Factors affecting the usability of stairs Dr Michael Wright 21st October 2002

Contents of presentation Current UK regulations Our research Our results and recommendations

What are the current UK requirements for stairs? There are two Building Regulations which cover stair design Part K: Stairs, ramps and guards Part M: Access and facilities for disabled people

Approved Document K Institutional and assembly stairs Maximum rise = 180 mm Minimum going = 280 mm 550 mm  2Rise + Going  700 mm Minimum Headroom = 2 m For maximum rise for stairs providing the means of access for disabled people reference should be made to Approved Document M

Going (mm) Rise (mm) Going plus twice rise = 700 mm Going plus twice rise = 550 mm

Approved Document K Institutional and assembly stairs - continued No minimum width recommended Maximum length of flight is 16 risers Level landings at top and bottom of every flight (at least as long as the narrowest part of the flight) Stairs narrower than 1 m should have at least 1 handrail, otherwise a handrail on both sides (mounted between 900 mm and 1000 mm from pitch line)

Approved Document K Institutional and assembly stairs - continued Flights and landings should be guarded at the sides if there are two or more risers If children under 5 years might use the stair the guarding should not be readily climbable, nor should a 100 mm sphere be able to pass through the guarding. The height of the guarding should be at least 900 mm.

What can be done to make stairs easier to use? The regulations in Part K were drawn up with an “average” user in mind. Part M deal with “disabled people” which means, according to the regulations, someone who has “(a) an impairment which limits their ability to walk or which requires them to use a wheelchair for mobility, or (b) impaired hearing or sight.”

Approved Document M External Non-Dwelling Stairs - disabled people Top landing has corduroy tactile surface, 400 mm from top nosing to 1200 mm from top nosing Nosings distinguishable through contrasting brightness Unobstructed widths of at least 1 m Rise between landings a maximum of 1.2 m Maximum rise = 150 mm Minimum going = 280 mm

Going (mm) Rise (mm)

Approved Document M External Non-Dwelling Stairs - continued Risers are not open A flight of 2 or more risers should have a suitable continuous handrail on both sides Handrail is at least 900 mm above the pitch line Each handrail should extend at least 300 mm beyond the first and last nosing Profile of handrail is suitable (shows a circular one, 45 mm to 50 mm diameter)

Approved Document M Internal Non-Dwelling Stairs - disabled people No requirement for provision of tactile surface Nosings distinguishable through contrasting brightness Unobstructed widths of at least 1 m Rise between landings a maximum of 1.8 m Maximum rise = 170 mm Minimum going = 250 mm Less generous due to more onerous design constraints

Going (mm) Rise (mm)

Approved Document M Internal Non-Dwelling Stairs - continued Risers are not open Same requirements for suitable handrail Exceptionally the provisions of the rise of a flight may be varied if particular storey heights or the need to gain access beneath an intermediate landing dictate, or the additional length of the stair has unreasonable effects on usable floor areas. Then use AD K

So, what is there left to do? Some groups have not had their needs addressed, and there are other features which are not dealt with in the Approved Documents, for example not all of the following groups are explicitly considered;  less able stair users:  elderly (over 75 years of age),  ambulant disabled,  visually impaired,  elderly visually impaired (over 70 years of age);  people of extreme sizes:  tall people (above 95 th percentile for height),  heavy adults (above 95 th percentile for weight),  small adults (below 5 th percentile for height),  children.

What was done? These groups were presented with 5 different stairs, they used them, and in focus groups we collected their opinions on every design feature they had experienced. These were compared with “average” subjects, those who fall within 15% of the mean weight and height of the adult population in the UK, one male group and one female group. This work was funded by the Office of the Deputy Prime Minister

Dimensions Rise Going Pitch Headroom

Going  Is perhaps the most influential of all stair dimensions  Previous research has shown that larger goings are preferred

Subjective questions I would feel safe having this stair in my home I had to pull myself up the stair using the handrail I hardly had to look at the steps as I came down the stair There was enough room to put my feet comfortably on each step I relied on the handrail to support me as I came down the stair I felt safe walking up the stair I would not like to negotiate this stair in the dark I had to turn my feet sideways to place them on each step I had to concentrate all the time when climbing down the stair I could hurry / rush down the stair if I had to While descending I had to walk with my body twisted I felt that there was not enough room for my feet It would have been easy to fall down the stair Its easy to mis-judge a step when climbing down I felt safe walking down the stair

Subjective responses Q4 mean rank Q6 mean rank Q10 mean rank Q15 mean rank Q15: I felt safe walking down the stair

No difference in opinions from 275 mm onwards Going (mm) Mean Rank Mean Rank Left Axis Q2 mean rank Q5 mean rank Q7 mean rank Q8 mean rank Q9 mean rank Q11 mean rank Q12 mean rank Q13 mean rank Q14 mean rank Right Axis Q1 mean rank Q3 mean rank Q4 mean rank Q6 mean rank Q10 mean rank Q15 mean rank Subjective responses

0% 10% 20% 30% 40% 50% 60% Going (mm) Percentage of shoe length 90th Percentile 10th Percentile Proportion of shoe overhang

Going  Is perhaps the most influential of all stair dimensions  Previous research has shown that larger goings are preferred  This preference was confirmed within this study

What goings were preferred? 298 mm250 mm220 mm300 mm250 mm

Going  Users found it difficult to consider going in isolation

What about rise and going combinations? 298 mm250 mm220 mm300 mm250 mm ? x 222 mm185 mm186 mm200 mm163 mm going rise x

Going (mm) Rise (mm)

Headroom 1948 mm down stand 2167 mm parallel x ?

Conclusions Larger goings are preferred, no smaller than 250 mm Going cannot be considered in isolation A rise of 200 mm is acceptable with the right going May need to limit pitch to about 37° Tall users are used to restricted headroom at 2000 mm Parallel soffits can feel claustrophobic if they extend too far along the flight.

Handrails

Purpose of handrails  Guidance - This is especially true for people who are visually impaired, who tend to use the handrail as a guide  Support - This is especially true for people who have difficulty walking, or are old, who can use the handrail to keep balanced or to pull themselves up when climbing  Stability - In the event of a fall or a wobble, a handrail can help stabilise the user and may help prevent a serious injury

Areas to be covered  Shape  Size  Continuity and gap  Overhang  Height  Number

Shape - pigs ear x

Shape - traditional ?

Shape - circular, oval, flat

Size 50 mm diameter 50  Beyond 95th percentile grip 46 mm  Difficult to get thumb around

Size 30 mm diameter  Beyond 5th percentile grip 32 mm  Cannot get fingers past supports 30

Size x x  5th to 95th percentile grip for UK adult population

Size - circular, oval, flat  May be better consider perimeter for other acceptable shapes  Perimeter should be between 100 mm and 150 mm

Continuity and gap  50 mm too small (50 mm to 60 mm recommended in BS8300)  100 mm too large  75 mm preferred  Should continue throughout flight

Overhang  Indicates start of flight in descent  Used to pull user up last step  Should be at least 300 mm At the top  Indicates end of flight in descent  Less necessary than at top  Could use alternative termination  Clothes might catch on open ends At the bottom

Height 900 mm mm preferred Children choose higher handrail

Number Two handrails preferred Provide choice in descent 800 mm to 1000 mm apart Some felt unsafe with no handrails Some need handrail to climb

Conclusions Two handrails 800 mm mm apart 900 mm above pitch line Handrails should extend beyond flight, especially at the top 75 mm wall gap Diameter between 32 mm and 46 mm or Perimeter between 100 mm and 150 mm Circular oval, and flat shapes work best

Other design features Landings (for resting) Winders Open risers Overhanging nosings Hard Surfaces Designation Contrasting nosings

Landings Visually impaired users did not like the landings, since the hardest part of the stair to negotiate was the transition to or from the level and this had to be performed more than once with a landing.

Landings Landings dictate where a rest can occur The height of the landing did not seem to be an issue When comparing the same overall length of stair, a larger going of 300 mm was preferred over a 900 mm landing in the flight

Winders Difficult to maintain constant going between steps, which may lead to confusion Difficult for most people to negotiate, especially those with poor vision

Open and partial risers, overhanging nosings Full PartialFullOpen Open risers disliked by many users, impossible for some users Traditional nosings can be just as bad xxx

Hard surfaces Hard surfaces make noises, which is disconcerting for some users Can cause more serious injuries on collisions xxx CarpetMetalTileLinoleumWood

Designation Colour and shade Projecting handrail Tactile Most users did not notice the designation without prompting The handrail designation was considered to be the best approach

Contrasting nosings Did help indicate the nosings in descent (painting is sufficient) No one wanted them in their home Avoid busy or patterned carpet Provide good lighting, preferably from two sources

Conclusions Larger goings preferred over landings Winders to be avoided unless adequate handrails supplied Open risers should be avoided Traditional nosings could cause problems for some users Avoid hard surfaces Extended handrails are the preferred method of designation Provide adequate lighting Avoid busy or patterned carpets