The Ministry for the Environment predicts C&D waste may represent up to:
- 50 per cent of all waste generated in New Zealand;
- 20 per cent of all waste going to landfill, and;
- 80 per cent of all waste going to clean-fill.
C&D waste is a complex waste stream, made up of a wide variety of materials including concrete, plasterboard, wood, steel, brick and glass. However, managed properly, C&D waste can be reduced, re-used and recovered, dramatically reducing the amount thrown away.
One recent project to prove this theory correct is the eco-classroom ‘The Living Room’ built at Hukanui School, with much of the credit being given to the creative thinking of the primary-aged school students.
The following case study tells the story of a student-led, environmental education initiative to plan, design and build an eco-classroom at Hukanui Primary School in Chartwell. It is the first project of its type in New Zealand, and it has an ambitious waste minimising target.
Hukanui School's eco-classroom building site The Living Room Project
- built to make the most of natural sunlight and heat
- rainwater collection tanks
- natural ventilation – large opening doors, louvers and skylights
- double-glazed windows to prevent heat loss in winter and remain cool in summer
- extra thick concrete floors to absorb energy during the day and release it at night
- untreated timber sourced from sustainable plantations (macrocarpa, poplar)
- environmentally friendly insulation used from wool, wine bottles and recycled plastic
- biodiversity friendly, with plans that have minimal impact on the site and maximum care for the
- surrounding habitats during the building process
- a sustainable outside, including native tree planting, nursery, vegetable garden,
- beehives, bird feeders and a new location for existing recycling systems.
Hukanui School Eco Classroom Waste Management Plan
Ordering the right amount of product to prevent oversupply
Reducing inefficient resource use
Identifying a second-use for materials classed as ‘waste’
A change of mentality from having a single skip destined for landfill
- Timber: Waste was avoided by sorting and stacking timber on site. Any timber products were re-used or sorted for classroom heating. Saw dust was collected and used for composting.
- Metals: Waste metals were collected for recycling. Examples include steel off cuts, nails, roofing, iron, screws, reinforcing steel and electrical cables.
- Organics: Food scraps were collected for the school wormery.
- Packaging: Cardboard and paper were stacked for recycling.
- Polystyrene: Polystyrene products were collected and recycled by an Auckland based collector.
- Concrete: Old dug up concrete was reused and recycled.
The waste streams were broken down and reported on in the following areas:
- Clay / Soil / Sawdust
- Organic Waste
- Landfill ‘bucket’
- Packaging plastic
- Metal – Steel, copper and iron
Ingredients for success
- What alternative use is there for the demolition waste? Can it be recycled/re-used?
- How can sub-contractors be encouraged to aspire to an environmentally conscious waste management plan?
- What products should we be purchasing? And what suppliers should we be supporting?
- Are all stakeholders on board with the waste management plan?
- Do we have accountable systems and documentation in place?
- Induction of builders working on site
- Regular monitoring and reporting systems were put in place
- Nothing left the site unless it was documented
- There was no landfill skip
- Dedication and enthusiasm from students, Marra Construction and sub-contractors who believe that waste minimisation is achievable in the construction environment.