Modern Methods of Construction - Disruption to Traditional Methods?

Terry Stocks
It has been said if we were able to take an ancient Egyptian into a current day manufacturing facility they would be totally confused by the processes going on around them. Take them onto a construction site and they would be able to pick things up almost straight away!

If we also consider that material science and technical services knowledge is moving on a pace, but the way we contract, programme and build our assets is largely static, it is not surprising we have a construction sector that lags behind the productivity of other industries.  We are reliant on individual performance and skills sets aligned to key trades. Construction has a tarnished and traditional ‘muck and boots’ image and with an ageing workforce, that is leaving the industry quicker than they can be replaced and a reliance on a non-UK workforce, we are heading for a problem. A problem of rising prices, non-delivery of key social and economic infrastructure and increased quality issues with delivered projects.

Modern Methods of Construction (MMC) is a concept that could help the industry disrupt itself and transform to meet the challenges it faces and the demands of an increasingly digital world. It can also help meet the changing skill sets of our young people and the changing employment patterns required to maximise opportunity in a modern world.  MMC is the generic title covering a number of ‘Design for Manufacture’ and ‘Build Off Site’ approaches, comprising - Volumetric design, Panelised Design, Component Design and Standard Platform Design. No one will provide a complete answer to the industry challenges and are arguably not all disruptive in terms of changing the way engagement between clients, supply chains and contractors are currently undertaken. However, used appropriately to suit site, programme and policy outcomes and requirements they will unlock a new era for the construction industry.  Traditional construction will still have a part to play, but in a much more sustainable and focused way. For MMC to work it must have client support and a supply chain willing to modernise and adapt to new roles and ways of working. Key Government clients must already plan their projects with a ‘presumption in favour of offsite’. The term ‘Designed for Manufacture’ is key. The MMC approaches need to be inherent in our thinking when planning, designing and building our assets. This is key to gaining the efficiencies and performance these approaches can deliver.  

So what is the MMC ‘tool kit’? 

Volumetric – This is where a building or facility is designed as a series of ‘volumes’ with walls, floors and ceilings / roofs manufactured as complete spaces in factories, ready for stacking and connection on site. The advantage here is that the units are built in a factory environment in parallel to the on-site connections and ground works being completed, saving programme time and on-site labour force. The disadvantage of this approach can be the barrier to entry right at the start. Significant investment is required to set up a factory facility and ramp up production, meaning there is a significant lag between capital investment and revenue generation. Another key disadvantage is one of transport logistics, with the units tending to be overdesigned to sustain the lifting stresses and transit forces. Weather proofing prior to making totally water tight on site is also critical. Another noted downside is that given they are ‘volumes of space’ being transported, results in a requirement for numerous deliveries to complete a project.

Panelised Design – The panelised option is an effective way of using factory manufactured elements while better optimising delivery logistics and also support speed of erection. The panels can be configured to combine external finish, insulation, internal finish, windows etc. in a single panel. They can be concrete, composites or a mixture. Internal walls would be processed in a similar way. The panels are stacked and fixed generally without the need of external access scaffold and are manufactured in parallel with ground works and lead up services installations. Internal building services are installed utilising traditional methods or can utilise pre-fabricated services that are craned into place within service ducts, or designed as ‘service looms’ that are installed in-situ. The panelised system has some advantageous over the volumetric approach in flexibility of build, but of course is less complete when erected requiring significantly more on site finishing work at site level. Services can be cast into the panels but can create issues with commissioning and operation in the longer term.

Component Design – This is where standard components, beams, columns, floor plates etc. are designed along with their fixings to be shipped to site as a kit of parts ready for onsite assembly. A component design approach is best suited to single use high volume products, such as housing etc. Their advantage is that volume can drive down component cost and delivery logistics are optimised. External and internal finishes and services can be a mix of traditional and prefabricated to best suit the design. 

Platform Design – This takes the concept of component design and improves upon it. It is probably the nearest, in process terms, to large scale manufacture, in that it deploys standard shared platforms across a number of asset types. This is similar to the shared chassis programmes deployed in the automotive industry across manufactures and models. A study of asset types designed and built independently and bespoke to clients has been undertaken. The study concluded that given the freedom of design choice, all the schemes had very close grid layouts and floor to floor heights. This is unsurprising as design factors are built around maximising light penetration into buildings, dictating room depths and optimising room heights to maximise the number of floors in a development. Therefore, it is possible to design a limited number of sub structure platforms that could service a majority of our social infrastructure needs.

The MMC approaches need to be inherent in our thinking when planning, designing and building our assets. This is key to gaining the efficiencies and performance these approaches can deliver.

The Platform approach to design, like the component design concept requires volume to make it commercially viable but does have the ability to address current capacity and skills issues facing the construction industry more than any other. It is however one of the hardest to make work given the current contractual landscape, commercial models and its potentially truly disruptive approach. In terms of the current supply chains ability to deliver, it is arguably one of the simplest approaches.  

The common theme across all the schemes is one of skill optimisation and speed of construction. Traditional trade experts such as electricians, plumbers, HVAC services engineers etc. are used sparingly to sign off the systems in terms of safety, operational efficiency and quality. The processes lead to a very systemised process of manufacture and assembly leading to increased employment opportunities to a wider community, with both full time and flexible employment. The service industry we all increasingly use to buy our coffee and sandwiches amongst many other things, provides a wide employment opportunity. However, it’s not for everyone and construction through the MMC approaches can provide alternative careers for this group of employees. Matching warm and dry places to work if factory based or travel and outdoors if site based. People are different and want different things. MMC taps into this wide employment pool providing sustainable futures for individuals and the wider industry.  Standard approaches to building does not mean ‘boring buildings’ either. All the processes included within the MMC approach allow for standard approaches to bespoke building shapes, differing façade treatments etc. Designers will always design and the environment where a building sits and the way it interfaces with its users will always be unique.

Component and Standard Platform

Component and Standard Platform approaches lend themselves better to harnessing a wide manufacturing and fabrication workforce across the UK, with co-ordinated deliveries arriving to site ‘just in time’. This approach also allows local site hub facilities to be deployed acting as final stage assembly plants, logistics management etc. further optimising site component / sub assembly delivery to the site work face.  

Volumetric, Panelised and Component processes can generally be deployed under traditional contract forms. However, a move to a shared Platform approach will require different contract approaches and risk alignment.

Volumetric and Panelised approaches are easily deployed on short run client programmes but are less deployable across industry. Component design concepts straddle the cross industry divide between Volumetric, Panelised systems and the Platform approach, but are ostensibly single asset type focused, such as housing. Platform approaches require a cross client commitment to make commercially viable. They need a sustained level of purchase to allow the specialist supply chain to ‘gear up’ and manufacture on spec.

In terms of the current supply chains ability to deliver, it is arguably one of the simplest approaches.  

It’s clear a paradigm shift in our approaches to construction is required if we are to deliver the social and economic infrastructure we require. We can move a way towards that change through a greater commitment to Design for Manufacture and Off-Site approaches. However, are clients and supply chains able to adopt the more radical approaches?  Is there an over guarded approach to Intellectual Property, where in reality, as has been highlighted, a high proportion of the sub structure elements are within close tolerances. A different approach to risk apportionment and management could also support a change of culture within construction and support the drive for improved productivity, efficiency and quality.  

Is it possible for clients, developers, portfolio asset owners to work together to ask for standard designs from their supply chains? If this can be made a reality through the support of experts such as Faithful+Gould and Bryden Wood, we can, as an industry move forward in a sustainable way that mitigates the issues brought about through a growing industry skills shortage and budget challenges.  

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