While the use of off-site construction is growing steadily, the demand for innovation is bringing pressure for greater integration and certification. Charles Westbrook, R&D director of Mtech Consult, reports

Off-site construction (OSC) technology has been here for more than 10 years, and has become a recognised alternative construction method for a wide range of building applications. It is becoming a mainstream method of building throughout the UK and is set to further increase its market share over the next few years, with growth projected to reach double percentage figures.

However, it would be unwise to become complacent. There is now considerable pressure from the government, developers and the operators to improve the reliability, performance and effectiveness of the off-site delivered product. This is underpinned by the increase in performance validation requirements and the demands of lenders and funders.

Where are we now?

The European Organisation for Technical Approvals (EOTA) has launched a range of European Technical Approval Guidelines (ETAGs) covering metal frame kits (0025) and concrete frame building kits (0024) – to complement the already developed ETAG 007 covering timber frame building kits. We hope to see a similar ETAG for prefabricated building units (volumetric modular) in due course. These new and proposed standards define a route for compliance with the Construction Products Directive, a set of common guidelines for the assessment of building systems. This gives EOTA members such as the British Board of Agrément (BBA) and BRE common standards for the assessment of building systems.

These standards will ensure greater consistency, both between accreditation organisations and in performance requirements between each manufacturer. Developers and system users will have, perhaps for the first time, a more reliable measure of the relative performance of the different manufacturers’ systems, and will be able to assess more accurately the ever increasing range of non-UK supplied OSC solutions.

Although these standards are yet to make their mark on the UK industry, the fact that they give manufacturers a direct route to CE marking of their product should mean that third party endorsements to ETAGs will allow UK manufacturers unrestricted access to European markets, with massive export potential.

In a similar vein, BRE has launched a new standard – LPS 2020 – for factory-made housing which will cover all forms of off-site manufactured housing technology. This standard, which is one of the LPS suite of standards set by the insurance industry, attempts to establish common standards for the supply industry for areas such as flood protection, repair and refurbishment in the event of fire. While it will take some time to become mainstream, it has the full backing of the insurance industry via the Association of British Insurers, the Council of Mortgage Lenders and UK government.

BRE proposes to offer third party certification to system manufacturers so they can claim conformity with the LPS performance requirements. While this may cause some confusion with the existing third party product approval systems, such as the BBA Agrément Certificate or BRE certification, it should only help to reinforce off-site technology as a serious alternative to traditional forms of construction.

Benefits of certification

What certainty is there that UK technology can be substituted with another manufacturer’s system imported from elsewhere in europe?

Even with the move towards greater harmonisation of testing and certification, there is still a long way to go to reach complete integration of products.

If we design a building based on off-site technology from a manufacturer in the UK, what certainty is there that this technology can be substituted with another manufacturer’s system produced elsewhere in Europe?

It may be that the industry does now need to adopt some form of uniformity and commonality of product to help it move to a higher plane, where true mass production of building systems is feasible. Certification systems could hold the key to this.

The big question for the industry, and one that Mtech has been wrestling with for some time, is how to get to this idealised state? Effectively imposing standards on an industry that has grown up with few regulations or guidelines is likely to take some time.

Some in the OSC industry see certification as a necessary evil; others believe it will inhibit the development or introduction of new techniques.

The challenge is to make the certification process better value for money, more focused on customer service and more output driven, without compromising the integrity of the certificate itself.

The way ahead

And there are encouraging signs. Mtech has been involved in the establishment of Buildoffsite (www.buildoffsite.com), to promote the widespread use of off-site construction technology. With UK government support, this manufacturer and client-led body is already identifying ways to create harmonised methods of construction and standard interface details, all intended to help the supply chain mature into a sophisticated and effective manufacturing industry. The focus here is on standardisation of the process – not just the product or system.

The real issue is not which organisation leads the battle on standardisation within the OSC industry. The key is to encourage the relevant certification bodies to work together to improve the integrity of the certificates, while providing ever improving value for money and enhanced service so that the OSC supply chain embraces these protocols more readily.