Reduce waste to improve quality

Half of all the waste produced in Scotland comes from the construction sector, Nick Ribbons from Zero Waste Scotland told delegates at the joint GIRI/CQIC launch event in Edinburgh in February. He argued that getting a grip on waste is essential to improving quality in the sector, because better quality extends the life of a building, reduces the demand for virgin materials and drives down waste.

Zero Waste Scotland works across sectors to create a society where resources are valued and nothing is wasted. Its mission for construction applies this to the whole life of the building, from concept to deconstruction, to embed a circular economy approach within the sector – and quality is a critical element of this.

Nick discussed several approaches that can improve quality by reducing waste. “The passive house approach, for example, can drive up quality across the build because when the contractor is focused on detail they tend to apply this focus across the board. Another is off-site construction, where materials are specified and cut in a controlled environment with little waste, and quality assurance can happen before materials leave the factory.”

He also highlighted design for recovery, pointing out that by designing buildings in such a way that the different elements are accessible for when they need to replaced at the end of their life, it is possible to minimise both waste creation and disruption for occupants, which also improves the quality of use.

Nick said that Zero Waste Scotland advocates the fabric-first approach to material quality. “This requires consideration of which fabrics may be problematic in the future. We’ve seen issues around cladding, but it also applies to things such as insulation. It’s about specifying the quality of materials appropriate to the use. One common objection we hear is that these materials simply aren’t available at the volume people are building, but this is changing.”

Zero Waste Scotland has provided nearly £2 million in grants to IndiNature, a natural fibre solutions company, and Kenoteq, which makes bricks with a tenth of the embodied carbon of traditional bricks and higher performance. “We are also looking into steel reuse. Steel is highly recyclable but reuse and recycling in higher value use doesn’t happen – only about 1% of steel is reused in this way.”

However, the link between quality and waste is most immediate at site level, where so much material waste is generated but so little data is available to analyse this. To fill this gap, Zero Waste Scotland has just launched a quality tool to help contractors understand what is going into skips on site. “It sounds basic, but to be able to drive up quality you need to understand the link between the different aspects of the waste you create on site. The launch of the tool follows the recent publication of our circularity gap report that shows that 98% of our material use comes from virgin resources, and that 50% of all Scotland’s waste comes from the construction sector.”

The tool analyses what goes into skips, where it comes from, and why, presenting the information in a simple dashboard that not only highlights the real cost of poor quality but can also improve target setting and feed into procurement and contractor decision-making.

“The really interesting outputs are waste by volume and condition of waste, which tells us the potential recyclability of the waste. Often these are newly procured materials and if they are only fit for landfill, we know there have been poor quality behaviours on site. Then we have outputs by source, and this is of interest to everyone. Where is the waste coming from? For example, unrecovered packaging, stripping out previous work, wrongly specified, damaged, and cutting waste. Again, damaged materials are down to behaviour.”

However, Nick pointed out that this data is of no value unless it is used to inform the decisions of site managers, quantity surveyors, designers, and workers on site. “This is where collaboration needs to happen. Do we know the ingredients for successful collaboration and can we teach that? Just getting everyone in the room is not enough. There needs to be commitment, because waste reduction drives higher quality and vice versa – if you focus on quality you get very little waste.”