Most people who think about modular construction picture the walls, the roof, the fitout. What they rarely think about is what sits underneath all of it.

John Davis thinks about it constantly.

Davis is the director of MMC Modular and the creator of ModFloor, a light gauge steel chassis system that is changing the economics of modular building in Australia and increasingly, around the world. His starting point was a problem most in the industry had accepted as unavoidable: welded steel chassis are expensive, slow to produce, skill-dependent, and prone to the kind of flex under transport that cracks tiles, pops windows and sends builders back to remote sites with five-figure remedial budgets.

“I could always see potential for a chassis system that replaced welded steel,” Davis says. “I just didn’t know how to fix the problem.”

He eventually did. And what followed was not just a product. It was an entirely new system for how modular buildings can be manufactured, designed, costed, and delivered.

From Darwin to Darwin Technology

Davis’s career in construction began in the Northern Territory in 1974. He moved to Brisbane in the 1980s, built traditional residential homes across southern Queensland, then took Queensland design principles into New Zealand in 1998, where his company was building hundreds of houses a year within months of launching.

It was in New Zealand that he first encountered light gauge steel framing at commercial scale, and he saw immediately where it could go. He opened a steel framing factory for his own product, then in 2001 launched the first light gauge steel framing company to enter the United States market, setting up in Miami-Dade County because its wind load requirements, modelled on cyclone codes adapted from Darwin, matched what his system was built for.

“We went there because we could build cyclone proof and hurricane proof,” he says. “They couldn’t quite cope with the Darwin code, they had to water it down a bit.”

The work took him into modular construction in Orlando and the Bahamas. When he returned to Australia in 2012, he brought back a clear understanding of what modular manufacturing was missing. And when he acquired a large roll-forming machine for light gauge steel mid floors, the solution to the chassis problem became visible.

“As soon as I saw it, I realised we had the potential to solve this modular chassis problem.”

Three years of development followed. ModFloor launched. ModFloor Plus followed. Patents were secured. QBuild adopted the system for modular housing in Queensland. And then Davis started building his own roll-forming machinery.

Why the Chassis Matters

For builders unfamiliar with the modular space, the chassis is easy to underestimate. Davis is direct about why that is a mistake.

Traditional chassis options are timber, assembled by qualified carpenters, or welded steel, put together by welders. Both are expensive, both are slow, and both have a deflection problem.

“When you’re building modular, you pick up a module, put it on a truck, and take it to a site,” Davis explains. “A lot of chassis flex. That results in plasterboard cracks, tile cracks, windows that move. The cost for modular builders of that can be horrendous.”

He has had modular builders tell him they allocate between $18,000 and $25,000 per remote job specifically for remedial work after transport. Those are not outliers. They are baked-in costs on any delivery to regional Australia.

ModFloor removes the deflection problem. Independent load testing put deflection at an average of three millimetres under a 50 per cent overload condition, with most readings sitting between one and two millimetres. Davis says customers shipping from Queensland to South Australia and Western Australia report negligible internal damage on arrival.

The system also removes the skill dependency. No welding. No measuring. No cutting. Components arrive ready to assemble, and a crew of three can complete a 15 by 4 metre chassis, including the insulated floor panel, in around three hours.

“I’ve trained clients’ guys to put it together in half a day,” Davis says. “Unskilled labour. You just need to cut the piece of string and clamp, and it’s done.”

Building the Machine to Build the System

Davis is not just a product designer. He is a manufacturer who, when the available machinery could not meet his quality and speed requirements, built his own.

MMC Modular now produces a range of five roll-forming machines, including a high-output model capable of producing five different profile sizes automatically, switching between them in under a minute. Production speed with the new machines is approximately 500 per cent higher than previous capacity with the same number of operators.

A client in Western Australia who previously took three and a half days to complete a welded chassis is now producing three in a single day using the same team.

The machinery is also priced to compete. Davis says the flagship roll-former comes in at three to four hundred thousand dollars below comparable machines on the market, and nothing else on the market does what it does.

A System Around the System

What makes MMC Modular genuinely unusual is not just the chassis and the machinery. It is the full-service infrastructure Davis has built around them.

Under the MMC Modular umbrella sits an architectural and design service called Your Workshop, which handles modular design, costing, council applications, and subdivision layouts. Builders using the system access designs through an online portal, mark up plans digitally, and receive files ready for the machine without needing in-house engineers or detailers.

Critically, designs are licensed once and used as many times as needed. A modular builder who commissions a chassis and frame design through the portal pays once, then rolls it out across every future project of the same type at no additional cost.

Davis is also building out a just-in-time ordering system, where a client in Perth can order steel directly from a local supplier in WA through the MMC portal, with the order processed automatically and delivered to the factory on schedule. Insulated floor panels, roofing, and other materials are being added to the same portal, all sourced locally.

“Speed is really what it’s all about now,” Davis says. “Time is money. Getting things on time. You don’t want products sitting in your factory for a month.”

Solving Problems That Haven’t Been Named Yet

Davis has a habit of identifying consequences of the modular system that others have not yet framed as problems.

Crane costs are one example. A Victorian client recently moved from a 200 tonne crane to a 100 tonne crane simply by switching from a welded chassis to ModFloor Plus with light gauge steel framing. The cost saving is substantial, and it was not the primary reason they changed systems.

Concrete elimination is another. In regional areas where getting an agitator to a site is prohibitively expensive or logistically impossible, MMC’s system can build a complete structure without a concrete slab. Davis is about to release a modular garage designed to be driven into, certified for use without any concrete in the floor, aimed directly at remote builds where access and cost rule out traditional slab work.

Land lease compliance is a third. Under Australian residential tenancy legislation, dwellings on land lease sites are legally required to be relocatable. In practice, Davis says the code has been widely ignored, with the result that litigation is now starting to emerge against land lease developers who have built on concrete slabs that cannot be moved.

MMC’s response is a ModFloor Plus system engineered for on-site assembly that can also be top-lifted and relocated, and which satisfies councils requiring proof of relocatability before granting development approval. Davis is releasing that system imminently.

Multi-level modular is next. MMC has engineered a light gauge steel stacking system, fully patented, requiring no structural steel, that allows modules to be placed on top of each other and disassembled later if needed. It is currently certified to three levels for practical deployment.

Davis describes a project in Victoria where a client is building 12 one-bedroom units on a 1,400 square metre lot, stacked two high in six rows, with carports and a service road. All 12 were pre-sold before manufacturing began. The price point is under $400,000 per unit.

“It opens up another solution line for this affordable housing problem we’ve got here,” he says.

What This Means for Builders

The practical implications of what Davis has built extend well beyond modular specialists.

For any builder considering modular as a production pathway, the traditional barriers, skilled labour dependency, deflection and transport risk, high capital cost, complex design requirements, and the need for in-house engineering capability, are substantially reduced by the MMC system.

For builders already working in modular, Davis offers a live comparison. Three guys building a 14 by 3.5 metre chassis with MMC’s steel frames and trusses complete the job in a day. That same task using timber or heavy steel takes a larger, more skilled crew significantly longer.

Davis also draws attention to something builders across all sectors often underestimate: the compounding cost of not knowing your numbers. He has seen modular operators carry large losses on remote deliveries because they never tracked the true cost of remedial work. His system does not just reduce that cost. It makes it visible.

“Builders generally don’t have that inherent skill for doing their costing properly,” he says. “I know, because I’ve made the same mistakes myself.”

His answer is to build the costing capability into the service. Your Workshop handles takeoffs, cost modelling and council submissions. The machinery bundles in the design and detail files. The portal handles procurement. The goal is a modular business that can operate without specialists it cannot afford to hire.

A Different Kind of Construction Future

Davis’s view on where the industry is heading is unambiguous.

Skilled trades are disappearing. The cost of on-site labour is rising. Approval timelines are extending. The housing shortfall is widening. His conclusion is that modular construction, properly systematised, is not one option among many. It is the direction the industry has to move.

“The only way Australia is going to overcome this housing problem is with modular,” he says. “You can’t get the man off the street. The costs are so expensive.”

He acknowledges the resistance. The modular industry, he says, suffers from what he calls FONS: Fear Of New technology Syndrome. Getting operators to change systems they have used for 20 years is slow. But once they switch, they do not go back.

He is also candid about what modular manufacturing requires mentally from people who have come from traditional building.

“Modular construction is not building. It is manufacturing. You’ve got to have a new thought process. You’re producing on a production line, not building something out on site.”

That shift in mindset, he argues, is as important as any system upgrade. And it is the one thing he cannot roll out of a machine.

The Good Builder Takeaway

John Davis did not set out to build a portfolio of products, a suite of services, and a range of proprietary machinery. He set out to fix one problem with a chassis, and kept following the consequences.

What he has built is a system for how modular construction can actually work at scale, in Australia, in 2026, without the skilled labour that no longer exists, without the deflection costs that eat into margins, and without the design and engineering overheads that price smaller operators out of the game.

For builders looking at modular as a production model, for trades considering where their skills are going to be relevant in five years, and for suppliers wondering what genuine product support looks like, the conversation Davis has been having quietly across the industry for a decade is worth understanding.

Author: TGB Editorial