Construction rubbish is big business, depending on the angle from which you view it.
It has been estimated that the the construction of an average dwelling generates 17 cubic metres of waste generated. Given Australia’s housing completions exceeded 220,000 over the last year, that could equate to a staggering 3,740,000 cubic metres of waste! Assuming an average dwelling size or 150 square metres, that’s 11.3 cubic centimetres of waste for every square metre.
Worse, this number looks to be on the low side. And if you add the cost of the material making up that waste, the cost of delivering it to site, handling on and off-site, waste removal and tip fees, it’s not hard to get to about $750 per cubic metre. That would equate to $12,750 per dwelling - over $2.8 billion per annum.
Tell that to home buyers trying to scrape together a deposit, organisations looking to find more money to house the disadvantaged, taxpayers subsidising waste built into the cost of negative gearing, or anyone interested in what this might mean to lowering national CO2 emissions. Tell it to anyone blocked on the streets and highways littered with bins and waste trucks.
These staggering numbers would in themselves make the case for fast-tracking the movement toward more off-site fabrication. The Australian pre-build sector estimates that less than five per cent of all construction embraces these methods.
Bear in mind also that if you are considering waste from a life cycle perspective, waste costs can be even higher as they not only include material costs, but also inefficiencies arising from poor planning, design, construction, operation, recycling and eventually, demolition.
Waste Management World’s 2016 ‘state of the nation’ reported that construction and demolition (C&D) waste (typically timber, concrete, plastics, wood, metals, cardboard, asphalt and mixed site debris such as soil and rocks) comprises approximately 40 per cent of Australia’s total waste generation. The good news, they say, is that most is recyclable. Recycling this material is generally cheaper than landfill. Heavy materials C&D waste such as concrete, masonry and steel is very sensitive to landfill levy costs. The sector reports 75 per cent heavy materials recovery rates and rising in many states. But that’s at the backend, after the customer pays and the avoidable CO2 emissions have been produced.
On a positive note, the use of recycled concrete for construction applications is maturing. These days, building demolishers and contractors increasingly sort clean demolished concrete waste and send it to centralized recycling facilities instead of landfills. These facilities crush the clean demolished concrete waste into aggregate. Some projects will purchase the recycled material instead of natural aggregate for construction applications.
The most common applications in Australia are low-grade and pavement. This does not mean that recycled aggregate can only be used for low-grade. Researchers around the world are proving that high-grade applications are possible, durable and economical.
A 2013 study referred by Waste Management World found that on average 21 to 30 per cent of cost overruns in construction projects was due to material wastage. As landfill costs rise, the commercial incentive to better manage materials flow will rise, further improving recovery rates they say. Industries that have seriously tackled their wasteful past have reported a correlation between waste produced and the incidence of quality failures. Lean construction practitioners can also show correlations with time slippage, safety incidents, cost and waste.
The growth in the recycling industry and the downstream services it offers seems great for the economy and the shareholders in waste businesses. There are over 500 active Aussie businesses in the C&D sorting and recovery system. Waste processing is a strong supplier of jobs. The NSW EPA makes this case in its 2015 annual report. So it’s good business.
But, in many ways, it all seems a bit like shutting the gate after the horse has bolted.
When Australia is pressing for new innovation, look for a politician excitedly turning up for a photo opportunity when developments such as Optical Waste Sorting occur. This is not to say these backend waste measures are not important. Waste is still a huge challenge and minimising its impact will always require new innovations. But the better approach for the construction industry must be avoiding waste in the first place.
Initiatives such as the Burbank Homes + HIA + RMIT’s Centre for Design and Society (CfD+S) partnership to lead a project aimed at achieving a zero waste dwelling construction seemed rich with potential. But not much of an enduring nature seems to have resulted industry-wide. The project report detailed the possibilities in its findings:
- The first house generated a total of 9,126.1 kilograms of waste. This waste generation was predominantly driven by off-cuts and excess bricks and mortar, concrete roof tiles and plasterboard. A suite of avoidance design strategies was developed by all stakeholders. The implementation of these design (pre-build) strategies reduced waste generation by 6,603 kilograms, representing a 72.4 per cent reduction.
- Non-acceptance of over-deliveries (beyond the specified order) and take-back of recyclable waste by contractors combined with implementation of other waste mitigation initiatives contributed to an additional 2,492.4-kilogram reduction in waste being sent to landfill. The total amount of waste sent to landfill from the final house was quantified to be 30.8 kilograms, representing a 99 per cent reduction. So, it’s possible.
The report concluded that successful implementation and ongoing reduction in waste generation in the residential construction sector more broadly faces a number of challenges. These include addressing the culture of over-supply, improvement in material quality systems (both by suppliers and customers) and influencing consumer choices, which underpin material selection. For example, a consumer choice for use of concrete roof tiles over metal roofing will likely result in increased waste generation, it found.
A 2011 Australian Housing and Urban Research Institute (AHURI) and RMIT Research Centre report titled Australian suburban house building: industry organisation, practices and constraints adds further insight into why the industry conducts itself the way it does. The report looked into the increasing durations needed to construct residential dwellings.
By and large, on-site trades are self-organizing, they come and go to suit their piecework packages, they show limited if any interest in any other trade inputs, leave their droppings behind and move on. It’s little wonder that Australian residential construction has such a variable track record in delivering compliant, quality construction to the industry’s customers. Again the case for smarter prebuild planning and off-site fabrication presents itself.
If you deploy wasteful, careless construction methods, what hope does quality have?
The Burbank project did not address the growing multi-unit market, where developers and their contractors make all the choices and supply chain decisions. There is no end consumer choice involved in this process, despite the reality that their consumers still pay for the same waste and quality shortcomings as they do for the industry’s traditional detached and attached housing counterparts.
Multi-unit makes up nearly half of the residential housing market these days. Multi-unit sites have limited space, but they would appear to generate as much rubbish. They need to eject their rubbish fast. The waste industry is there to help.
Governments were once the leaders in using waste disposal price levers to turn around the industry’s wasteful practices. Once the price levers were in place, it seemed like a good idea to sell off government and local government owned waste facilities with their now attractive income streams. Private waste companies are driven by increasing profits and growing their markets. While governments might still have interest in sanctioning waste handling charge increases, we’ve heard of no waste industry protest over the steady growth in waste either being recycled or sent to landfill. All the while, the industry’s customers pay.
Despite the green claims industry makes about the growing amount of the waste it creates being recycled, there is no avoiding the fact that this waste costs consumers, who have no hand in avoiding it in the first place. But the bigger the downstream waste industry gets, the more profitable it is for their shareholders. It all seems a bit perverse.
The construction industry is the largest consumer of raw materials globally, and yet less than one-third of construction and demolition waste is recycled or reused, says a new report by the World Economic Forum. In the US alone, about 40 per cent of solid waste comes from construction and demolition.
Australia is one of the 10 worst offenders in the OECD when it comes to generating solid waste. The construction industry is a leading contributor, throwing out a third of our gross national pile of (potentially reusable) junk. Residential housing accounts for 38 per cent of global construction volume; transport, energy and water infrastructure for 32 per cent; institutional and commercial buildings 18 per cent; and industrial sites 13 per cent.
There can be no more graphic demonstration of the cluttered minds who still operate business as usual than from the images captured every time we visit construction sites. By far, traditional residential constructors are the worst, and the size of the builder does not seem to matter. There are only few examples of genuine waste separation and recycling intent to be seen on-site.
Government and environmental groups are often at a loss when trying to effect lasting industry culture and practice change. The levers of legislation don’t seem able to overcome the motivations that sustain old industry practices. Those motivations seem immune.
As the AHURI report found, when no one puts a price on construction time and practice, there is limited incentive to change. An average dwelling takes nearly a year to complete. Some developers who apply a more professional approach to time management can halve traditional construction times. In Europe, those times are halved again. There appears to be a correlation between fast construction and less waste on the residential projects.
But the Australian construction industry is in an awkward transition phase. There is still resistance to the new rules of modern construction where smarter + better quality + faster construction + less waste + fewer injuries = lower cost. A better deal for customers. Even those pioneering in pre-build construction don’t see cost coming down, at least not just yet.
In the interim, the industry deals with the here and now. Capture and recycle as much waste as possible. Lots of feel good money gets pushed into the recycle space. It seems like governments need to be seen to be doing something. Planet Ark has a web site pointing to all of the recycling locations nationally. They do their best to encourage the leaders in this space, but one can’t help wondering if the industry really cares. It’s just rubbish to most.