Paul Gandy FCIOB, BSc (hons) MBA, vice president of CIOB and assuming the role of president in June 2025, discusses the use of MMC in disaster relief
Whilst the data shows considerable variation over the very short term, it seems to be unquestionable that over the medium term – say the past 50 years – there has been a large increase in the number of natural disasters. The World Meteorological Organisation reported in 2019 that there had been a fivefold increase over the past five decades. The Food and Agriculture Organization of the UN reported in 2023 that disaster events had increased from 100 per year in the 1970s to around 400 events per year, worldwide, over the last twenty years.
It is the case that many smaller events that took place earlier in the period will not have been captured in the data, and that this will lead to some distortion and potential exaggeration; nevertheless, there is clearly a challenge. Climate change is leading to increased flood events, and we are seeing regular wildfire crises.
Why is there a need for climate-response MMC?
Putting aside climate-driven disasters, earthquake and tsunami events will always be with us, and sadly, people will continue to be displaced by conflict. It is also the case that the human impact of these events is compounded by the increasing global population, both in terms of absolute numbers and in terms of density.
It is critical that we can respond to these disasters quickly and effectively. People who have lost their homes and whose communities have been destroyed need the basics of shelter, security, and community to be replaced extremely quickly. In my view, this is not the same as the longer-term challenge of the permanent replacement of the homes and assets. The challenges and needs facing those addressing the immediate crisis are different, time is of the essence, and this is where Modern Methods of Construction (MMC), including pre-fabrication, comes into its own.
Let’s look at the challenges:
Availability and storage
Time is of the essence. Therefore, the implication is that there needs to be a stock of accommodation ready for immediate despatch. Putting aside the challenges of funding and international co-operation and coordination that are central to any truly effective response capability, this raises issues of demands for storage space, durability in storage and the like.
Transport
Having established a suitable stock of accommodation, the next challenge is that of transport – the units need to be readily and efficiently transported: clearly, weight is an issue when considering road or air transport, albeit less of a problem with seaborne transport. Equally important is the issue of volume – “transporting air” is not efficient.
Ease of assembly
It is likely, (and maybe desirable for reasons of availability, ownership, and community self-esteem), that much of the erection will be carried out by local people, those most impacted by the issue. The system needs to reflect this. Component handling, assembly techniques, and the like must be simplified and locally deliverable without too much in the way of specialised equipment or skills.
Speed
Erection times are critical. Not just in terms of the superstructure element of the building, but also its requirements in terms of its foundations and support infrastructure.
Re-use
It is surely desirable that any solution can be readily dismantled and put back into storage for future re-use. This dictates elements of the solution.
Performance
Weather conditions vary widely and can be extreme, especially in instances where the accommodation remains in place for the medium term, maybe through several seasons. Issues of thermal performance and water tightness become critical once the initial crisis has passed.
Scalable and adaptable
Demands will be varied, family unit sizes differ, and there will be a need for accommodation beyond temporary homes, for instance, medical centres, food provision, dining facilities, and so on. Ideally, the basic solution should be a single one that is scalable and adaptable.
Having considered the needs outlined above, we also need to reflect on what we are not trying to achieve – this accommodation is not intended to be a long-term solution, that is a different challenge and one where, without doubt, MMC should play an important part.
However, the immediate response can, and must, compromise in areas such as:
Aesthetics
Functionality and economy are the key issues; the appearance is, at the very least, secondary to these. This attribute is beneficial when using industrialised and standardised solutions.
Space and scale
The priority is shelter and security. Realistically constructed space will be at a premium, and there will be a compromise involved when it comes to the size of accommodation units. Again, the inevitability of this compromise is helpful when pre-fabricating units in a factory environment.
Long term durability
Whilst it is desirable, maybe essential, that this accommodation can be used multiple times, it should not be designed and fabricated for the fifty-plus years of usable life appropriate to permanent accommodation.
So, what does this mean?
Weight
This does need to be minimised- concrete is a great product, it is very durable, flexible, has high mass, which helps with temperature control and can be fast on site. It has proven itself as a material for MMC solutions in areas such as custodial facilities, and, when properly designed and executed, as a solution for residential accommodation. However, it is very high mass and therefore is hard to transport and, in particular, hard to handle on site without the right heavy equipment, which may not be readily available in quantity at the site of the disaster.
Volume
Volumetric accommodation, whilst it can satisfy many needs such as speed of erection, ease of assembly on site and “completeness” of the unit, is problematic in terms of storage and transport. Whilst volumetric solutions have been applied in the past, for instance with container-based accommodation, you are essentially transporting boxes of air (albeit they can be used to store and transport other components required for the completion of the facilities). It will also require heavy plant to handle it at the destination site. It demands large amounts of road transport and effectively excludes air transport.
In my view, this leads us to panelised or component-based solutions. The basics should include:
Panels or components that are designed around standardised module dimensions allow some “scalability”. The connections between components should be “dry”, which means bolt or clip together using seals to achieve weather tightness rather than in-situ products.
The components must be lightweight to ease transport and erection and, importantly, to eliminate the need for complex in-situ foundations. Ideally, the “foundations” should simply be base units, such as pads or frames, that are laid upon levelled ground.
The panels need to have high thermal performance and should provide the necessary weatherproof external skin. Composite construction, so commonly used across the construction industry, readily satisfies these demands.
One of the challenges when seeking to erect a large number of accommodation units very quickly, and in a region that has suffered from considerable damage and disruption, will be the infrastructure for water, power and waste. Solar panels could be incorporated into roof units, supplying lighting and minimal power outlets that are pre-installed into the accommodation’s components. Rainwater collection could also be incorporated into the design. Waste management is a major challenge; communal facilities are undesirable beyond the initial response period, so facilities for in-unit facilities and a future connection to a waste infrastructure should be incorporated.
There is nothing new in this; many have reached the same conclusions in the past, and indeed, a quick search of the internet will reveal some apparently good solutions that have already been implemented.
The challenge, which in many ways reflects that encountered when seeking to apply MMC to permanent housing, is one of establishing a predictable demand, rather than trying to respond in a knee-jerk manner to short-term emergencies. With this demand established, proper investment in the optimum solutions – initially the design, but subsequently the advanced manufacturing – could be achieved. There are many clever people out there who can (and probably in parts already have done) resolve the technical challenges.
“This leads me to conclude that the real problem isn’t a technical one – we have the experience and expertise to deal with that – it’s one of international co-operation and intent.”
Of course, once the initial crisis of re-homing has passed, there remains the problem of rebuilding for the long term. Without doubt, MMC, including modular construction, should have a major role to play when it comes to the permanent reconstruction.
However, whilst speed is important when it comes to reconstruction of homes and the re-establishment of communities, issues of durability, functionality, design of community and aesthetics become critical as well, if these “new” communities are to be successful and sustainable. This almost certainly leads to different solutions from those that respond to the short-term crisis.
By its very nature, addressing the longer-term challenge means more time to plan and respond. Manufacturing facilities can be locally established, thus reducing the issues of transport referred to earlier. There will be time to install proper substructures, which opens up the possibility of concrete solutions, and/or taller construction. It also means that volumetric solutions become more viable.
The solutions for this permanent reconstruction shouldn’t really be any different to those needed to address the housing crisis at home here in the UK. For certain, the aesthetics, the climatic environment and no doubt other factors vary from region to region and country to country, but surely the essential challenges and therefore solutions are pretty consistent?
What is for certain is that for the necessary investment in design and manufacturing facilities to take place, there needs to be confidence in long-term demand. Without this, solutions can’t be optimised, and unit costs can’t be driven down. Witness the number of volumetric manufacturer failures in the UK over the past few years.
I digress – I set out to consider the challenge of emergency response to climate-driven disaster and the place of MMC in responding to that challenge. MMC is not just part of the response. It is central to, indeed essential to, addressing that challenge. We have the technical ability, but do we have the international intent? That’s probably not a question that a builder can answer.
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