Modular Construction: The Future for Housing?

Liz Brown, Associate at Pozzoni Architecture, considers whether modular construction can provide a solution for the UK housing crisis.

Our broken housing market is one of the greatest barriers to progress in Britain today.

“Whether buying or renting, the fact is, that housing is increasingly unaffordable – particularly for ordinary working class people who are struggling to get by.”

DCLG Fixing our broken housing market – foreword by PM Theresa May

For me, the key factor when considering modular construction is the cost per unit. Currently, it is no cheaper than traditional building methods. To even match the cost per unit of traditional building methods, a minimum number of modules needs to be ordered and the modules need to have a high level of uniformity to allow mass production. What’s more, the client and design team need to consider modular construction from the inception of a project, therefore potentially limiting the cut and thrust of traditional building procurement routes and the potential value engineering process that this allows.

A key restriction is transporting modular units to a site. An early site visit with the preferred modular construction company is required to determine any access limitations and the maximum unit size (both width and depth) that can be delivered. This will then form the basis of the design, with the principal being the same for all buildings, from individual houses to large-scale apartment blocks. For Premier Modular, who recently visited the Pozzoni offices to present their ‘standard bespoke system’ for modular construction, the widest unit size is 4.5 m (14.8 ft) and the longest is 19 m (62.3 ft), with a maximum of 25 floors.

The key benefits of modular construction is speed, with whole buildings able to be delivered in a matter of days, and the quality of workmanship (including full internal fit-outs) that can be achieved. If the construction programme is carefully considered (including those pesky service connections that can take so very, very long) then real savings in time and contractors’ ‘prelims’ can off-set the higher build costs. For highly restrictive inner-city sites or buildings that needed to be finished yesterday, then modular is the obvious choice. For clients who want high-quality buildings that minimise ongoing maintenance costs then factory finished quality control becomes desirable.

And for the architect, modular construction is surprisingly innovative and adaptive. Yes, to achieve lean manufacturing techniques, there is the need for uniformity and mass production. Yes, this does mean the components are boxes on a back of a lorry that are stacked on site. However, there are a wide range of design options that go beyond a city of portacabins, which can include:

  • Folding-out parts: the module has a hinged roof that can be erected on site and cladding panels installed to create the additional height of wall
  • Variations: the modules are steel framed boxes, therefore fenestration and other apertures can be varied on ‘standard’ modules without stopping the production line
  • Self-support: the steel frame on the outside of the module is self-supporting therefore internal walls, within reason, can be removed at a later date
  • Any combination of external materials can be used
  • High environmental performance standards

Obviously, the design team needs to plan and think about the project in a different way to achieve the best result for its clients in what could be considered a game of Jenga.Actually, the joint client, design and construction team needs to plan and think about the project in a different way to allow the best results in design quality (both external appearance in relationship to site context and internal fit-out) and programme efficiency (service connections and below ground works being crucial). In my opinion, this, married with the higher build cost and the need for minimum unit numbers, often stops modular construction becoming a solution for the housing crisis at the moment in time.

For me, this is the real crux of the matter. The British construction industry will need to change if the traditional construction workforce is reduced either by the more immediate limitations of Brexit or the more long-term issue of recruiting younger generations into the begrimed and potentially dangerous (high rates of occupational ill health in either the short or long term) world of site.

Will younger generations prefer the sanitised and indoor world of the factory floor, therefore resulting in modular construction becoming the more affordable option? Could this also potentially widen the demographics (modern day construction is still dominated by a white male workforce) and therefore solve the skills ‘time bomb’, potentially allowing local production lines to solve local housing needs providing an improved economic climate for the local area?

For this we need to move away from the concept that a house is bricks and mortar, and to learn to think about the construction process in a different way.