An article in Building magazine in July this year, noted that Modular construction “is touted as the future of the building industry, but while the sector is rapidly growing in some areas, there are still obstacles to overcome.” I’ll look at those obstacles presently, but in the meantime, what actually is modular construction?
Well, according to the Modular Building Institute, modular construction “is a process in which a building is constructed off-site, under controlled plant conditions, using the same materials and designing to the same codes and standards as conventionally built facilities – but in about half the time.”
Modular construction comes in many shapes and sizes, from complete 3D structural units, sometimes including load-bearing walls to “frame & infill”, using posts and beams, and prefabricated 2D panels which are taken to the site, craned into position and then connected to form a structure. Typical materials are precast concrete, timber, cross-laminated timber or structural insulated panels. In addition, there are pods - relatively small, prefabricated modules, often fully fitted out, such as bathroom or kitchen pods.
You probably know all this, but for me, in this ongoing blog series looking at the future of construction, the real interest is in how modular construction is just one of many new approaches and how it dovetails with other changes to make construction more productive, efficient and, hopefully, cheaper.
It’s worth concentrating on that last point. It’s not something I’ve really considered so far in this series, but it’s important that we remember that buildings are principally for humans to either live in or use for business/social purposes. Making better buildings, by incorporating green design features, using the internet of things, robotics or other new technologies, is a desirable end in itself. Making them at a reduced cost, so that they are more affordable but still allow the construction companies to make a decent profit, is also clearly a good thing. And modular construction should allow us to do all of these, to the mutual benefit of the builders and their customers.
Time, as we know, is money, and one of the biggest advantages of modular construction is that the components are created indoors, free from weather delays and the work can be done at the same time as site preparation and foundation work takes place. Consequently, the time involved for the entire process is dramatically reduced, sometimes by up to 50%. Also, because of their being built in one facility prior to being shipped to the site for assembly, the indoor work environment is usually far safer than a conventional outdoor site.
Another advantage is that the modules can be used flexibly and disassembled, refurbished and relocated as required, thus reducing the amount of energy and raw materials involved across a number of projects. All good so far, but what about the aforementioned obstacles?
The principal problem to date is cost. That may be surprising, given that much is made of the cost-savings from modular construction, but some studies have shown that the savings from this approach can be minimal for certain types of work (e.g. student housing, budget hotels), while in other areas the costs can actually be higher than traditional methods.
The reasons for this are the current lack of competition in this market and the relatively high cost of the initial investment and the continuing high overheads to maintain the modular production facility. As with all enterprises, a regular flow of work is necessary and costs/prices for modular units can fluctuate depending on demand. There are also issues with the different sizes and weights of prefabricated units. Clearly, there are limits to the size/weight of anything that can reasonably be transported to a project site.
The limited number of suppliers in the market is partly due to the reasons above (high initial investment etc.), but the modular industry is still relatively youthful and it’s expected that as demand and capacity grow, increased competition will follow, leading to the benefits outlined at the start of this article. However, a quick Google search for “modular building Scotland” reveals the extent of this lack of competition. I found relatively few such companies and a more detailed study revealed that only around half of those listed were actually based north of the border.
There can also be constraints on layouts. It is increasingly realised that there may be a trade off where factory fabrication provides the basic units for a house but local, on-site assembly and additional, specialised work then takes over. Greater flexibility can be achieved by combining factory fabrication with sub-assembly and a degree of flexible/bespoke design on site.
Finally, it’s important that the various planning/accreditation authorities keep up to speed with this. Traditional practices, especially at local government level, can take some time to catch up with innovations within the industry, while mortgage lenders will also want to see proof that these new structures have the longevity promised before they make a loan.
All in all, this is an area with huge potential that is slowly, but increasingly, being realised. It will have a major impact on our industry over the next decade.
Chris Peace, MD, Peace Recruitment