Waste minimisation

Construction and demolition produces about 44% of Australia’s total waste – about 27 million tonnes a year (Department of Agriculture, Water and the Environment & Blue Environment, 2020). Construction waste includes concrete, bricks, plasterboard, metals, timber, glass, plastics, carpet, vegetation, rocks, soil, and sand.

The good news is about 77% of this construction and demolition waste is recovered and 76% is recycled, based on data from 2018-19 (Department of Agriculture, Water and the Environment & Blue Environment, 2020). We can further increase this proportion by looking for ways to reduce, reuse and recycle waste.

Percentage weight of typical building waste materials

Source: Department of Environment & Climate Change NSW (2007) 

Why reduce building waste?

Reducing construction waste has significant environmental benefits. It:

• minimises the amount of raw materials extracted from the environment
• minimises air and water pollution as a result of the extraction and processing of raw materials
• reduces the amount of land needed for landfill
• reduces emissions and leachate from landfill sites which can be highly toxic.

Reducing construction waste also has significant economic benefits. For owners and builders, buying new materials and paying to dispose of old materials is a large cost. Costs to communities for operating and maintaining landfill sites are also high.

Australia has a National Waste Policy (summarised as ‘Less waste, more resources’) and most Australian states and territories have introduced landfill levies to encourage recycling. These levies are charged per tonne of waste.

Basics of reducing building waste

The key to reducing any waste – including construction waste – are the 3 Rs: reduce, reuse, recycle.

Reduce your use of new materials:

• Design and build a smaller home that will suit your needs.
• Make sure the amounts you order are appropriate to cover the build (and should include a little extra to cover damage or offcuts), so that excess materials are not wasted nor sit around a site for long periods where they can become damaged.
• Use prefabricated or modular construction.
• Use designs that make it easier to adapt, reuse, and eventually dismantle the building.

Reuse existing buildings and materials:

• Consider renovating an existing house, rather than demolishing the old and building from scratch (refer to Embodied energy).
• Look for sources of reused materials, such as timber and plasterboard.

Recycle resources that are left over or have reached the end of their useful life:

• Use materials with high recycled content to create a market for recycled resources.
• Check out recycling near you to see what materials you can recycle and how to arrange recycling. Contact:
  – local councils or regional waste authorities
  – local waste station or landfill operators
  – waste recycling contractors.

What can be recycled?

Most materials can be recycled. The following list shows some reuse options. There are many more and the options are growing rapidly:

• Concrete and bricks — Unset concrete can be ‘washed’ out at the plant to remove cement. Sand and stone can be reused. Set concrete and bricks can be crushed and recycled as aggregate for new concrete or road base and fill.
• Plasterboard — Clean plasterboard can be recovered from construction sites and reused. CSR recycles clean plasterboard offcuts from material ordered from them; other companies are considering doing so. Check with your supplier to see if they offer this service.
• Metal – scrap metal can attract good prices, which is an added incentive to recycle any metal. Steel, aluminium and copper piping or wire can all be recovered and recycled. Ferrous metals like steel can be easily recovered from the waste stream using magnets.
• Timber — There is a growing market in the reuse of quality hardwood timber, which can attract high prices. Lower-quality timber (except treated timber) can be reprocessed into particleboard or horticultural mulch.
• Glass — Most glass can be recycled. Construction glass must be separated from other glass such as drink bottles before recycling. Glass may be cut and reused or recycled as aggregate for concrete.
• Plastics — Many plastics can be granulated and reused to make new plastic products. Plastics that can be recycled include – high-density polyethylene (HDPE; rubbish bins, buckets and traffic cones) – low-density polyethylene (LDPE; shrink wrap and bubble wrap) – polystyrene containers, insulation, PVC pipes, fittings, and vinyl flooring.
• Carpet — In good condition, carpet can be sold and reused. It can also be recycled into secondary carpets. Some manufacturers offer a recycling or take-back service on their products. Some carpet can be recycled as a weed barrier or a covering and food for worm farms.
• Vegetation – Woody plants can be chipped to produce mulch, leafy plants can be composted. Many local government or bulk materials companies run schemes to support green waste recycling.
• Rocks, soil and sand – These materials can all be reused for landscaping or fill. These are some of the heaviest materials in construction, so it is a good idea to work out how they can be reused to avoid landfill levies.

To be effective, waste minimisation strategies must be agreed to at the design and construction stages and implemented by all parties involved in building the home. A team approach by the owner, designer, and builder is the most effective way to reduce waste.

Design stage

Decisions made at the planning and design stage will have a major impact on the waste stream for your building or renovation project. This includes decisions such as what to build, whether to demolish, what materials to use, and how they might be recycled.

Project start

Make a commitment to reducing waste from the outset:

• Engage like-minded design professionals (for example, designer, engineer, builder).
• Explicitly state key waste goals before the project starts.
• Get written agreement that specific waste goals or procedures will be followed in the project.

Design concept and development

Consider waste along with other design goals:

• Assess the options to renovate rather than demolish and rebuild.
• Choose the site and building shape to minimise cut and fill.
• Ensure your design is no larger than it needs to be by using space efficiently to meet your needs (for example, multi-function spaces, 3-way bathrooms, well-designed storage).
• Consider a design that is easy to adapt over time as your household’s needs change, providing flexibility to ‘upsize’, ‘downsize’, or improve accessibility.
• Select construction systems with low waste rates, including prefabricated and modular construction (where components are prefabricated off-site).
• Consider construction systems that make it easy to adapt the building and eventually dismantle it for recycling of components.
• Use dimensions that suit standard modular construction sizes to minimise waste.
• Identify salvaged and recycled materials that can be used (for example, consider incorporating recycled bricks and salvaged timber in building and landscape design).
• Consider exposing the building structure as the decorative finish (for example, polished slabs, off-form concrete walls, unpainted brick) to save the need for linings and additional finishes.
• Include multi-bin sorters in kitchen designs so that you can separate household waste for easy recycling and composting.

Architect: Studio203. Photo: John Gollings.

Specification

Your documentation should be as specific as possible to minimise construction and future waste. There are several eco-comparison resources designed to assist in specifying of materials with low life cycle environmental impact (refer to References and additional reading).

Specify:

• materials with known minimum wastage rates (for example, plywood, finger-jointed timber)
• materials with known recycled content (for example, paper and polyester insulation)
• materials with low environmental impact (see eco-certification resources above)
• energy-efficient appliances (for example, washing machine, fridge, dishwasher)
• durable materials and finishes
• waste handling and recycling contractors
• waste streams to be recycled.

Quoting and contracts

Ensure your team is on board with waste minimisation:

• Promote the economic benefits of waste minimisation and recycling to designers and builders.
• Include waste minimisation and recycling performance clauses in the contract.
• Agree which party or parties receive financial benefits of recycling.
• Prepare a waste minimisation plan to be part of the project documentation. Identify the possible types of waste produced, potential recyclers, and methods to reduce or avoid the waste before you begin.

Construction stage

Thinking about minimising waste throughout the construction stage will reduce costs. The Master Builders Association of Victoria and the West Australian Local Government Association have developed construction waste management guidelines that provide useful tips for builders and property owners throughout projects.

Waste management plans

Many local governments require waste management plans before granting development consent. They usually require the designer or builder to estimate the total waste stream volumes from both demolition and construction, and to nominate the means of disposal including the recycling contractor, recycling waste station, or landfill site.

The site plan is often required to show waste storage facilities on site during construction and provide a schedule for delivery or pickup. Plan for waste separation and sorting on site during construction.

Site operations

Plan all materials and waste handling before the project starts, and supervise waste handling practices to ensure compliance:

• Plan locations for depositing and stacking of materials before delivery.
• Form a compound to contain plastic film, cardboard, glue and paint tins.
• Negotiate recycling paybacks with local resource recovery firms. Ask suppliers to collect and reuse or recycle packaging (including pallets) and take back unused materials, such as spare bricks.
• Use waste-aware subcontractors and require trades to dispose of their own waste. Back charge for any waste not sorted or disposed of.
• Use written contracts with all trades that include clauses requiring waste minimisation.
• Separate waste for recycling wherever possible. Provide recycling skips and colour code or label waste skips and protect them from contamination, rain and wind. Lock recycling skips at night and weekends to prevent others dumping rubbish in them.
• Where waste separation is not possible, engage a reputable waste disposal contractor who will take mixed waste bins, sort it on their site, and provide you with a report.
• Provide regular waste bins for food scraps and household waste during construction. Use bins with lids to reduce windblown litter.
• Tidy up the site often. This encourages your trades to do the same and reduces the potential for windblown litter and safety hazards on site.

Materials storage and handling

Optimise the use of the materials you buy:

• Minimise the time between delivery and installation to reduce the risk of damage or theft.
• Check quantity, condition, and quality of goods on delivery. Report discrepancies immediately.
• Reject inferior goods or materials if their quality will result in additional waste.
• Refuse oversupply as compensation for inferior quality or condition.
• Report careless delivery staff to the supplier.
• Have fragile materials and fixtures delivered and installed close to completion date.
• Use prefabricated framing and trusses to reduce time on site before installation.

Concreting

Use recycled products and minimise concrete waste:

• Use concrete with recycled aggregate in all viable applications.
• Buy from plants that wash out cement to allow recycling of sand and aggregate.
• Use reinforcement made from recycled steel.
• Form up accurately and fine-tune estimating to minimise waste. Up to 10% of concrete is wasted.
• Return surplus to the plant for recycling.
• Always form up a small area of path or low-grade slab ready to accept remnants.
• Break remnants into small pieces before final set to allow later use as backfill or recycling.

Bricklaying

Take care of your bricks to ensure they are usable and recyclable:

• Have bricks delivered around the perimeter to minimise the chance of damage from subsequent movement to place of use.
• Use mortar to produce masonry of appropriate strength and durability as required by Australian Standard AS 3700-2018 Masonry structures. Mortars that use hydrate lime mixed with lower cement content are usually softer, thus helping in recycling as well as saving on cement.

Carpentry and joinery

Use sustainable timber and minimise the amount of timber you need:

• Encourage your supplier to find certified sustainable timber sources (for example, certified by the Forest Stewardship Council).
• Use engineered timber products that make efficient use of materials where possible.
• Use offcuts wherever possible.
• Prepare accurate cutting lists before ordering and give joiners a copy of the cutting list to allow efficient timber use.
• Use joinery profiles that can be easily and invisibly joined to reduce offcuts.
• Measure twice – cut once.

Electrical services

Design carefully to reduce wiring needs, and recycle offcuts:

• Use cable products that are highly recyclable and be aware that some PVC coatings in the past used to contain heavy metals.
• Use sub-boards and plan wiring to reduce wiring distances, quantities, waste, and cost.
• Consider pulse switching and intelligent controls to reduce cabling and energy use.
• Recycle offcuts. Strip insulation from copper.

Plastering

Recycle plasterboard in your next project or use a recycler:

• Buy plasterboard from suppliers who recycle.
• Sort offcuts and store on site for return to recycler. Keep offcuts clean and dry.
• Carry useful sized offcuts to the next job.

Glazing

Most glass can be melted down and recycled but requires sorting:

• Separate construction glass from other glass such as drink bottles.
• Keep glass in a separate skip or bin to avoid contamination with other materials.

• Eco-comparison websites
  –    Australian National Life Cycle Inventory Database
  –    Building Products Information Rating 
  –    Ecospecifier Global
  –    Environmental Product Declaration Australasia 
  –    Global Green Tag 
  –    Good Environmental Choice Australia 
• Australian Institute of Architects (2018). Practice notes - materials and waste management. 
• Department of Agriculture, Water and the Environment and Blue Environment (2020). National Waste Reports [PDF], Australian Government, Canberra.
• Department of Environment & Climate Change NSW (2007). Report into the construction and demolition waste stream audit 2000–2005.
• Ellen Macarthur Foundation (2019). Circular economy in cities: making buildings with new techniques that eliminate waste and support material cycles. 
• Harkness T, Prasad D and Fisher M (2002). Waste minimisation in housing: guidelines for designers, UNSW Press, Sydney.
• Hyder Consulting (2011). Construction and demolition waste status report: management of construction and demolition waste in Australia, report for Department of Sustainability, Environment, Water, Population and Communities and Queensland Department of Environment and Resource Management.
• Master Builders Association of Victoria (2004), Waste Guidelines [PDF].
• New South Wales Environmental Protection Authority (2020) Construction and demolition waste.
• Office of Green Industries SA (2015). Government of South Australia, Adelaide.
• Productivity Commission (2006). Waste management, Report no. 38. Australian Government, Canberra.
• Rouwette R (2010). LCA of brick products, J/N107884, Energetics report, V2.1 for Think Brick Australia, Melbourne.
• Shooshtarian S, Khalfan M, Wong PSP, Yang R and Maqsood T (2019). We create 20m tons of construction industry waste each year. Here’s how to stop it going to landfill, The Conversation.
• Sustainability Victoria (2005). Sustainability in action — towards zero waste strategy. Government of Victoria, Melbourne.
• Safe Work Australia. Asbestos.
• United Kingdom Green Building Council (2019). Circular economy guidance for construction clients.
• Western Australian Local Government Association (2015). Construction waste management plan guidelines [PDF].

Learn more

• Explore Designing your home for what to consider at the design stage to minimise your environmental footprint
• Look at Sediment control to learn how soil and sand loss can be minimised on your building site
• Explore the Materials section for ideas on methods and materials for new home construction

Authors

Original authors: Chris Reardon, Emily Fewster

Contributing author: Ted Harkeness

Updated: Philip Alviano 2013