Precycle: sorting building waste before it gets contaminated
A South Australian circular economy case study Rawtec worked on. 2019.
Summary published
A skip bin on a building site collects everything, which means it recycles almost nothing. Business as usual on a residential build diverts about 10% from landfill.
Precycle changed the timing rather than the sorting. Materials get collected at set stages during construction, while they are still clean and separated, before the next trade contaminates them.
Landfill diversion went from 10% to 76%.
Landfill diversion, against 10% business as usual
Skip bins per house
Waste volume per house
CO2 avoided per site
What the trial showed
Fewer bins, less volume, more recovered
Skip bins per house fell from 3.8 to 1.1 and waste volume from 15 to 4.5 cubic metres. Landfill diversion rose from 10% to 76%. The service runs across six stages with pick-up on demand within 48 hours, and material is checked both at collection and at unloading.
The environmental numbers per site
1.4 tonnes of CO2 avoided, 19.7 gigajoules of energy saved and 4.1 kilolitres of water saved. Across ten houses that is roughly the annual emissions of 3.1 cars and the annual electricity of 3.8 households.
It costs less than the bins it replaces
The model works because multiple skip bin removals cost more than staged collection. Site safety improves, illegal dumping drops, and the material is worth something because it is clean.
The market is 8,000 to 12,000 homes a year
South Australia builds between 8,000 and 12,000 homes annually. A typical residential project runs 12 to 18 weeks, which is what makes staged collection practical.
Rossdale Homes was the trial partner
The builder reported environmental benefits plus better site amenity and material management, which is the part that actually persuades other builders.
What it depends on
The model only works if recycling outlets will take clean, sorted streams. Contamination is what kills construction recycling, and this is a scheme designed entirely around avoiding it.
One bin for everything is easier. Staged collection needs the builder to prioritise the cost saving over the convenience.
The service started with a 150 tonne a year limit, later removed. The case study suggests expanding across the South Australian construction sector and setting up a resource bank for reusable materials.
Related reports
Other pilots and case studies.
The full case study covers the six collection stages.
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