We want to change that.
Our recent Construction Masterclass brought together many of those leading positive change in the sector.
It found the sector needs to:
- Recognise that reducing waste reduces greenhouse gas emissions
It may seem obvious, but it’s not widely understood. Reducing construction waste directly reduces carbon emissions. This is particularly true when we take the ‘embodied’ carbon emissions fully into account. These are the emissions associated with the materials used throughout the life of the building. To reduce those emissions, we must reduce the associated energy use. We can do that by reducing the new materials in a construction project. That means reducing over-ordering. It means increasing reuse and using recycled materials wherever possible.
- Work together on this
This is a systemic challenge. It needs everyone. Architects, developers, material suppliers, contractors, builders, consultants, end of life solution providers and regulators. This requires collaboration across organisations throughout the value chain. Regan Burke from Civil Share summarised it well in his call to action “collaborate, get together and share”.
- Design in the changes
It's often said that “80% of the environmental impacts of products are determined in design”. If we want a low carbon circular economy, we have to design for it. This means designing buildings with low carbon materials. We need to assess the full life cycles of buildings and their materials. They must be energy efficient, long lasting and adaptable. They need to be designed to be reused and/or deconstructed so the individual materials can be reused.
- Do more building off site
A study from the UK suggests 13% of building materials delivered to site go straight to landfill without being used! Scott Fisher at OffsiteNZ was among those pointing to the benefits of off site building construction. Reduced costs. More accurate timing. Less site disruption. Safer working conditions. Less waste.
- Procurement is a powerful driver of change
Particularly the spending power of large organisations. Kāinga Ora now focuses on relocation and deconstruction rather than demolition. It's achieved an 87% diversion rate from landfill this financial year. That’s the equivalent of about 20,000 tonnes of material, nearly 4,500 homes’ worth of rubbish. Its value has been estimated at around $140 million.
- Get the people working on the ground to talk about it
Construction and demolition sites are dynamic environments. There's not always clear guidance or easy processes and protocols. Time pressures can lead to wasteful mistakes. Junk Run described preparing to remove and reuse a large consignment of glass office dividers. But another contractor was unaware of this, and smashed them all.
- Know the life cycle of its materials
Modern technology could enable ‘material passports’ to track items throughout their lives. This could help identify on-use after demolition. It can provide data on end-of-life destinations. The concept has been around for more than a decade, but has not gone mainstream. New Zealand’s Heavy Engineering Research Association is developing this for structural steel. It could be the first of its kind in Australasian construction. Half our attendees took part in a hackathon session looking at further options on this.
- Have the existing options at its fingertips
Older homes may not have been designed with a low carbon circular economy in mind. But firms in Aotearoa New Zealand can maximise their deconstruction value. For example, Levala Deconstruction is a finalist in this year’s SBN Awards Going Circular category. It achieves more than 80% diversion of materials from homes. It sorts and grades materials on site. It remills native timber. Pine materials are donated to charities. Roofing, plasterboard and joinery are reused and recycled.
- Invest in programmes to tackle the scale of the challenge and release its commercial potential
We asked attendees what they needed to scale up the transition to a low carbon circular construction sector. We received 137 industry needs. They covered everything from design, procurement, materials, production, end-of-life solutions and government action. We’ll continue to work with the sector to meet them.
What happens next?
Working with Auckland Council and the Ministry for the Environment, SBN will be creating and promoting case studies of successful circular economy approaches to waste and carbon in the sector.
SBN and Spaceworks will help coordinate the next stages of material passport development with interested industry stakeholders.
Keen to get involved? Reach out to james@sustainable.org.nz.
And we’ll continue to build connections across the industry on this and promote knowledge sharing in ongoing resources and events. Look out for details!
Thanks to Auckland Council, thinkstep-anz, Unitec Environmental Solutions Research Centre, Ministry for the Environment and Mitre 10 for partnering with us to deliver the Building out Waste and Carbon 2022 Masterclass.
