How Much Construction Waste Will I Generate?
Quick Answer
Typical extension: 5–10m³ waste. Segregate for recycling.
Based on: Single-storey rear extension including excavation spoil, packaging, and off-cuts
Waste by Project Type
- Bathroom refit: 1–2m³ (tiles, sanitaryware, plasterboard)
- Kitchen refit: 2–4m³ (units, worktops, flooring, plaster)
- Single-storey extension: 5–10m³
- Loft conversion: 3–6m³
- New build house: 15–25m³
- Full house renovation: 10–20m³
Waste Breakdown for a Typical Extension
- Excavation spoil (earth): 3–5m³
- Brick/block off-cuts: 0.5–1m³
- Timber off-cuts: 0.5–1m³
- Plasterboard waste: 0.3–0.5m³
- Packaging (plastic, cardboard): 0.5–1m³
- Mixed rubble: 0.5–1m³
Reducing Waste Costs
- Segregate materials: Separate skips for inert, timber, and mixed waste reduce disposal costs
- Reuse excavation spoil: Use clean earth for garden landscaping
- Order accurately: Use calculators to avoid over-ordering materials
- Recycle plasterboard separately: Cannot go to landfill (legal requirement)
Skip Sizes for Construction
- Bathroom/kitchen refit: Midi skip (4yd³) ~£150–250
- Extension: Large skip (8yd³) ~£250–400, or two builder’s skips
- Major build: Roll-on/roll-off (20–40yd³) from £500
Legal Requirements
Under the Site Waste Management Plans guidance, all construction projects should plan for waste minimisation. Plasterboard must be recycled separately and cannot be sent to landfill with other waste.
Last updated: April 2026