Off-site Construction

Is it the most sustainable construction method?

Because construction emissions account for more than 45% of all the UK’s emissions, there’s a great deal of talk about making the industry greener – and to be fair, great strides have already been taken with new materials, new techniques, best practices and more. And among them is the apparently growing trend for off-site construction. Of course, the concept’s not a new one. The term ‘Prefabs’ was coined in the closing year of the Second World War, when prefabricated homes formed a major part of Winston Churchill’s delivery plan to address the post-war housing shortage. Those homes, though, were never designed to be permanent solutions, and it wasn’t long before, unfairly perhaps, the term ‘prefab’ virtually became a synonym for ‘shoddy’.

That certainly isn’t the case with modern off-site construction, which is already a fully developed, sophisticated and fast-growing sector that already accounts of 7% of the country’s total construction output and worth more than £1.5 billion to the economy.

Its proponents claim many environmental virtues for this approach, which break down into five major sustainability and environmental benefits – not just for the duration of the construction project but also for the lifetime of the building.

• Saves Site Time and Site Pollution

Off-site construction can cut a project’s time to completion by as much as 50%, which makes for far less disruption to local wildlife (and people), fewer emissions and less pollution running off-site and into local rivers and streams.

• Minimise Waste and Traffic

This is a big one! By reducing the number of deliveries and the overall time on-site, you cut traffic to and from the site massively as well as internal traffic – with a consequent reduction in emissions and clear benefits for local air quality (and therefore health) as well as for the environment as a whole. What’s more, because only the pre-made sections specified arrive ion site, there’s almost zero on-site waste. What waste there is will mostly have been recycled in the factory – up to 84% in fact.

• Recyclability

And talking of recycling… Off-site construction makes entire buildings almost 100% recyclable. When a building is no longer required, it can simply be taken apart and reassembled elsewhere.

• Energy Efficiency

Off-site construction could be the single biggest factor in reducing your project’s carbon footprint – typically such projects use 67% less energy overall all than traditional builds.

• Thermal Efficiency

When off-site construction uses precision-made steel frames, they minimise leakage – which means far greater thermal efficiency and for the whole building throughout its life cycle. In consequence, the building will be cheaper to heat and, of course, with lower emissions.

So there’s little doubt that off-site construction has great benefits in sustainability terms, but that’s not to say it’s the only way forward. Indeed, it’s not practical for every project – many smaller sites won’t have the access for extremely large vehicles delivering extremely large modules, for example – and many find the huge amount and intricacy of the advance planning involved a forbidding prospect. Similarly, the fact that every single detail of the project is predetermined at the outset can give rise to problems – because you can’t simply adapt the plans to accommodate unforeseen issues. 

Overall, though, the fact that it’s considerably more sustainable than traditional builds means off-site construction is at the very least worthy of serious consideration at the planning stage of almost every kind of construction project.