Has the DfMA revolution begun?
The construction industry is evolving.
We all acknowledge that many of the technologies that are adopted in constructing our buildings for the 21st century are based on the same principles as the Egyptians used to build the pyramids. Obviously there have been (and continue to be) significant advancements in the way buildings are constructed on site. And construction sites are now generally very well managed spaces, where the safety of workers, visitors and the public is of paramount importance. But the construction process, the programme of works and quality of the end product is still heavily influenced by the weather and the skill base of the workforce.
It is widely recognised that the number of skilled workers reduced during the recession; and as the market has recovered, a skills vacuum has been created. There are simply not enough skilled trades and specialist subcontractors. This is driving up prices, whilst impacting on quality and programme. The market conditions now exist for off-site manufacture of major building components to be a viable solution. This also provides us with an opportunity to introduce another acronym into the construction industry vernacular. DfMA (Design for Manufacture and Assembly) is the commonly used term to define this process.
At Curtins, we are strong advocates of DfMA, with our involvement in this sector dating back to the 1990’s, when many of the PFI prisons across the UK were manufactured off-site. Whilst we have been working on off-site manufactured projects throughout the intervening decades, it has never really become a part of mainstream construction, in the same way it has on the continent. The technological advancements in IT and the advent of BIM is tailor made to support off-site manufacture. It allows more of the design and detailing to be automated, which reduces errors and increases output and productivity.
Our work on a 1,000 bed student accommodation scheme in the North East provides a live example of how DfMA is being adopted in the current market (pictured above, courtesy of Interserve).
The design, detailing and manufacture of the finished precast concrete structure has involved a large number of consultants and specialist suppliers. As the design and detailing has been completed, the precast concrete panels have quality checked and released for manufacture, in line with the construction programme. We worked closely with the specialist installers to ensure that each element was appropriately tagged within the digital model, allowing reports to be generated that tracked progress against the programme; meaning panels could be delivered to site precisely when they were due for installation. This truly collaborative approach has achieved improvements in performance and output, when compared to similar projects not undertaken in a digital environment.
Whilst the various initiatives we have put in place were primarily aimed at delivering collaboration and efficiencies during the design and construction elements of the project, the detailed 3D model comprises intelligent attributes that can be used to support the management of the building throughout its life cycle. Indeed, the superstructure model, which was used as the fabrication model for purposes of manufacture and installation, is also embedded within the final model for the whole building. The final construction model, incorporating all the intelligent attributes can be used by the FM team as part of any responsive or planned maintenance of the building. The model incorporates accurate and detailed information on the position of all embedded elements within the concrete walls. All conduits and associated cables and fittings are identified allowing any replacement works to be easily planned. Likewise, any significant structural interventions that may be required during the future life of the building can be accurately planned to avoid any clashes with embedded elements within the walls and floors. Where new openings are to be formed in wall panels, these can be positioned to best suit the individual panels. Moreover, the costs of these interventions can be more accurately defined, given the inherent knowledge of the concrete panels contained within the model.
As this project progresses towards a successful conclusion, we are seeing more projects adopting DfMA as the preferred solution. The £89 million development of the Sir William Henry Bragg Building for the University of Leeds is currently on site and adopts a precast concrete panel solution for the main superstructure elements. The ‘Just in Time Delivery’ methodology that can be adopted using DfMA, is ideal given the constrained site location at the heart of the University campus.
Similarly, the redevelopment of the Tetley site on the South Bank is beginning to gather momentum; and the client is committed to delivering a precast concrete panel solution for the first of the office buildings on the site.
There are real signs that off-site manufacture is providing a strong and viable alternative to our traditional construction methods, that resolves many of the challenges that exist in the market. And the projects in the North East, University of Leeds and the Tetley site are real evidence that the DfMA revolution is in full swing.