Stairs are a necessity in buildings; they provide a path from one level to another level under normal conditions and an exit path under emergency conditions.
In fact, we’ve been building stairs in various forms for thousands of years, so you would think by now we’d have this right, but that might not be the case.
With advances in passenger lift technology, disability rights movements and building code refinements, stairs in larger buildings have now generally been relegated to a secondary path or for emergency use only. But in smaller buildings without passenger lifts, and in residences, stairs remain the sole form of movement between levels of a building.
In 2008, the Australian Building Codes Board commissioned the Monash University Accident Research Centre to investigate accidents in buildings. A paper was released, titled The Relationship between Slips, Trips and Falls and the Design and Construction of Buildings.
The Centre reported some interesting results:
- They found an increase in frequency in fall injuries:
- Stair and step injuries had increased over 70 per cent during the decade from 1993/94 to 2002/03
- Fall injuries in buildings increased by 14.2 per cent over the three-year period from 2000/01-2004/05
- Stair and step injuries increased by 22.3 per cent among those aged 65 years and over in the same three-year period
- Age was seen to play an important factor:
- Persons 65 years and over accounted for 73.3 per cent of hospital visits for fall injuries occurring in buildings, with persons 75 and over accounting for 61.2 per cent
- Those 85 years and over accounted for almost 30 per cent of all hospital visits for falls between 2002/3 and 2004/05
- Gender seems to be a factor too, with females comprising 64.7 per cent of the fall injuries treated in hospital
- Locations of accidents were also recorded, with 62 per cent occurring in the home, 16.2 per cent in aged care facilities, 11.3 per cent in health-care areas, 2.9 per cent in schools and 1.9 per cent in cafes, hotels, and restaurants
- Additionally, the direction of travel was identified, with up to 80 per cent of accidents occurring during stair descent
Using these statistics, it is fair to assume that we will see an increased number of falls associated with older people over the coming decades. Like other parts of the world, Australia has an ageing society and building safer stairs could help reduce the number of accidents in stairs.
Given that falls in buildings has been identified as the leading cause of non-fatal injuries and the second leading cause of spinal cord and brain injuries, shouldn’t we try to design stairs to reduce this risk and improve occupant safety?
The following seven universal design concepts can improve the level of safety and accessibility to any stairway:
- Avoid spiral and curved stairs. These result in a stair tread with a reduced ‘going’ (or length) in parts of each tread. A narrow tread is a major cause of misjudging the steps. If curved stairs must be provided, the going should be not less than 200 millimetres.
- It has also been recommended that the wide range of going and riser combinations be reduced to a more consistent riser and going combination of approximately 178 millimetre riser height and 280 millimetre going.
- Providing a handrail on both sides of the stairs can be useful. Some 70 per cent of accidents have been found to occur within the top or bottom three steps of a stairway and extending the handrails over the landing at each end will help to provide extra stability:
- Handrails should be 30 to 50 millimetres in diameter, maintain a 50-millimetre clearance (minimum) from any side wall or obstruction and permit a 270-degree clearance around the profile of the handrail.
- If the stairway is greater than three metres in width, a handrail should be considered down the middle.
- It has been recommended that the accepted handrail height of 865 to 1,000 millimetres be increased to a 910 to 920-millimetre minimum height, as this has been shown to be the optimum height for the widest user demographic overseaas.
- A second handrail should be considered on each side, installed at a lower height to provide for a greater range of people, this should be between 665 to 750 millimetres.
- Handrails should achieve at least 30 per cent luminance contrast to the backing surface for ease of identification.
- Compliant profiles of stair treads are equally important. Common causes of accidents in stairs include catching the heel, the foot slipping off, overstepping the step completely, or under stepping. To address these issues, consider the following:
- In-filling all risers, as open risers can be visually confusing, and might cause tripping or a strobing effect.
- Reducing the number of steps in each stair flight to 16 is recommended.
- Making sure there is no overhang of each stair tread, as this could also cause tripping when ascending the stair.
- Installing a slip-resistant nosing strip that provides at least 30 per cent luminance contrast to the stair tread and a depth of between 50to 75 millimetres.
- Avoiding using multicoloured, abstract or confusing floor coverings.
- Install tactile indicators on the top and bottom landings to act as a sensory cue as you approach the stairway.
- Ensure a consistent slip-resistant rating throughout a stair, including the tactile indicators on landings, to improve usability and reduce slips and trips.
- The minimum illumination on stair should be 150 lux, with at least 200 lux on each landing.