Measure the opening that is actually available
The relevant passage is the space available when the door is open in its normal position. The leaf, stops, hinges and hardware can affect that space. As a simple illustration, a door sold with a nominal width is not a promise of an identical clear opening after installation.
Include the approach and exit
A straight approach differs from turning through a door from a narrow hallway. The space needed to operate the handle and hold the door matters too. Measure the surrounding area rather than recording only the frame.
Use the equipment that will travel through it
Everyday wheelchairs, shower chairs and walkers can have different dimensions and operating needs. Consider hand clearance, assistance and turning as well as the equipment width. Ask an occupational therapist to establish the relevant functional requirements.
Keep dimensions separate from compliance claims
An existing private home, new building work and a specifically funded or certified design can have different requirements. The responsible designer or certifier should identify what applies. This article does not supply a universal construction minimum or certify a layout.
Compare widening with other door arrangements
A different swing or suitable sliding arrangement may help in some homes. Neither is automatically the right answer. Check privacy, emergency access, usable wall space and whether the user can operate the door.
Investigate the wall before committing
Widening may affect load bearing structure, wiring, plumbing and nearby fittings. The quote should cover the opening, frame, door, hardware and reinstatement. Ask what remains provisional until the wall is investigated.
Bring a complete brief to the assessment
Prepare a photo of the approach, the room beyond and the door in its open position. Include equipment dimensions and any existing recommendation. Do not share private medical details through the initial form.