Landfill diversion is working – but waste is still rising

For two decades the construction industry has chased a single waste target: keep material out of landfill. By that measure, the job is very nearly done.

New analysis by SmartWaste of almost 4,800 UK projects, worth £34bn and completed between 2016 and 2025, shows that the typical project now diverts 99.5% of its waste from landfill. A decade ago the figure was already high. Today, sending waste to landfill is the exception. It is an industry success, built on better segregation, stronger recovery markets and tighter targets.

But diversion measures only where waste ends up. It says nothing about how much we create in the first place. On that question, the data is less reassuring.

Over the same decade, the amount of construction waste generated per 100m² of floor area has risen by more than 10%, to 6.6 tonnes. On new build projects the picture is worse: 9.0 tonnes per 100m², some 36% above the average. New build residential is the most material-hungry of all at 11.3 tonnes, against 6.8 for commercial work. Measured by floor area, we are building more wastefully than we were ten years ago, even as we divert more of the result.

The figures expose an awkward gap. The industry has become very good at managing waste once it exists, and barely better at producing less of it.

The reason diversion has plateaued is simple: it has little room for further improvement. When a typical project already diverts more than 99%, what else is there to send to landfill? The next significant phase of improvement will not be found in better skips or smarter sorting. It has to come earlier, either by further improving circularity and reuse or, as our data suggests, before a single delivery arrives to site.

That is an uncomfortable conclusion for an industry whose main waste tool, the Site Waste Management Plan, is built around managing material after it has been specified and ordered. By the time a plan is written, the waste has largely been designed in. Reducing it meaningfully means moving the decision upstream, into design, specification and procurement, where the quantity of material is determined.

The same dataset offers a way forward. Where the industry has chosen to measure something, it has tended to improve it. Carbon intensity from site energy use has fallen by around a quarter over the decade. Water use relative to project value is down by almost as much. Put a number on something and it starts to move. Waste intensity has not yet had that treatment.

The implication is straightforward. Diversion was the right goal for the last decade, and it has been met. The harder work now is cutting the waste we generate in the first place, designing it out rather than diverting it after the fact. In practice that means setting targets on tonnes of waste per square metre, not only on the share kept from landfill, and giving designers the data that site teams have used for years.

For ten years the industry successfully segregated waste and measured where it went. The next ten will be defined by how much it stops creating.

Find out more about SmartWaste.

This article first appeared in Construction News.