In 40 seconds
An accessible bathroom in the UK is usually built around one of a few changes. A walk-in bath supplied and fitted typically costs around £2,500–£6,000, while a walk-in shower for an elderly or disabled person commonly runs £5,000–£8,500 for a level-access conversion. A full mobility bathroom conversion is often around £4,000–£8,000, and a wet room adapted for a disabled user typically £6,000–£10,000. Much of this can be funded: the Disabled Facilities Grant provides up to £30,000 in England following an occupational therapy assessment, and adaptations for a disabled person are usually zero-rated for VAT. The honest answer is always a range, because it depends on the person's needs, the room and the works involved.
Most accessible-bathroom information online is published by companies that sell the work, so the numbers can be optimistic and the funding routes glossed over. The pages below give careful, sourced cost ranges, explain how the Disabled Facilities Grant and occupational therapy assessment actually work, and set out the VAT relief — so you can plan calmly before taking any quote.