Reducing Plastic Waste in Every Stage of Construction

As Christmas approaches, many construction sites will be busy finishing tasks and putting things away until work restarts in the New Year. Christmas and construction generate a lot of waste through packaging, discarded or unwanted materials, “over-ordering”, and producing complex waste streams (many different material types). However, as the team at the Environmental Innovation Centre (EIC) explains, we can better manage our waste by considering the different stages of construction (and Christmas).

On a construction site, many different types of plastics are generated, some of which can be reused or recycled, and some which cannot. We recommend targeting the big streams — soft plastics, pipes, and polystyrene. If you are generating waste that is easy to sort with a clear reuse or recycling option, we recommend you collect it — eg plastic cable reels usually made of polypropylene (PP) can be re-spooled and/or recycled.

 The Planning and Design Stage

Just like holiday shopping, over-ordering materials and poor planning in construction can lead to excess materials being ordered, which can end up in the bin. Aim to order only as much material as you need to avoid generating excess. Choose materials with reuse or recycling options; for example, CLEVA POD® (made of recycled PP) can be separated from concrete foundations and reused or recycled at the end-of-life. In contrast, polystyrene insulation is more challenging to recycle at end-of-life because it must be uncontaminated, which is often difficult as it may be bonded to concrete, soil, or other materials.

Foundation Stage

Depending on your site, the foundation stage tends to generate relatively little plastic waste (Figure 1). Polystyrene insulation offcuts will be a large stream if you are using it in your building (Figure 2). You may also have some DPM offcuts and soft plastic packaging (these can often be recycled together). For most sites, a couple of well-placed bins should be enough during this phase.

Figure 1 – Plastic waste generation over three construction stages

Figure 2 – Plastic waste types generated over each construction stage (based on four case study sites)

Structure and Framework Stage

Waste generation tends to increase at this stage, particularly soft plastics and pipes - only a small amount of polystyrene (Figure 1 & 2). If your site is using building paper, there can be large amounts of waste produced from the backing product over this stage and the next. This backing paper has silicon in it, so cannot be recycled easily.

We also recommend setting up a GIB bag for plasterboard offcuts which will be produced at this stage, as well as designated spaces for timber and metals. These are relatively easy to identify and sorting them early prevents clutter and mixed waste.

Interior/Exterior Fitout and Fittings

This final stage is just like the weeks leading up to Christmas Day. You’re wrapping presents, making food, putting up decorations, cleaning the house! All of these are a part of Christmas, but they can generate waste. At this stage of construction, plastic waste generation is usually at its peak.

Again, soft plastics and pipes become prominent plastic waste streams (Figure 2). If you are using shrink wrap, that will likely be one of the biggest waste streams in this stage – check out GoodWrap Recycling for their holistic shrink wrap stewardship scheme.

Christmas Eve – nearing project completion

As with Christmas, the lead-up to the big day (handover) can be hectic with last-minute tasks and touch-ups being done.  Staff get busier and start to neglect waste management, tossing everything into general bins rather than sorting carefully as they did a few months earlier.

Plan for this last push by designating a waste leader to oversee sorting or simplifying to one or two manageable waste streams.

Staying organized here will make a big difference, and doing something small is better than doing nothing at all. 

If you need any help with where to find recyclers, buy bags or source free printable signs, check out  WasteHub at www.wastehub.co.nz

Post Construction

The big day is finally here! The waste has all been cleared away and everything is well organised, neat and ready to go. Usually, the skip bin is a mix of different waste materials; however, if you have managed your waste well, it can be reserved for only non-recyclable, non-reusable waste.

By integrating these waste management steps into your construction process, you can close out the year on a sustainable note—ready to tackle next year’s projects with a fresh, waste-conscious approach. 

If you have any questions for the team that you would like answered in this column, please contact us.