Offsite manufacturing for construction – or just ‘offsite’, for short – can reduce costs, provide more certainty over the schedule, overcome technical obstacles or provide a combination of these benefits. It’s an approach that is increasingly used for buildings. Walk past the building site for a major city-centre development, and you could well see components such as plant rooms, bathroom pods, floors, walls and beams or even entire buildings being craned into place after being manufactured elsewhere.
Overcoming technical and logistical challenges
An airport environment is, of course, very different from a city-centre building site. So how can offsite help? Let’s start – as our team at WSP does for any project – by looking at the sort of objectives aviation projects may hope to achieve and the challenges they face.
A typical airport will want to complete a construction project with as little disruption to passengers and normal business operations as possible. Construction logistics take up a lot of room within the airport, reducing its capacity, which is certainly disruptive. With offsite, materials can be delivered to – and waste taken away from – the manufacturing facility instead, enabling the airport to operate as usual.
Even the act of transporting materials to site is less straightforward at an airport. For an airside project, each delivery must go through the same time-consuming security checks as if it were leaving the country. With this in mind, what would be better – 80 deliveries of materials or one delivery of the finished component?
It’s also worth bearing in mind that some tried and tested approaches to construction just don’t work in an airport environment. For example, if you can’t use cranes because of aircraft taking off and landing, how do you construct a three- or four-storey building? At Stansted airport, our solution was to build the roof at ground level and then jack it up into place. For another airport project we are constructing the entire building offsite a short distance away and transporting it to site on giant trailers.
Offsite is not just a solution to problems though; it is also a gateway to many opportunities. For large-scale, long-term developments on major airports, offsite opens the opportunity to distribute social and economic opportunities to the entire country rather than just the local economy. As with Heathrow Airport, components can be produced where there is a skilled and experienced workforce and transported to site. By integrating design, manufacture, logistics and installation, the benefits of the project are being spread throughout the UK.
Incorporating offsite into the design process
If offsite could help with challenges like these on your aviation project, what do you do next? At this early stage we look at different aspects of projects, using tools we have developed to evaluate how appropriate offsite is for different elements.
It’s important to go through this process early in a project because the findings feed into everything – including the choice of materials and their sizes, weights and tolerances. With these decisions made, we design everything around offsite to maximise the benefits. And, in a controlled factory with robust quality control processes, we can give more consideration to ensuring the working environment is healthier and safer for operatives.
Although working in this way can be a challenge in an industry used to more traditional approaches, many clients I speak to are enthused about offsite. When it’s the right choice for their project, we guide them through a process that helps them unlock offsite’s potential.
WSP Author:
Richard Anderson - Technical Director, WSP
