Prefabricated, or “modular”, construction offers a high quality, affordable solution for public and residential buildings, with advantages for gender parity and far better environmental outcomes. So why do people still think it’s a tad “cheap and nasty”?
If you’re looking at the advantages and disadvantages of prefabricated modular homes, you might be tempted to take “cheap” at face value.
But for professionals who work in the construction space, when it comes to prefabricated construction, cheap doesn’t equate to nasty.
As with all new buildings in Australia, there is a certain compliance criteria to meet before receiving occupancy permits, and prefab is no exception. Modern prefabricated buildings are built to the same standards of quality and functionality (if not higher) as any other building.
Builders are able to produce “very high-end luxury homes using their prefab units”, Priyan Mendis tells The Fifth Estate.
Mendis is professor of infrastructure engineering at Melbourne University and director of the ARC Training Centre for Advanced Manufacturing of Prefabricated Housing (ARC CAMPH), the centrepiece for collaborative, eco-friendly, prefabricated housing research in Australia.
“Already, the quality in low-rise prefab buildings produced by many prefab builders is superior to traditional builds,” agreed Dr Tharaka Gunawardena, research fellow of infrastructure engineering at Melbourne University.
But while these high-end homes may be high quality and look more expensive, they cut costs considerably.
In the long run, “financial benefits are immense and become a rather obvious choice,” Mendis says.
Despite this, modular construction and prefabrication represents just three per cent of Australia’s $150 billion construction industry – compare that to in Europe where countries like Sweden build 84 per cent of their houses using prefabricated elements.
“In Australia, one of the reasons prefab has been held back is because it is seen as a cheap and nasty way to build, so people avoided it,” Gensler’s design director, Ken McBryde, says.
Going back in time, prefab construction was often seen as cheap and nasty because of its association with demountable buildings that were used as temporary accommodation and semi-permanent structures.
These “dodgy” structures were often seen in mining towns and in schools, says Damien Crough, co-founder and executive chairman of PrefabAUS, which is the peak body for Australia’s building prefabrication industry.
But nowadays, at least within the construction industry, perspectives are slowly changing.
The market for prefab buildings is expected to grow at a compound annual growth rate (CAGR) of more than 7.5 per cent until 2027, due to a boom in construction building investments during the pandemic.
A streamlined factory-floor process
When it comes to construction, there are essentially two options. First, “stick built” structures that are built from the ground up on site, and second, a “prefab” homes that are built in a warehouse and assembled on site.
The term “prefab” simply refers to structures that are built, prepared or assembled away from the building site. A window is a good example. In the modern world, you would be hard-pressed to find a building that doesn’t contain prefabricated elements. So when it comes to a building, we’re talking about degrees of prefabrication.
“Most buildings have an element of prefab already… because builders recognise the benefits of the approach, and the tech is there to allow it,” Crough says.
Prefab is considerably cheaper because the production process is more streamlined, less labour is needed, there is less wastage. Plus, it is much faster to put together a house that has been pre-fabricated on the warehouse floor.
“The more you prefab, the more certainty you have about quality and improved impact on the environment, because there is far less waste when you build off-site,” McBryde says.
In fact when assembled on site with prefab construction techniques, houses may be finished within a matter of days or weeks, not months. Prefab construction is almost “like theatre”.
“It’s beautiful and elegant,” he said. “It was conceived by some of the most wonderful, forward-thinking architects.”
“From quality, speed, sustainability, and gender equity, it’s clearly the way forward”.
Over time, these benefits mean that prefab is becoming more popular.
“I think that stigma and preconception is gone now,” Crough says.
“Consumers are more educated, want high performance and sustainability. And prefab is delivering on that.”
A solution to the affordability crisis?
“Residential is where the most growth is happening,” said Crough.
“Due to a 30 per cent increase in materials and labour shortages, prefab is starting to make sense.”
“We need to build a city the size of Canberra every year to keep up with population growth,” Crough says.
Due to the cost competitiveness of prefab, it proves to be an alternative that just makes more sense in the current housing affordability crisis.
Mendis thinks that prefab may be the only viable option moving forward.
“Traditional methods will very soon disappear from the construction industry as skilled labour is fast becoming a scarce resource. Very soon, prefab and offsite manufacturing will not be an option anymore. It will be a necessity.
“Prefab is now capturing the market for many public infrastructure projects including railway stations, schools, police stations, and hospitals in Australia. … Children would leave for school holidays from their old building and walk into the new prefab building as they return from their holidays,” he explained.
Crough points to new procurements from modular schools in Victoria, to quarantine facilities in Western Australia and Victoria, to mental health facilities in Victoria. In sectors like aged care, health care, retail, commercial and defence, there are huge amounts of prefab being used.
Resilient housing in remote areas
PrefabAUS is working with the Bushfire Council of Australia to create a model for a bushfire resilient house. It is also working on flood resilient floating houses as well.
Prefab is being used as a solution for affordable housing in remote areas – but that doesn’t mean that it is less high quality.
For ARC CAMPH, this construction process delivers a solution for social housing in remote Indigenous communities. The training centre has been working on developing concepts for social housing including housing for Indigenous communities.
“Prefab is ideal for remote aboriginal buildings. In a COVID environment, if you’re building in a community for extended periods of time, it can be very dangerous for vulnerable communities. If you can create a system that is easy to set up, you only need one or two people and they can put up a building in a matter of days,” McBryde says.
From 2016 to 2020, with funding from the $4.0 million Industrial Transformation Research Training Centres scheme, ARC CAMPH engaged with 12 industry partners and four universities (including The University of Melbourne, The University of Sydney, Curtin University of Technology, and Monash University) in delivering a much-needed cutting edge for Australia’s budding prefab industry.
“Twenty per cent of the world’s population lacks adequate housing. We cannot solve it with conventional site-based construction methodology. We need ways to build in days, not months” McBryde says.
Less waste produced
In addition to helping create climate resistant housing, prefab has far less impact on the environment, mostly because it eliminates the waste problem on site.
It is far easier to reduce waste as elements are cut to size, and to properly recycle waste elements than on a traditional construction site.
Gunawardena says Australia now faces a serious waste management problem.
“Prefab buildings are reusable. This adds a whole new dimension to its sustainability compared to traditionally built structures. Designers of prefab buildings are mindful of the end use and disassembly of the building.
“On construction sites there is a big problem with waste of materials. “A lot of prefab will produce no waste, and it is all cut to the size needed. Also, it is easy to pull apart and reuse or recycle,” Crough Crough.
“We are also currently looking at upcycling waste materials to engineer products and systems to be used in the prefab industry,” Gunawardena says.
For example, Gensler is working on a prefabricated Blue Mountains ski resort project that will feature recycled roadside crash-barriers.
Gender parity on the construction site
Prefab may offer a solution to delivering greater gender equality on the construction site, and break through that proverbial “concrete ceiling”.
At the moment women make up 2.5 per cent of tradies and on-site construction workers, according to Monash University. At the current rate it would take around 200 years to achieve gender equality in the construction industry.
“I can personally attest to the truth behind this statement,” said Gunawardena.
“Most of the construction happens within a factory… more women [are] engaging in construction now as skilled labourers (such as carpenters, welders), project managers, supervisors, and engineers.”