In this Monologue, Debbie McCreath, Senior Architect at JTP, discusses the rising use of Modern Methods of Construction (MMC) in the architectural and built industry world as we witness an increase in modular construction to deliver buildings in a more efficient and effective way.
Modular buildings are not a hypothetical fancy. Off-site construction – in which a building’s components or modules are constructed in a factory setting before being transported to site for assembly – has been happening around the world for some time now. But in recent times, it has been attracting a wave of interest and investment on the back of ambitions in the technological and economic environment. And the UK market is really starting to embrace these modern methods.
Shifting aspects of building activity away from traditional on-site processes to an off-site manufacturing-style production has a great number of benefits, as we have experienced on our recently completed student housing and residential apartment project Lewisham Exchange for Tide Construction, where JTP were involved from concept to completion. The project comprises two buildings at twenty and 35 storeys, providing 67 affordable apartments and 758 premium student residences with associated communal spaces for student activities and building management. It is currently the world’s tallest modular student accommodation building in the world.
The construction technique of the residential and student buildings is 3D volumetric off-site modular construction. The modules are constructed from steel frame panels and concrete floor slabs within a factory environment and transported to site ready for installation. One of the many benefits of using off-site construction is efficiency. The fabrication process and factory work can progress in parallel with early site works resulting in an accelerated construction programme, greatly reducing the overall build schedule compared to traditional construction.
The basement and lower levels are traditional concrete construction along with the stair and lift cores. Once they are complete the modules can then be installed on site. Cladding the building can commence once the modules reach a minimum height and progress in tandem with the module erection sequence. A rainscreen cladding and Mechslip brick system was used, helping reduce installation times and associated costs. Constructing the modules in a controlled, factory environment has many benefits, including:
- Modules are completed to a high-quality and standard of finish, including all fittings, fitments, painting and tiling.
- Construction exceeds industry standards in terms of acoustics and air tightness.
- Typically, 60% less staff are required on-site, especially wet trades, meaning less reliance on skilled labour and providing increased levels of health and safety with a reduced number of people working at height.
- Minimal disruption due to weather conditions.
- Quality checks within the factory minimise snagging and defects on site.
- Sustainability – with a reduction in site waste by approximately 80%. Less noise, dust and construction traffic lead to lower carbon emissions.
- Less on-site disruption to local environment and neighbouring communities.
- Less site traffic makes the construction system suitable for tight urban sites which has been demonstrated on Lewisham Exchange.
- Earlier return on investment as investors are able to access revenue streams faster.
- Earlier access to housing for prospective residents.
At Lewisham Exchange, 1,251 modules were installed at a rate of approximately 55 modules each week. This equates to around two storeys per week. It is a rapid construction process. The innovative construction techniques and coordinated build sequence enabled Lewisham Exchange to be completed in an impressive 91 weeks, with the building reaching practical completion in August 2021 with students moved in in early September 2021.
JTP is also currently working with BoKlok to deliver 173 pioneering new homes on land at Airport Road, Bristol. Achieved through modern methods of construction (MMC) which uses timber-frame modular technology to produce schemes of up to four storeys, the buildings comprise separate modules, all of which are fabricated off-site in a factory, and then transported to the building site for assembly. About 80% of the house is built off-site while the actual on-site construction takes up to four weeks.
While the popularity of modular construction has fluctuated in the UK, several factors lead us to believe that the current renewed interest in modular construction may have staying power. The maturing of digital tools has drastically changed the modular construction proposition. The design of the different modules, the coordination of the processes within the construction facility, and the optimisation of the logistics of just-in-time delivery on-site are just some of the enhancements that are changing the modular proposition. Additionally, some companies are very successfully challenging the preconceptions of prefab housing as low-quality, prompting a change in consumer perceptions.
At a time when many cities face serious shortages of affordable housing, I really believe that, in order to address the UK’s capacity issue, the modular proposition will play a key role in pushing the industry forward. This coupled with the many environmental and social benefits of MMC will help the construction industry in meeting sustainability targets and work towards a net-zero future in parallel with net-zero buildings.
