Demolition Waste Calculator

Multiply the room length by width by height to get the gross volume in cubic metres. Then apply a fill percentage — typically 60-80% for a full strip-out and 20-40% for selective demolition. The calculator converts volume to weight using material density factors per WRAP guidelines.

It depends on the mix. A light, well-segregated mixed construction stream (offcuts, packaging, some plasterboard and timber) is only about 0.5 t/m³ — the mean loose bulk density for mixed C&D waste in the WRAP-cited big-data study (Lu et al. 2021) is around 0.53 t/m³, and skip operators quote roughly 0.3–0.5 t/m³ for general mixed waste. Demolition arisings are far heavier because they are dominated by brick and concrete rubble: brick/masonry is around 1.8 t/m³ and concrete around 2.4 t/m³, with timber much lighter at about 0.6 t/m³. This tool therefore defaults rubble-heavy 'mixed demolition waste' to a conservative 1.5 t/m³ working value — closer to the masonry end so you do not under-order skips. If your waste is light and segregated, drop the material type to match, or lower your expectation toward 0.5 t/m³.

Full demolition arisings are roughly 1.3–1.6 tonnes per m² of ground-floor (footprint) area — not per m² of total floor area summed over every storey. A typical 3-bed semi has a ground-floor footprint of about 45 m², so a full two-storey shell yields around 45 × 1.3 ≈ 59 to 45 × 1.6 ≈ 72 tonnes; an above-ground strip-out is much less. As a worked example, 60 tonnes in 8-yard maxi skips (rated ~5 tonnes each in this tool) is about 12 skips (60 ÷ 5). For larger demolitions a grab lorry is usually more economical, carrying ~12 tonnes (6-wheeler) or ~16 tonnes (8-wheeler) per load. Always pin the figure to your own scope and measured volumes.

The UK achieves around 90% recycling rates for non-hazardous construction and demolition waste, one of the highest in Europe. Concrete and brick can be crushed for aggregate, timber can be chipped, and metals are highly recyclable. Plasterboard must be recycled separately due to gypsum content.

For larger quantities a grab lorry is usually more cost-effective than multiple skips. A 6-wheel grab (GVW 26 t) carries ~12 tonnes per visit and an 8-wheel grab (GVW 32 t) ~16 tonnes, and neither needs a skip permit. However, the lorry needs clear access within reach of its hydraulic arm — typically around 5–6 m for a 6-wheeler and up to ~10 m for an 8-wheeler.