We all know that the construction industry has issues, and frequently these boil down to us believing things should be delivered faster and cheaper. Progress, according to widely accepted thinking, lies in building more off site. In other words, modular is the answer.
But I would argue we should stop automatically reaching for this response and ask instead, what is the question?
We need to begin by being honest about what modular really is and how it is already used. Let’s start with the phrase “modern methods of construction”. In reality, prefabrication is over 100 years old.
The first design for a house to manufacture was Le Corbusier’s Dom-Ino House, conceived in 1914. Then in 1919 the UK government’s Homes for Heroes programme sought to build 500,000 modular homes for WW1 veterans – albeit 200,000 were actually delivered through the programme.
So, the term “modern methods” is neither accurate nor helpful. That is not to say modular has no place in the future. It is likely to be an essential element in how we deliver better buildings in better ways.
Undoubtedly 100% prefabrication can be the ideal – under Project SLAM Lendlease delivered 10,000 new homes for single service personnel. We managed this in just 10 years, thanks to offsite manufacturing.
To achieve this kind of efficiency modular needs to be in the plan at the design stage, with the supply chain involved from day one. These are the firms designing and producing modular elements, so if they are not involved at the earliest stage, introducing modular to the scheme will mean you have to back-solve. This means designing it twice – cancelling out the time – and cost-saving benefits of using modular in the first place.
Yet even if modular is properly considered at the inception of a project, there can still be compelling reasons for building on site. For a start, the risk of involving the supply chain in prefabrication needs to be assessed when considering the 12-year liability period.
Modular is often said to be safer and of course it means fewer people on site and at height and fewer falls of materials. But when people make the assertion that modular is safer overall, do they have an overview of safety in that factory?
You also have to factor in that with modular, if something does go wrong, it can be more severe, because you are dealing with larger, heavier components. You are still building, it’s just that the building blocks are bigger. So, when assessing whether modular is the right solution for a project, you have to think about health and safety in a different way.
Equally, the argument that modular is quicker and cheaper, while often true, and especially so with programmes with a high degree of repeatability, this is not the case where there is no economy of scale. We need to consider the whole lifecycle before we decide that for a particular project offsite is best.
There are also other ways to build more efficiently, such as creating factory conditions on site. It’s important that we don’t get so focused on modular that we ignore other methods that may be more effective depending on the case.
We need to make intelligent assessments in the round about when and how to build on site or off site.
At the International Quarter London, Stratford, working with London and Continental Railways, we have built what are essentially component buildings, but we have looked at the project in whole-life terms and identified that it makes sense to build on site and in the factory.
For instance, we poured concrete in situ because the carbon emissions saved by eliminating the need to transport concrete were significant enough to make this the best approach overall. The facades, meanwhile, are unitised. IQL buildings have closed cavity façades, with integral blinds and triple glazing. This high level of sophistication, as well as the heights involved, required a quality of installation that would have been difficult to achieve on site.
So, while modular is undoubtedly part of the answer, the questions are multiple, complex and unequal. As a result, modular is only one of a mix of many answers.