Off-site Construction – A growing global trend for a forced necessity
Over the next five years, the UK construction sector will increasingly use pre-fabrication to complete project elements and components.
However, this new swing towards off-site construction is not necessarily a retrogressive development, as much has changed since the methodology’s previous heyday for notoriously poor post-war building and rebuilding.
Where does this new demand for prefabrication come from, what are the advantages and how does it underpin the future of UK construction?
What does it involve?
Some of the biggest names in the sector – including construction giants Laing O Rourke and Balfour Beatty – are leading the way on finding economies of scale in prefabricating elements of construction projects.
Off-site construction involves using a secondary location to plan, design, fabricate and assemble components, usually in purpose-built or even ‘pop-up’ factories (fabrication facilities of this sort can be moved around to be as close as possible to major construction sites, and these are sometimes referred as ‘flying factories’).
Alternatively, construction firms and architects establish beneficial working relationships with organisations able to arrange construction of components, to be transported to sites, for amalgamation with on-site engineering and assembly work.
Origins of the concept
Design for Manufacture and Assembly (DFMA) that supports prefabrication for buildings and civil engineering works is by no means a new concept.
After the second world war demand for housing outstripped supply – much as it does today. The construction industry turned to off-site sources of wall panels and flooring systems, in particular, to erect high-rise apartment blocks.
One of the main reasons there was a swing away from this methodology was that the limited outsourcing options available and accelerated building processes led to homogeneous, and, in some cases, highly unattractive buildings. It was also blamed for lingering faults in building infrastructure.
Why is it now a necessity?
The principles of off-site construction are now being revisited, as an important way to meet modern challenges; especially to manage construction labour costs and shortages.
In 2016, the Farmer Review of the UK Construction Labour Model (commissioned by the Construction Leadership Council in partnership with the Government) urged companies to ‘Modernise or die’. Within this document, ‘pre-manufacture’ was discussed to manage labour levels and risks. It refers to needing to explore ‘component level standardisation and lean processes, through to completely pre-finished volumetric solutions’.
It’s a topic also discussed in a 2018 report from the House of Lords Science and Technology Committee entitled ‘Off-site manufacture for construction: Building for change’. This addressed the current housing crisis, the fact the UK is falling behind European levels of construction productivity and the serious labour deficit. It urged the construction industry to find robust and meaningful solutions.
What are the benefits of off-site construction?
On the surface, it can appear that fragmenting fabrication of components in this way adds to the complexities of construction. Instead of manufacturing items on-site, companies must juggle additional DFMA issues, and component handling, transportation, crane-age and assembly issues.
In fact, off-site construction offers important time efficiencies. Items can be designed and created in tandem with on-site activities, rather than waiting for space, machinery and manpower to become available.
It reduces the amount of labour needed on-site, and lowers risks factors, enabling construction firms to deliver on construction milestones more efficiently.
Off-site construction methods can also improve standardisation of components. Quality can be higher, and waste levels reduced if components are prefabricated in specialist manufacturing environments.
More factors driving off-site construction
The trend towards relying more on pre-manufactured and assembled construction components is an opportunity – to standardise, and reduce time, costs and wastage – but also a solution.
There is a substantial labour shortage in construction and the issue is likely to worsen post-Brexit.
Fabricating components off-site at specialist locations can manage skill gaps too and reduce the amount of ‘downtime’ companies have in their existing pool of professionals.
Construction firms could potentially offer a wider range of components and finishes in pitches and plans too, by utilising the DFMA skills of external providers.
Off-site construction is particularly relevant for items that are needed in large quantities, and that rely on repetitive processes to produce consistent dimensions; for example, façades for larger buildings or extensive housing developments.
Making off-site construction effective
One reason why major construction companies have previously concentrated all their fabrication and assembly on-site is that it hasn’t always been easy to find manufacturers with the necessary skills, equipment or capacity. Setting up their own factories can be a costly investment.
For façade design and construction, construction companies are relying on the manufacturing excellence and competitive costs that alsecco offer. We work with some of the biggest names in European construction and architecture to produce facades off-site; to improve project performance, margins and management. Get in touch to discuss how we can support your off-site construction project.