Building Safety: Does Volumetric Stack Up?

New legislation on building safety has the potential to act as a stimulus for offsite construction but what are the challenges and opportunities ahead? A recent roundtable discussed how volumetric modular methods can help 'fit the Bill'.

When the new Building Safety Bill was published in July, it was outlined by Housing Secretary Robert Jenrick as a key step in an extensive overhaul to building safety legislation that would create “lasting generational change and a clear pathway for the future on how residential buildings should be constructed and maintained.”

Further secondary legislation will likely be needed to tidy up the legislation, and training for construction professionals will be necessary during the transition into a new regulatory landscape. However, in light of the Grenfell Tower disaster, the Bill is a game-changer that gives residents more power to hold builders and developers to account and toughens sanctions against those who threaten their safety. The Bill also highlights a raft of challenges and opportunities for offsite developers. 

Proponents of offsite are well versed in its advantages. When the methodology is optimally executed, these include early client engagement, quality controlled manufacturing of components, BIM enabled 360-degree oversight of the project value chain and a design for manufacture and assembly (DfMA) approach, that enhances efficiencies by using parts designed for ease of production and commonality with other designs.

Offsetting these however, critical gaps in the understanding of offsite on the part of architects, safety specialists and other key players that could hamper its uptake as a ‘safe’ solution. Volumetric modular technology can sometimes be perceived as presenting special challenges because it’s a ‘closed system’ which can mean limited transparency in terms of provenance of parts.

As is the case with many offsite approaches, the gap between the quality and reliability created in the factory and how it translates on-site, can be an issue – particularly when these gaps in application or execution can derail some of that safety and quality.

Implications for architects As the ‘originators’ of buildings, many architects are increasingly aware of the challenges and opportunities offered by volumetric modular. For some, the challenges perhaps loom larger, as they note the new complexities and responsibilities exerted by offsite construction, and in particular volumetric methods. A new compliance burden will need to be taken on by architects, along with other stakeholders in the supply chain, meaning new continuing professional development requirements. Certainly, in the context of volumetric modular, architects need more education, so that they can at least have more useful conversations with manufacturers.

Nigel Ostime, Partner at Hawkins Brown, says it’s critical that when the elements of a building are produced by manufacturers, architects fully understand the process, but also that the manufacturers understand architects’ thinking. “It's really important, says Nigel. “That we bring the industry in general together and its knowledge about all of these issues up to a certain standard, because at the moment different players operate in their own pocket of excellence.”

Hawkins Brown recently established a work stream there on design integration, which is intended to bring architects and manufacturers together. New roles and areas of expertise could also soon emerge to “close the gap” – for example, an MMC advisor or MMC consultant, who might be an architect with knowledge of all categories of MMC, enabling a more informed product selection process for any given project.  

Insurance and risk challenges

Since the Grenfell disaster, new challenges have emerged in terms of insurance. Professionals and developers alike, are increasingly concerned not just about new professional indemnity (PI) claims, but about the potential for claims for buildings from years ago. PI costs have doubled in some cases, putting greater than ever pressure on building providers, and volumetric modular suppliers.

Indeed, the construction industry as a whole has become more risk averse, with key players such as fire safety specialists requiring higher levels of proof in terms of fire safety, detailed evacuation plans and slower product burn rates, as well as cavity barriers, which act as passive fire protection elements to prevent flames and smoke from spreading via walls. 

Fire safety testing

More rigorous testing, some of it specifically targeted at offsite construction and volumetric modular, may be required to provide industry surety. Fire engineers are likely to begin pushing for a new suite of testing that's specific to volumetric, as many are increasingly questioning whether current test methods are fit for purpose.

Testing goes some way to ensuring product safety, but there are, literally, gaps in its effectiveness. For one thing, there is a lack of standardised testing across the industry, which has created confusion, and in some cases, certain elements of the construction don’t have a test at all. For example, cavity barriers can’t be effectively tested in a controlled setting: tests can put a product through its paces, but don’t effectively replicate real world situations. In areas of a volumetric modular design such as intersections, testing falls short. “The challenge that we have is that people are coming to us with very complicated intersections but asking us then to underwrite these solutions with no means of testing,” says Christopher Hall, External Affairs Director for Siderise. 

Perhaps not surprisingly therefore, engagement with testing is patchy. Some manufacturers are engaged in rigorous testing, while some simply rely on published data, employing a fire professional to look at the details of a build to make sure they comply with the building regulations. Another related challenge for the construction industry as it relates to MMC and fire safety, is incorrect installation. An example of this is the addition of fire stopping measures on-site, adding another potential area of risk. “A lot of the manufacturers just provide the modules, and this is where I see a big problem,” says Bob Hill, Technical Consultant at Building Life Plans. “Because then the manufacturers may put the fire stopping in between the modules. Then you've got the cladding manufacturers who come along and put the cladding on, and the module manufacturers don't seem to have a lot of input into that.”

Tom Mason, Associate Director, International Fire Consultants, adds that while the regulations rule against cavities where fire could spread further than 10 or 20 metres, more emphasis should be placed on stopping the fire at the outset. “If a fire has gone into the cavities between modules,” he says. “It generally means something has failed elsewhere in the construction. If it has got through the wall into the cavities between modules, where it could spread around the building, a localised failure has occurred that could lead to a more significant failure.”

The fact remains that many fire safety specialists are currently under-informed about volumetric modular technology and how it performs. A concerted effort to educate them about how volumetric modular should be treated in a fire safety context is key to ensuring industry confidence, as more uptake of modular methods are expected in the years to come. Within this new safety landscape, the better offsite companies look set to thrive by investing in more R&D, investing in education and training, and providing full disclosure about their methods and products.

“It's really important that we bring the industry in general together and its knowledge about all of these issues up to a certain standard, because at the moment different players operate in their own pocket of excellence.” Nigel Ostime, Partner, Hawkins Brown.

The golden thread One of the much heralded benefits of offsite manufacture is that BIMenabled MMC presents an opportunity to create a consistent through-line or ‘golden thread’ of information accessible by all stakeholders involved in the building process. This approach has potential advantages in improving safety outcomes. Once initiated, created, stored and updated, this information is critical in providing continuity across safety measures that have been installed in a factory and those completed on-site.

Adopting this golden thread approach enables architects and other construction stakeholders to stay on the same journey and keep informed about what measures are being implemented and why, at every stage of the process. In the context of the Building Safety Act, BIM-enabled companies who increasingly have end-to-end control of their materials procurement will have a natural advantage. Many in the offsite sector predict this could lead to more volumetric players entering the marketplace – certainly in the medium and high-rise markets.  

Volumetric – pros and cons Within the whole gamut of offsite construction, the wide range of products and approaches available makes testing, safety and compliance in general a challenging prospect. Amid a plethora of product options for offsite construction, volumetric modular, although complex, does have some built-in advantages. One of these is that manufacturers can cover most aspects of the work to a build a module, often employing highly specialised people to do so, across each individual element of the build.

The result, when executed correctly, is a more uniform, unified final product.

In addition, one of the main selling points of volumetric design, is the quality control of the material or the components within a factory setting.

However, it’s often when the module arrives on-site that problems can occur. More industry and supply chain ‘connectivity’ is required, enabling all levels of professional to understand what happens in the factory and to carry that through to site installation.

The potential for improved installation quality in a factory environment is considerable, but it’s also important to ensure that the requirements are clear and that manufacturers aren’t simply relying on products and approaches used in traditional construction – the expecting them to be transferable to an offsite setting.

Manufacturers are capable of bringing volumetric elements to a high level of factory-fitted quality, but that quality loses consistency once the product leaves the factory, with lack of clarity and continuity about execution on-site. If volumetric modular continues to grow rapidly, it’s possible that building control specialists and warranty providers may need to do more to close this gap. There is also an opportunity for the client or the modular manufacturer, or perhaps both, to employ specialist consultants, (that MMC consultant again), to do inspections that ensure correct installation and compliance of modules.  

Learning curves However, training and education are already being undertaken in this area, says Jim Cowell, UK Technical Director, The Elliott Group. “We do have the ability to get people properly trained, to have really robust policy procedures in our factories that can be documented and photographed, and to have continuity between site and factory.”

Clearly, more widespread training standards are required, and arguably it shouldn’t just be up to individual organisations to implement it. Lindsay Richards, Managing Director, The Richards Partnership, adds that training for new kinds of roles will optimise one of the main marketing points of volumetric, which is quality control of the material or the component. “In terms of retraining of individuals, it could be about looking at the equivalent of what we would call a clerk of works, in other words that individual who is trained to understand what has been constructed in the factory and is able to take that forward in relation to a controlled installation on-site.” This can close the problematic gap between the manufacturing environment and on-site installation.  

The way forward

Offsite construction comes in many formats and finding a single way of ensuring its compliance with new safety regulations, guidelines and the Building Safety Bill is no simple matter. But new consultancy/adviser roles with individuals directly connected and experienced with offsite, that includes oversight of safety requirements may help remedy this problem. Meanwhile a more general push to train and educate the wider industry, from architects, to fire safety engineers and installers to embrace more joined-up thinking between design, manufacture and installation onsite is critical.

 “There is a lot of testing that is applicable and can be carried out on buildings, but do we have the test evidence for the smaller bespoke volumetric elements?” Tom Mason, Associate Director, International Fire Consultants.

There are best practice examples of well-designed, safe buildings in both traditional and offsite construction, but undoubtedly, the manufactured element of offsite and volumetric modular in particular has the potential to be standard-setting. “There’s an opportunity for manufacturers to demonstrate how manufactured construction can be more sophisticated than traditional construction,” says Alun Macey, Construction & Innovation Director, Pocket Living. “They operate within a controlled environment with much more stringent processes, with repetition and standard details and testing at the heart of what they do.”

The feeling is that offsite delivery – and by extension volumetric modular technology – has reached a pivotal moment in its acceptance by clients, investors and developers and we are approaching a new frontier of knowledge. “Volumetric offers marvelous opportunities to get it right,” says Siderise’s Christopher Hall. “I think we need to understand what ‘right’ looks like from all perspectives, but its potential is real.” 

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