Clear opening widths, costs and structural considerations
Standard UK internal door clear openings are 726–762mm (a 762mm doorset gives approximately 717mm clear opening with the door open 90°). Wheelchair access requires a minimum 800mm clear opening (optimum 900mm) — this requires a doorset width of at least 870mm. Widening a doorway in a non-load-bearing stud partition wall is a straightforward 1-day operation: the existing frame is removed, the opening is widened by cutting back the stud frame, a new wider frame and door are fitted. Cost: £500–£900 per doorway including materials and labour. Widening a doorway in a load-bearing brick or block wall (more common in London Victorian terrace internal walls) requires the opening to be temporarily propped, a new structural lintel installed above the wider opening, and the brickwork made good above the lintel. A structural engineer specification is recommended for load-bearing lintels in older London properties where the wall construction is not clearly known — engineer fees £150–£300, lintel specification typically a steel padstone arrangement or Catnic box beam. Cost: £900–£1,500 for a straightforward load-bearing single brick wall; £1,200–£1,800 for double brick walls or where unexpectedly complex joist bearing is encountered. In London Victorian and Edwardian terraces, many internal walls are timber-studded with brick-veneer outer faces — these are often not load-bearing, but site investigation is required before assuming. The OT specification typically targets: front door (800mm clear), living room door (800mm clear), kitchen door (800mm clear), bedroom door (800mm clear), and bathroom door (800mm clear). Depending on existing openings, some doors may already meet the 800mm standard — a measured survey of all doorways is the first step.
Door hardware, hinges, threshold strips and DFG
Wheelchair-accessible doors require appropriate hardware in addition to the wider opening. Lever door handles rather than knobs are Part M-compliant and essential for limited-grip users — Hoppe, RIBA-approved lever handle sets cost £25–£80 per door. Ironmongery should contrast visually with the door leaf for visually impaired users (Building Regulations Approved Document M recommendation). Hinges: standard 75mm butt hinges allow the door to open to approximately 95° — for maximum clear opening, wider-throw hinges (offset pivot hinges or concealed Soss hinges) allow the door to fold flush against the adjacent wall, increasing effective clear opening by 80–100mm. This is a cost-effective way to gain wheelchair clearance without widening the opening: installing offset pivot hinges costs £80–£150 per door and increases clear opening from 726mm to approximately 810mm without structural work. Threshold strips: ensure all doorway thresholds are level or ramped (maximum 10mm upstand, tapered edge). Any threshold strip over 10mm height is a trip and wheelchair obstruction. DFG funding: doorway widening is a standard DFG-funded adaptation. Typical DFG-procured costs are £300–£800 per doorway depending on wall type, through competitive council contractor tendering. Multiple doorways widened in a single programme (2–4 doorways) reduces unit cost through mobilisation efficiency. The OT specification identifies all doorways requiring widening across the property — a whole-house doorway audit is part of the DFG assessment process.
