Modular construction has been around for some time, but it is questionable as to whether we fully appreciate the benefits and explore the opportunities it has to offer.
As with any approach, there are pluses and minuses, but some of the pros include:
Reduced Site Programme and Lower Overall Costs
The same quality of materials for finishes are used as with site-built construction, but since up to 80 per cent of the building is built and inspected off-site, the amount of time required for completion is dramatically reduced. Less construction site time reduces waste, the chance of weather delays, occupation of infrastructure/public space and material damage. Fewer subcontractors on site reduce site supervision costs, as well as often overlooked costs such as waste removal. Reduction in construction time frames of 30 to 50 per cent are easily achievable.
OHS issues are significantly minimised as the majority of the labour force works in a controlled environment more related to a factory production line, rather than on a continually-changing traditional site. Even if the end product is a tall structure, labourers can work close to the ground and then crane the module once completed. Beyond health and safety concerns, security risks related to theft are also reduced, cost overrun risks are minimized, as are insurance and other “hidden cost” liabilities.
There are still questions raised by the industry, however.
Some fear that modular construction will lead to soulless, repetitive developments. While it is true that one of the benefits of volume-based construction is the ability to churn out buildings quickly without the need for redesign, there is still the ability to be creative and consider the final output as a customisable solution. Some modular providers, for example, champion the flexibility of their modules to be utilised in “open plan” office spaces.
Façades can easily change the characteristic of a building through the use of solar or coloured composite panels, for example. Internally, finishes are easily tailored to specific tastes or uses. Meanwhile, the spaces in between buildings can be altered in response to specific climatic and location conditions through intelligent planning and urban design or creative landscaping.
The spaces in between are also interesting when considering the impact on the surrounding community. Since most of a modular building’s construction occurs off-site, there is less impact on the neighbourhood. Traffic from trucks and cars, delivery materials and subcontractors is dramatically reduced, as is the noise pollution generated by site-built techniques.
Of course, there are questions as to how green modular construction is, and it is important to avoid making sweeping statements in this regard. On the projects we are currently working on, for example, there is more steel content and transportation involved. That being said, through proven manufacturing processes, modular factories are able to construct tighter buildings with less air infiltration. As a result, modular-built buildings will typically outperform similar buildings constructed with traditional techniques. In addition, there is also reduced on-site wastage.
The perceived downside of modular construction is that each module has to be highly engineered for the same level of accommodation. Modules need to be designed to withstand significant transportation forces but the payoff is greater structural integrity in the end for the completed building, as well as higher inherent strength.
The building also has to be considered holistically from the outset and the structure has to work around materials and adjusted around the services. This means collaboration is essential with suppliers, especially with regard to fire ratings and the integration of various systems. A level of professional involvement is required by all disciplines for both the design and assembly of the individual modules. All of this comes with costs.
However, clients must stop thinking as they would as if they were developing a traditional building. Instead, they should think of the engineer as a design leader with offsets made against lower costs paid out to the contractor and sub-contractor usually responsible for the shop detailing, as well as the lower construction costs.
So where are some of the opportunities across Australia to utilise this method of design and construction?
The mining boom and energy and gas sectors are currently sucking resources dry both in terms of materials and manpower, leaving local trades in short supply. With many mining facilities being simple tin sheds with shared facilities, modular construction could deliver a quality product where materials are at a premium and provide workers with a much higher level of accommodation than they currently experience.
Other high-volume needs where building repetitiveness could be seen as acceptable while improving on current product quality and saving on cost and improving construction times could include social housing, holiday parks and aged care units.
There are a plethora of unused, restricted inner city sites in Australia’s big cities that are seen by developers as hard to unlock but which could exploit the potential of modular buildings. It is only the question of crane access, which could really challenge the simple vertical stacking of modules on these difficult sites.
Existing structures also offer opportunities. Modules could be added to car park structres, for example, to diversify the use of the existing structure. It is much easier and cheaper to design a module to land on the existing column grid than it is to tackle construction of a complicated, space-consuming and expensive transfer level on which to maximize the yield. This is especially pertinent for CBD sites.
With the forthcoming Commonwealth Games on the Gold Coast, temporary accommodation for athletes and temporary hotels for visitors could be an option at the level of quality required. This type of use is ideal for the ‘plug and play’ potential of modular buildings while no site welding means they are easy to decommission after the event. Although economics would have to be explored, there would then be opportunities for simply moving these buildings to another event or site.
Modular buildings have come a long way and there is certainly more to come.