Unlike other parts of the trade industry, the plumbing sector has yet to see prefabrication take off. Daniel Williamson explores why this is the case and what can be done.

Trade workers understand the benefits of prefabrication. It creates a streamlined process, saves expenditures and reduces waste, yet in the plumbing industry, prefab remains a more niche practice rather than an industry standard.

As the popularity of modular housing rises, becoming the most prominent way to tackle the ongoing housing crises, in the plumbing industry, prefab remains underutilised.

What is prefabricated plumbing?

Prefab plumbing is not new. In fact, around AD 43, the Romans used the prefab model to build elements to quickly and efficiently build forts in a newly conquered Britain.

Fast forward to 1889, and the concept made its way to France, as Gustav Eiffel designed a ‘temporary’ tower for the 1889 World Fair in Paris that was assembled out of prefabricated iron elements.

Travel another 136 years, and Caroma senior portfolio manager Nick Swan explains that the basic idea of a prefabricated model is to take on-site work off-site as much as possible. Caroma’s prefab model has enabled Caroma to support plumbers with thousands of frames to improve installation efficiency.

A prefab promise

Prefabricated plumbing has the potential to revolutionise the industry – and there is some proof.

Researchers from the University of Melbourne, Dr. Paulo Vaz Serra and Dr. Toong-Khuan Chan, specialise in construction management and are senior lecturers at the School of Design. The pair undertook a research project with the Richstone Group, a Melbourne-based plumbing company, to help implement a design for manufacturing assembly (DfMA) methodology into the business.

“We tested their prefabricated system in a multi-story building in Melbourne, and we recorded around 20% in cost savings,” Paulo says.

“That was something amazing, showing the potential of prefabrication to reduce waste and improve efficiency in plumbing. We could see the future plumbing sector transform into an advanced manufacturing industry.”

Toong-Khuan says one of the major elements that saved time and improved labour productivity was shifting work from on site to a factory: “This also led to better quality assurance, less waste, shorter installation schedules and the requirement for less coordination on site.”

Richstone were able to reap the benefits of prefabrication, having sections of pipework, drainage and other components pre-assembled off-site and installed on-site as modular units.

“In multi-story towers, bringing all the materials and people up and down is time-consuming, labour expensive and can cause major logistical issues,” Paulo says.

“Richstone was very interesting because they were quite innovative and they started to have small, prefabricated pieces, optimising both the drainage and plumbing systems by creating kits which significantly improved efficiency.”

Caroma has joined what they call the “prefab revolution” with its prefab solution, the Caroma Modular Frame Installation Solution, or CAMFIS. This gives plumbers the ability to run their own prefabricated production lines and help solve their labour crisis and drive growth.

By simplifying the prefabrication process down to pre-roughed in-wall units that support and connect Caroma bathroom products, plumbing businesses can install and fit off bathrooms in commercial applications with reduced on-site labour.

With prefabricated assembled frames delivered to their door, plumbers can rough-in prior to site delivery on a standardised frame in factory conditions, deliver to site and then simply click them in to minimise on-site labour, reduce costs and alleviate the headache of coordinating on-site personnel.

Nick also strongly believes in the technology: “The idea is you’re taking on-site work off-site as much as possible.

“Our frames give plumbers the ability to pre-fabricate as much as possible while maintaining flexibility in layout and design.”

Nick explains that significant money can be saved on labour if plumbing companies adopt the prefab model: “If you can do more off-site, not only are you able to avoid other trades and the chaos of on-site, but you can utilise a wider range of labour and avoid union site wages.”

Advanced Piping Systems director Caleb Craig emphasises the efficiency of prefabrication: “By prefabricating your piping system, you’re essentially cutting down on the number of onsite requirements, cutting down costs and de-risking the project too.

The company has experience working with prefabricated plumbing solutions and its pipe systems are fabricated and certified in-house at its Beverley, South Australia workshop before being shipped off to site.

Having components built and manufactured in a controlled environment helped to reduce the chances of errors and improved productivity overall.

So, why hasn’t it taken off?

Despite a few clear examples of its success, prefabricated plumbing faces various obstructions that are preventing it from hitting the ground running.

Where prefab has flourished in other trade industries, plumbing contractors are solely responsible for the design of their own systems. This can lead to minor errors that can then pile on top of each other. Standardisation is a key issue.

“The plumbing sector and electrical sector are still struggling to have prefabrication systems for different reasons,” Paulo says.

“Because they are responsible for the design, each of them is doing the design that they want, and there is no standard model that can be mass-produced.”

Procurement contracts are another significant barrier to the potential prefabrication has on the plumbing industry. The structure of these contracts often shifts the design responsibilities onto subcontractors.

“Under certain procurement contracts, the design is very schematic,” Paulo explains.

“Subcontractors end up taking on design roles, which means they’re not just executing a job, it means they’re responsible for figuring out how to do it, and that makes prefabrication much more difficult to implement.”

Nick also empathises that resistance to change is another key issue.

“Old habits tend to die hard. It’s getting people to change the old ways and adopt new practices, that’s an uphill battle,” he says.

This sounds great, so what’s stopping the industry?

Upfront investment can deter companies from the prefab model. These businesses will need to purchase materials in bulk, design standardised models and create dedicated off-site assembly spaces.

And if one company believes they have a standardised model, without any overarching guidelines, it might not work with other building and construction elements.

This can be considered a burden rather than an opportunity for some and combined with fluctuating demand, it can make it difficult for plumbing businesses to sustain prefabrication initiatives long-term.

Richstone Group attempted to break the mould with their innovative prefabricated plumbing kits. Their approach allowed them to install plumbing systems faster but also gave them a competitive edge by enabling bulk purchases of materials.

Despite their initial success with prefab, the company shut down in part due to financial pressures that were brought to light by the COVID-19 pandemic.

“Richstone was one of the largest in Victoria, but COVID hit, and they had to close,” Paulo explains.

“They weren’t the only large plumber to go under, those with labour on-site were hit the hardest.”

What does the future hold?

While prefabrication has yet to become a standard practice in plumbing, interest in its potential is growing. With housing demand rising and construction costs increasing, it will be “inevitable” for industry leaders to adopt the prefab model according to Nick.

“The guys who aren’t prefabricating at the moment are going to get left behind,” he says.

“If you can genuinely save costs on labour, that means you can be more competitive with your tender and you’re more likely to win that job.”

Paulo agrees that the benefits are clear, but certain actions need to be taken to ensure that prefab does become widely adopted in the plumbing industry.

“For it to work, everyone from builders to regulators need to be on board,” he says.

“Otherwise, it will remain an underutilised and underappreciated opportunity.”

With lofty goals for new developments set by State and Federal Governments, prefabrication is an easy way to speed up the building and construction process.  It appears that without systemic change, prefabricated plumbing will remain an unrealised promise.