Modular Buildings Lead the Way for Offsite
posted: 28th Feb 2018
How do manufacturers and installers of volumetric offsite construction ensure sustainability and compliance when the key priority is time? Jackie Maginnis, CEO of the Modular & Portable Building Association, shows how the industry has been leading the way longer than you think.
Offsite construction has become a hot topic in the last few years, and sustainability has been the buzzword of the decade (other than fake news, of course) but there is still an element of ‘catch all‘ with both words.
In 2018, the MPBA will celebrate 80 years of repre- senting modular and portable building manufacturers and installers, innovators in offsite construction. To our members, offsite means simply built in the factory and transported to the destination site, where it will be assembled for final occupation. Build and, in most cases, fit-out is completed in the factory, where a high standard of quality can be achieved.
Manufacturers drive quality in the product through ISO9001 accreditation and BBA approvals. It is due to these high standards that when it comes to thermal bridging and air permeability, tests show that, on average, a factory-built modular or portable building achieves air leakage of between two and three m3 per hour, per m2 at 50 Pascals. There are many more examples of where exemplar quality increases carbon performance, leading to a more sustainable building.
That brings us nicely to sustainability, where volumetric construction has long since led the charge. Back in 2006, as an association we introduced the Department for Communities & Local Government to embodied energy, particularly within the hire and refurbishment markets. When a modular building is constructed as an alternative to traditional methods to be a permanent building, it is built to the same standards required for all construction, with the added benefit that the as-built performance will match the as-designed performance.
The sky is no limit for volumetric construction. The recent 29-floor student accommodation block in Wembley, Apex House, is a superb example of what is possible. With an internal area of 16,000m2, projects like Apex House show the true potential of volumetric construction in the UK, where innovative technology meets great design.
The speed of manufacture and construction is so impressive it can even keep up with the demands of fast-growing markets, such as retail coffee shops. Only with modular construction can a drive-through coffee shop be available and operational on your favourite motorway services, when it wasn’t there a month ago!
It’s the hire and refurbishment market, however, where there is an even greater embodied energy benefit. When a module is manufactured, it could be for a single storey or for a double storey school classroom. As it fits on the back of a lorry, it could start the year as a classroom in York and finish the year as an office in Manchester. A huge benefit of this is the savings made through not having waste and not having two construction projects, two sets of building materials and so on.
If a module is built to a particular set of standards, it maintains those standards throughout its life. Two important additions to the 2013 Building Regulation Part L2 were made to recognise this.
The first addition was the introduction of a Target Emission Rating (TER) adjustment, specifically for use in the construction of a new building from refurbished modules. For example, in a construction to be completed today, to the current Building Regulation standards, if a module manufactured in 2014 was to be utilised, an adjustment factor would be taken into account on calculation within the simple building energy modelling (SBEM) tools to reflect the embodied energy.
The benefit of this addition to the volumetric construction industry and society as a whole is immense. Instead of sending highly efficient, high quality building modules to landfill, they can be reused for a more sustainable future.
The second addition to the Building Regulations was the introduction of the generic Energy Performance Certificate scheme. The scheme is specifically for the hire market, where a distressed purchase is required due to a disaster or accident, or temporary accommodation is required while a larger building is under construction.
The aim of the scheme was to maintain a high level of energy performance within a temporary building while not increasing the cost to the purchaser or delaying the time taken to have an operational building.
It is based on the premise that modular buildings under 1,000m2 only have a specific number of combinations that they can be assembled in, hence where the age of the sub-assemblies (modules) is verified, a generic energy rating can be applied to demonstrate to the purchaser what is typical of the construction they have purchased.
The scheme was created and managed by the MPBA and provided as a service of membership at no additional cost. Our members recognise the importance of sustainability in construction and will continue to lead from the front with innovation, technology and communication.