. In fact, 84% of injuries on stairs occur in the home.
In this article we will explore the key considerations of a safe staircase design, how Building Regulations are evolving to help reduce accidents in the home, and what this means for housebuilders and developers in meeting new standards.
SAFE STAIRCASE DESIGN
There are many factors that impact the safety of a staircase, revolving around two key areas: the ‘rise’ and ‘going.’ A general rule is that the dimensions of the rise and going should allow a natural stride – helping ensure that the user does not need to overstretch or take unnecessary small steps. The best way to do this is to keep the going over 250 mm, and the rise of the stairs as consistent as possible.
The nosing of each stair should also be visible so the user can easily identify each step. For patterned or tiled stairs, using a separate colour or material can help the nosing stand out. In addition, the nosing should not extend too far over the step beneath it, as this can produce a trip hazard.
The finish and slip resistance of the staircase should also be considered. If the going of the stair is 300 mm or more, the slipperiness of the surface is less of a safety factor, but for stairs with smaller treads, the slip resistance should be considered. The nosing is where first contact is made when descending the stairs, and a slip resistant material can help prevent falls.
To help prevent accidents, handrails and guarding should also be incorporated into the staircase design. In addition to being an attractive design feature, handrails offer extra safety support and should be installed where there is a rise of over 600 mm. If the stair width is more than 1,000 mm a handrail should be fitted on both sides. The handrail should be within easy reach at all points on the staircase and positioned 900-1,000 mm above the pitch line of the stair or floor.
The handrail can also form the top of the stair guarding. Guarding helps prevent falling over the side of a stair and is required for staircases at any height over 600 mm, or where there are two or more risers. The guarding could be a screen or balustrade, but it must be high enough to stop people falling over it and strong enough to withstand someone falling into it. For buildings where the stair is used by children, the gaps in the guarding should be less than 100 mm to reduce the risk of children falling through or becoming trapped in the guarding.
Following these practices will help ensure a staircase is as safe as possible. In fact, research has shown that stairs produced in line with the British Standard code of practice for the design of stairs (BS 5395-1:2010) could result in 60% fewer falls. Not only would this save many lives, but it would also reduce the burden on A&E departments and limit the impact that a serious accident on the stairs can result in.
EVOLVING SAFETY REGULATION & ITS POTENTIAL IMPACT
At the BWF we’re working with the Department for Levelling Up, Housing and Communities (DLUHC) on a revision to Approved Document K (AD K) for Requirements K1 and K2. AD K covers protection from falling, collisions and impacts in and around buildings, while Requirement K1 states stairs shall be designed, constructed and installed to be safe for people moving between different levels. Requirement K2 outlines that stairs should be provided with barriers where it is necessary to protect people from falling.
Based on research by the Building Research Establishment (BRE) which demonstrated that stairs, including those that conform to existing building regulations, could be changed to reduce the number of accidents that occur on them, BS 5395-1 has been developed.
BS 5395-1 recommends several key changes for private stairs including that there should be graspable handrails on both sides of the stair, and that the minimum going for a private stair should be 250 mm and the maximum rise 200 mm. In addition, the changes would set out a new maximum staircase pitch at 38.5 degrees, a minimum clear width measured between handrails of 800 mm as well as ensuring the walking line of the winder is centred on the newel post.
If these changes are introduced into AD K, housebuilders and developers will need to dedicate more space to the stairway as the stairs will become both wider and longer. In turn, this could mean that house designs would need to be revisited and plot sizes made bigger, or room sizes reduced.
By working in collaboration with stair manufacturers and housebuilders and developers, the BWF hopes to develop AD K guidance to maximise staircase safety, while minimising the impact on the housebuilding industry.
Kevin Underwood is technical director at the British Woodworking Federation (BWF)