Adaptable housing is a subset of the open building philosophy (1) which focuses on designing housing so it is flexible enough to accommodate future special needs users. This ties into the concept of visitable housing, developed by Selwyn Goldsmith. Together they recognise that many of us will be less than fully able (physically, sensorily, intellectually) at sometime in our lives – through birth, disease, accident or age. Accordingly, all housing (and particularly social housing) should be designed with this need for flexibility in mind, especially given the increasing number of disabled people living in the community, and the expanding aged population (71% more people over age 65 in 2040 than in 1998).
This concept is implemented through the Lifetime Homes project developed in 1991 by the Joseph Rowntree Foundation Lifetime Homes Group, and through Housing Corporation Scheme Development Standards. It is also implemented overseas, for example in the USA (Fair Housing Amendments Act 1988), the Netherlands, Scandinavia and Australia (via AS 4299:1995).
Following is a survey of key adaptability requirements, mostly the tighter of the Lifetime Homes standards and ‘essential’ features from AS 4299. AS 4299 is much more comprehensive, and is generally tighter, but assumes single-storey dwellings. Given the serious safety problems with steps and stairs (2), and the related problems they create for special needs access, this is sensible.
Access to the building should be via short continuous accessible travel paths from the street frontage and vehicle parking to the dwelling entry. Car parking bays should be at least 6 x 3.8 m. For estates, next to the street entry, locate lockable letterboxes centrally.
Provide an accessible path to the clothes line from the laundry. Ensure public and common areas of the site and building are accessible to and usable by handicapped persons.
Entrances should be covered, illuminated, accessible, and level (maximum 1:40 slope), with a 15 mm maximum threshold. Provide a landing for wheelchair manoeuvrability.
General fabric and services
Drawings showing the housing unit in pre-adaptation and post-adaptation stages should be given to the contractor and other interested parties.
At least one storey in a block of flats should be accessible without steps. Within the dwelling, avoid steps, and allow only minimal level changes. If more than one floor is unavoidable, provide for a stair lift and a through-the-floor lift.
Provide for wheelchair door approaches. Corridors should provide accessible routes into and through the dwelling, with a minimum clear width of 1000 mm.
Entrance doors should have a minimum clear width of 850 mm, and suitable handles and hardware. Internal doors should have 820 mm minimum clear width. Door hardware should be 900-1100 mm above floor, and operable with one hand.
Wheelchair users should be able to access some shelves and cupboards, and operate electrical and environmental controls, taps, and windows.
Provide slip-resistant floors to the kitchen, shower, toilet and laundry.
Walls to be demolished as part of planned adaptation should be non-loadbearing, and free of electrical and plumbing services.
Living, dining and bed rooms
Locate the living room at entrance level. Living room windows should begin within 800 mm of floor level. Provide an illumination level of at least 300 lux to the living and dining room, and locate the telephone next to the power outlet.
The main bedroom should be big enough for a queen size bed, wardrobe and wheelchair circulation space. Provide a convenient bed space at the entrance level of dwellings with 2 or more storeys.
Pre-adaptation, provide for a circulation space 2250 mm minimum diameter in the living and dining room.
The kitchen should have manoeuvring space for a wheelchair, with at least 1550 mm clear between benches. Provide for wheelchair circulation at doors.
The kitchen layout should have the refrigerator next to a work surface, the cooktop next to a work surface at the same height (minimum 800 mm long), and the oven next to an adjustable (between 750-850 mm high) or replaceable work surface at least 800 mm long.
The kitchen sink should be adjustable between 750-850 mm high, or replaceable, with a bowl no more than 150 mm deep. The kitchen tap set should be capstan or lever handles or lever mixer, and located within 300 mm of the front of the sink.
Kitchen cooktops should have front or side controls and raised cross bars, and an isolating switch.
Kitchen power outlets should be suitable for disabled users, with at least one outlet within 300 mm of the front of the work surface. The outlet for the refrigerator should be easily reached when the refrigerator is in place. The laundry power outlet should be double.
Bathroom, shower, toilet
The bathroom should have manoeuvring space for a wheelchair, with wheelchair access to fixtures. Bathroom tap sets should be capstan or lever handle with a single outlet and a thermostatic mixing valve.
The shower recess should be 1160 x 1100 mm minimum, hobless and waterproof, with a fall to waste and a recessed soap holder. Shower taps should be easily reached from the access side of the shower door.
Locate toilet pans the correct distance from the walls – this depends on the configuration. Locate a toilet in the entrance storey or principal storey of the dwelling. This should be visitable or accessible by disabled users in dwellings of 3 or more bedrooms.
Pre-adaptation, in bathrooms, provide for a washbasin with wheelchair clearances. Provide for a hoist from a main bedroom to a bathroom. In shower and toilet walls, provide reinforcement between 300-1500 mm above floor, so that showers and toilets have provision for grab rails. In the shower, provide for an adjustable, detachable, hand-held shower rose, mounted on slider grab-rail or fixed hook. In the entrance storey toilet, provide drainage for a shower, and provide for manoeuvring space for a wheelchair.
Pre-adaptation, provide for circulation of 1550 mm minimum depth in front of or beside appliances, and for an automatic washing machine. The laundry should be accessible to wheelchair users after adaptation, with wheelchair circulation at doors.
These requirements transcend those in Part M, which simply requires ‘reasonable provision’ to be made for access to and use of the building by disabled people, and ‘reasonable provision’ of sanitary conveniences in the entrance storey or principal storey of the dwelling. The Approved Document goes into more detail, of course, and is set to be replaced by an even more substantial document (based on BS 8300), in 2004. Nevertheless it is likely that adaptable housing provisions of the sort outlined in this article will continue to exceed statutory minima.
(1) The open building (or agile architecture) philosophy entails designing for flexibility (function stays the same, but users or processes change) and for adaptive reuse (function changes) of all building types (see activities of CIB W104 Open building implementation). This concept is widely implemented in the Netherlands and Japan. It is an optional extra in the BRE’s EcoHomes environmental rating system.
(2) In the UK over 1996-98, over-65s suffered 2,656 fatal falls on stairs or steps in the home, 61,842 serious injuries, and 104,238 minor injuries requiring a hospital visit. Under-65s are not immune to falls on steps or stairs – 71% of serious injuries were in this age group, and 35% of deaths.