Is off-site construction reducing health and safety on-site?
03 March 2020
Despite the rate of self-reported work-related ill health broadly flattening in recent years, the construction industry still accounts for a significant percentage of workplace fatalities and major injuries.
The safety of site operatives and the general public is one of the most critical elements of any construction project but it may be underestimated, particularly when budget overruns and time delays – and their associated cost – come into play.
Over the last five years there has been an average of 36 construction-related fatalities to workers and five to members of the public. Almost 50% of deaths over the same five year period were due to falls from height.
Prefabricated building construction involves manufacturing either a whole building or some of its components off-site. In recent years there has been a rise in modular construction and off-site manufacturing, which has impacted positively on many onsite considerations, including health and safety.
Whilst buildings on a traditional construction site can clearly pose serious health and safety risks, modular buildings are manufactured offsite in quality controlled factory environments, using specialist machinery, which reduces health and safety risks and has the added benefit of reducing waste, leading to a lower environmental impact. On average, 67% less energy is required to produce a modular building and up to 50% less time is spent onsite when compared with traditional construction methods, resulting in up to 90% fewer vehicle movements for the project which in turn, reduces CO2 emissions.
As modular units are delivered to site pre-fitted with any relevant electrics, plumbing, heating, doors and windows and in some cases even fixtures and fittings, the time spent on-site is minimised, thereby accelerating the overall construction process. Health and safety risks can be more easily managed under factory conditions where work is unaffected by the weather, so there is far less of a risk of slips, trips and falls – particularly as work at height is reduced. Most falls in a factory will be from less than a single storey whereas onsite they could be from several storeys high. Components, such as windows, can be pre-installed into appropriate modules inside the factory, without the need for working at height on scaffolding.
Another key consideration is the impact of construction work on the local community. If the majority of construction and assembly is carried out off-site, it means the building site is far more likely to be quieter, cleaner and generally less disruptive – a huge benefit where development is taking place in a residential area or near public buildings such as schools and hospitals.
The number of construction site workers on-site will vary over the course of a build, depending on the different trades required to complete the project. On a large project, such a hotel, there may be as many as 80-120 people onsite at any given time. Onsite construction requires rigorous planning, as it may not be possible for one task to be carried out before another is completed. Environmental factors may also impact on the planned schedule. Prefabricated construction jobs can be carried out independently of each other, in the factory, and then brought together for assembly as required. Off-site construction can reduce project lead times by up to 50 per cent. This is a crucial benefit for contractors who are working to a strict schedule for fitting out, and one which reduces the overall time required on-site and costs associated with that.
Research carried out by Aecom, a global infrastructure firm, has shown that up to 33% of bidding opportunities for onsite construction projects are turned down by contractors because projects are deemed to be too high risk. Prefabrication means fewer people are required on-site to complete the work, which reduces health and safety risks, as there are less people to supervise and more control over safety processes. Although a factory environment still carries some of the same risks as a construction site - such as slips, trips, and the hazards associated with using cranes and mobile equipment - these are reduced because it is a controlled environment – where work is not at the mercy of the elements.
Prefabrication can also be used to manage labour shortages in areas where demand for new construction remains high. This is also helping to manage out the impact of Brexit on the construction labour market, which has created a skills shortage. Off-site manufacturing, however, has a permanent and highly-skilled workforce, with a reduced reliance on subcontracted, temporary labour.
Off-site construction and prefabrication are becoming more of a mainstream method of building as an understanding about its benefits is more widely known. The UA Builders Group predicts that modular construction will increase by 6% globally by 2022. Sweden in particular is embracing prefabrication with 84% of its detached homes being built with prefabricated timber elements.
This type of construction has already proven to be most useful where the alternative is a challenging or constrained outdoor site such as next to a live railway line or at an operational public building. It is fast being accepted that prefabrication can achieve as high a quality construction than on-site methods. It’s safe to say that prefabrication is one trend that’s set to become rooted in the construction industry, as companies continue to look to grow and compete whilst meeting their health and safety obligations.
Industry specialist SafeSite Facilities provides a wide range of safety and security products for commercial and domestic building projects.
For more information, visit www.safesitefacilities.co.uk