21st June 2018

Driving innovation and efficiency through off-site construction – Precast concrete

Striving to deliver value and quality is at the heart of how we approach our civil and structural engineering design.  It’s for this reason that we have been championing off-site construction and pursuing innovation in panelised and modular technology. We’ve successfully delivered projects across sectors including education, housing and the public sector using panelised solutions, and currently have projects utilising either precast concrete or cross-laminated timber panels. So why is it important and what difference can it make to construction projects?

Quite simply, these construction techniques are proving quicker and less disruptive environmentally to construct, and of good quality when compared to traditional building methods.  On large residential apartment schemes, the on-site skilled labour shortage that is often encountered in traditional build (eg. Bricklayers) can be mitigated by off-site production of the frame and cladding elements.

A great example of using a precast concrete structure is at Eltham College in South London. Over the past year, our London Studio has been working alongside Levitt Bernstein architects on the delivery of a precast concrete structure for the innovative new £10m Tuberville Building at the college. We are the Civil and Structural Engineers for this project which started on site in July 2017 and is due for completion in early 2019.

The ground to second floor structure was formed predominantly from precast concrete, much of which is exposed, acting as a visual feature and contributing to the energy efficiency of the building through exposed thermal mass. To achieve a high-quality finish for the internal exposed concrete we have maintained close collaboration with the precast suppliers from their appointment through to installation.

Part of this coordination and collaborative process has involved visiting the panel manufacturer’s factory to review the manufacturing process, the capabilities of the product and to fully understand the level of quality that is achievable. The manufacturing plant is on the same site as the quarry which provides all the raw materials for the cement used in their pre-cast concrete products.

Using a panelised concrete system has made the construction period shorter, quieter and safer, a clear winner as Eltham College site is located in the heart of a residential area. The structural frame, formed from a mixture of precast hollowcore and lattice girder slabs spanning onto twin-wall panels and steel framing elements, was erected significantly quicker than an equivalent in-situ reinforced concrete frame.  The precast concrete frame is now complete, and erection of the steel roof frame is underway.

This is just one example of where we have harnessed the benefits of precast concrete construction.  With the same architect we completed a new junior school for Withington Girls’ School in Manchester as few years ago, again using a panelised precast concrete system.

Our wealth of knowledge and our cross-studio experience of providing engineering design services for developers, contractors and precast concrete manufacturers, perfectly places us to consider the construction options at an early stage to advise on the most suitable solution and procurement route early in the design process. By doing this we can effectively work towards optimising speed of build, structural performance and delivery of the most economical, quality structures for our clients.

Driving innovation and efficiency through off-site construction – Precast concrete