In early 2019, the Ministry of Housing, Communities and Local Government's Joint Industry Working Group on Modern Methods of Construction (MMC), produced the MMC definitions framework.
The framework introduced the sector to 7 categories of MMC, as follows:
-
Cat 1 - Pre-manufactured 3D primary structural systems which include modular pods which form the structure of the building and can range from basic structural pods to fully internally and externally finished structural pods.
- Cat 2 - Pre-manufactured 2D primary structural systems which include structural 'flat packs' comprising floor, roof and wall structures which are made off-site and pieced together on-site to form the final 3D structure.
- Cat 3 – Pre-manufactured components which are non-systemised primary structures which include the off-site production of structural components such as superstructure load bearing beams, columns, walls and staircases as well as substructure pile caps and ring beams.
- Cat 4 – Additive manufacturing of structure and non-structural components which include the 3D printing of structural walls from concrete, or the 3D printing non-structural elements of buildings.
- Cat 5 – Pre-manufactured non-structural assemblies and sub-assemblies which include non-structural kitchen and bathroom pods or non-structural parts such as roofing finishes and non-structural walls.
- Cat 6 – Traditional building product led site labour reductions and/or productivity improvements which includes traditional single built building products which are designed to reduce labour or increase productivity, such as pre-cut configurations of materials or those materials designed and manufactured with easy joining.
- Cat 7 – Site process led site labour reduction or productivity or assurance improvements which include the use of site worker augmentation, the use of exoskeletons, GPS, wearable technology, Artificial Intelligence (AI) and Augmented Reality (AR).
While this definition framework has helped the industry deduce what exactly amounts to MMC, there has been a tendency to focus on cats 1 and 2 and avoid encouragement in the use of cat 7.
This can be seen when you look at MMC focused frameworks such as LHC (which focusses on 4 workstreams including: dimensional modular systems, panelised systems, main contractors and groundworks) and Procurement for Housing (which has both a cat 1 and a cat 2 framework, but no frameworks for delivering cat 7).
This can also be seen when you review the PAS 8700 which "primarily covers pre-manufactured or off-site constructed forms of MMC" as opposed to the site process led productivity improvements, which are heralded by cat 7.
While the focus on modular (and cats 1 and 2 specifically) can be understood, especially in the context of PAS 8700, due to the complexity and specialism needed to embark on modular programmes, there appears to be a tendency to overlook cat 7 which could bring many benefits and hold fewer drawbacks. Cat 7 would likely be easier to implement, with less of the usual criticisms of modular (insurers scepticism, lack of reliable supply chain, issues with planning restrictions etc.).
In order to consider whether focus should be given to cat 7, it is important to view and consider the benefits this form of MMC has in practice.
Looking over the pond at the US construction industry, ABB and Cosmic have employed AI powered robots to rebuild homes in the Los Angeles area, which they state has cut build time by 70% and costs by 30% when compared to conventional methods. This demonstrates that a focus on cat 7 can yield the same benefits of the other categories of MMC (namely improved cost and speed).
Turning our attention back to the domestic construction industry, BAM has employed cat 7 on a number of projects with success. Notably they employed a robotic dog named Spot, which was fitted with built in laser scanners, to work on a remote construction site in Shetland.
Spot was able to collect data and compile records over a large area whilst being controlled remotely, which was especially useful on this site given its isolated location and harsh weather. This likely saved both time and costs, as Spot was likely more efficient and more easily able to traverse the difficult terrain. Consequently, there was no delay or expense in waiting for an expert to travel to the remote site to carry out this work manually.
AR and Virtual Reality (VR) also have great applicability in the construction sector, despite its somewhat limited uptake, creating the ability to visually spot likely defects and deficiencies in a design by viewing the plans in 3D virtually, or by comparing the as built work with the design in real-time using AR. This therefore reduces the cost and time required to remedy the defects at a later date.
Using both AR and VR can mean that dangerous infrastructure sites can be safely inspected and reviewed, a technique BAM employed whilst working on the King Edward Bridge in Newcastle. This not only protected workers from potentially hazardous environments but also reduced the need for on-site visits and accelerated the planning process, likely reducing both the cost and duration of the project.
Even from the small selection of use cases for cat 7, it is plain to see that this type of modernisation (moving away from a modular focus) has the ability to reduce costs and speed up construction. All that, without the common draw backs of modular construction, such as delays with planning permission, supply chain difficulties, storage and transport issues and often difficulties obtaining insurance.
Considering the conclusions reached above, the answer to the question 'Is it Modular over Modern' seems to be yes, but the reasoning for why practices such as those provided for in cat 7 aren't favoured on par with those of cat 1 and 2, seems nowhere to be found, resulting in a missing cat and, on the whole, an owner who isn't out searching for it.
