(Image: Private Media)

This is part two of a series. Read part one here.

The biggest contributor to Australia’s waste crisis isn’t households or fashion — it’s construction. Early in the pandemic, to boost the economy, federal and state governments introduced stimulus packages and programs to get Australians building. 

In June 2020 HomeBuilder was announced, one of the biggest stimulus injections the housing industry had ever seen. Anyone wanting to build a home or substantially renovate one had access to a $25,000 grant. More than 137,000 Australians signed up at a cost of $41.6 billion. 

While data has yet to be released, it’s likely this construction boom had a huge impact on Australia’s waste production with tonnes of concrete, brick and glass tossed. 

How much waste is generated? 

In 2018-19, Australia generated an estimated 74.1 million tonnes of waste, just 43 million tonnes of which were recycled. Masonry waste made up 44% of that. Sydney, in particular, faces pressure to cope with construction waste.

Using this data on masonry waste, we can paint a rough picture of how much extra waste has been produced. (These figures assume dwellings produce the same waste as that from building roads, bridges and other infrastructure.) 

Across June and July in 2018-19 there were 22.9 million tonnes of masonry waste produced, and 205,216 dwellings built. That equates to about 111.5 tonnes of waste per dwelling on average.

Across October and December in 2020-21, 220,842 dwellings were built reaching a record high in the final quarter and creating an estimated 24.6 million tonnes of waste — an extra 1.7 million tonnes or an increase of 7.5%. 

RMIT project management associate dean Tayyab Maqsood tells Crikey most is made up of concrete and bricks, followed by plaster, timber and glass.

“I think it’s fair to say this COVID-19 has contributed to a substantial increase in the waste,” he said. 

Where does all the waste come from? 

Most of Australia’s building takes place on undeveloped land, Maqsood says. Houses being demolished or rebuilt don’t contribute to a waste increase nearly as much as new developments. 

“In Australia, if we have an old building, we generally make it heritage-listed,” he said. For newer buildings, much of the existing structure is kept and added, unless it is structurally unsound. 

Some studies have found more than 30% of construction works are related to rework; Maqsood says another 10-12% of waste is due to overordering materials. Rework accounts for up to 6.4% of a percentage of a contract’s value. 

“Rework means you do something that is not up to the specification that you have to demolish … while builders will always add around 10% to the top of their [building material orders] for inventory management,” he said.

Some of this extra material is kept by owners for landscaping or other projects, but the rest goes to waste. 

However, Housing Industry Australia chief economist Tim Reardon disputes that construction generates mass amounts of waste from overordering and rework, especially across the pandemic. 

“There’s no such thing as overordering materials at the moment,” he said. 

Much of Australia’s building materials are produced onshore but the surge in demand for new houses has created a shortage. Timber costs have more than doubled, and the Australian Forest Products Association has warned that by 2035 Australia will be 250,000 house frames short of demand — a production shortfall equivalent to the combined size of Geelong and Newcastle.

“It is crisis points like this where we do see significant investment in alternative building methods,” Reardon said, with many new houses built with steel frames instead of timber. 

While Australia’s population growth has driven to a near standstill, he says the housing boom was likely to continue, driven by demand as more people seek to move into low-density housing following lockdowns, and an ongoing rental crisis and housing shortage.

National sales of detached homes increased by 11.3% in December, the fifth consecutive monthly increase in new home sales. 

What can be done? 

Masqood says that to limit the number of extra materials ordered and to help avoid rework, the industry had to turn to building information modelling, using augmented reality to 3D-model a building before construction beings. 

“Using modelling, we can minimise mistakes made and rework, then model how much excess will be generated to use it in a different project,” he said. 

“We can also prevent accidents if we figure out the issues that might happen during the building process.”

There’s a silver lining: in 2018-19, 82% of masonry waste was recycled. But Masqood says efforts had been hampered by staff shortages — recycling can be more labour-intensive, and plans to develop construction waste facilities in NSW have been met with a backlash byresidents. 

Engineer at brick recycling company The Brick Pit Raj Mehta tells Crikey demolition experts have to take extra precautions when removing recyclable materials to check for contaminants and maintain material quality. 

“We generally only have 10 to 15% waste in bought bricks,” he said, although he added the company had stopped buying bricks due to labour shortages. 

“We have so much stock, but not enough workers,” he said. 

Friday: fast fashion’s impact on the waste crisis.