Universal design

Universal design means designing a building for the full range of people from the start, instead of designing for an imagined average user and bolting on a ramp or a lift afterwards. The architect Ronald Mace championed the term, and it was later set out as seven principles: equitable use, flexibility, simple and intuitive use, perceptible information, tolerance for error, low physical effort, and appropriate size and space.

How it differs from accessibility

Accessibility usually means meeting the minimum requirements written into codes. Universal design goes for not separating people at all: if the main entrance has no steps, nobody needs a separate accessible entrance round the side. The parent with a pushchair, the traveller with a suitcase, the teenager with a broken arm and the elderly neighbour all use the same door.

What it changes in the plan

• Level thresholds and flat, slip-resistant floors
• Corridors and bathrooms wide enough for a wheelchair to turn
• Lever handles and switches and sockets at reachable heights
• Wayfinding that reads through colour and texture contrast

Decided at the sketch stage, these choices are almost invisible and cost little. Added later, they are expensive and often spoil the architecture. Exact dimensions and obligations are set by the relevant regulations and standards in each country.