Demolition is high-risk, high-cost work where an estimate lives or dies on the items that do not appear on a drawing. Accurate demolition estimating starts before the machines arrive: an asbestos survey, a structural assessment of what is holding the building up and in what order it can safely come down, and the temporary works and protection needed for adjacent properties and party walls. Miss any of these and the price is wrong before you begin.
From there the estimate breaks into clear packages. Soft strip — removing fixtures, finishes and services — is usually priced by floor area. Structural demolition is priced by volume or as a lump sum for the building, with the right plant: a 360 excavator with a breaker or muncher, high-reach for taller structures, and crushing plant where material is processed on site. Asbestos and other hazardous materials must be removed by a licensed contractor and priced as their own allowance, never buried in a rate. And disposal is often the single biggest cost — muck-away and demolition waste priced by the tonne and by the lorry load, with recycling and material recovery factored in where possible.
How ConstructQS handles demolition
ConstructQS includes a demolition and site-clearance project preset that sets sensible preliminaries, overheads, contingency and profit for the risk demolition carries, plus rate-book items for demolition operatives, breaker/muncher plant, soft strip, structural demolition, licensed asbestos removal and disposal. Your own rates take priority, every price shows its source, and the AI QS assistant flags the classic demolition omissions — a missing asbestos allowance, no disposal rate against the demolition quantity, or no temporary-works and protection allowance — before you tender.