In 40 seconds
Demolishing a typical UK house usually costs roughly £6,000–£15,000+, often landing around £13,500 for a medium-sized property before extras, which on a per-area basis works out at roughly £40–£115 per square metre. Knocking down a single garage is far smaller, commonly £400–£1,500+ depending on size, materials and whether the concrete base comes up too. Before any teardown you normally have to give the local authority a Section 80 demolition notice under the Building Act 1984 (usually about six weeks' notice), and the Control of Asbestos Regulations 2012 require a demolition asbestos survey first so any asbestos is removed safely. The honest answer is always a range, because it depends on the building's size, materials, access and what has to be cleared away.
Most demolition guidance is published by firms doing the work, so the numbers tend to be optimistic and the legal steps glossed over. The pages below give honest cost ranges for houses, garages and outbuildings, explain the Section 80 notice and when planning permission applies, and set out the asbestos rules — before you take a single quote.