30th October 2020

Carry on CABI

Perega and Perega Clear Structures are pleased to announce we have recently completed work on one of the UK’s anticipated building projects, The Centre for Agriculture and Bioscience International (CABI) new headquarters in Wallingford, Oxfordshire.

With construction complete and CABI’s 140-strong staff set to move into the new site in the coming months, it’s been an exciting and rewarding project for Perega to be involved in, putting our skills to the test to address some unique challenges.

Involved from the very outset of the build, working with forward-thinking architectural practice, Scott Brownrigg and contractor Barnwood Construction, our expert teams provided full civil, structural and glass engineering services and consultancy for the ambitious project.

The Perega team, which included senior engineer Corina Robea, provided consultancy on the first floor structure of the aesthetically striking new building. This level consisted of a hybrid precast/in situ podium, where we suggested exploiting a precast twin wall system for the concrete walls, encouraging the use of precast concrete to provide a high-quality finish to exposed surfaces and deliver the thermal mass required for the scheme.

Further, we advised on an extensive green roof, helping to design a robust steel roof structure to support the weight of the soil and turf. This, in turn, was positioned on steel columns directly bearing onto the podium columns below.

Our civils team was also kept busy, sharing its considerable knowledge and skill for the design of the site’s drainage and hard paving. This required the detailed development of a strategy, which was challenging due to the high water table and infiltration rates.

Perega Clear Structures proved pivotal in the delivery of CABI’s glasswork, providing consultancy for the building’s glass balustrading across the internal landings and bridges, as well as the full height frameless office partition screens.

One challenge they faced was in the choice of glazing system originally specified for the project. Here the manufacturer’s testing did not match with Perega Clear Structures’ structural calculations, raising questions around the system’s suitability. However, following considerable and extensive investigation, a hybrid design was developed, allowing the original specification to be delivered with minimal adaptation or disruption.

To help fund the development of the new office, CABI had also sold several old playing fields to leading housebuilder CALA Homes for the development of 91 new residences, a play area and a wildflower meadow. During the planning phase, some concern was voiced about the site’s proximity to an Area of Outstanding Beauty. As such, all parties involved in the project had to ensure that this unique natural habitat was protected throughout the construction journey.

The new offices are sustainable to the core, reflecting CABI’s ongoing work to encourage biodiversity and eco-friendly philosophy. Designed to be as energy-efficient as possible, materials, components, and systems were specifically chosen on their high-performance, low impact credentials. For example, a state-of-the-art passive ventilation system was devised, and a ‘Fabric First’ approach taken to ensure low U-values, reducing the need for carbon-intensive mechanical HVAC.

Commenting on our work at CABI’s new offices, Corina says, “It’s great to be involved in a project for such a prestigious organisation doing such important work. Building to a sustainable brief always makes for interesting work and there were many specific, material choices which needed to be made to deliver structural integrity but also ensure carbon neutrality. Furthermore, we needed to be sensitive around the visual impact of the finished structure which led us to make some swaps, for example, switching from poured to precast concrete to deliver a more pleasing effect.

She continues, “I’m particularly proud of the design of a set of impressive, central scissor staircases. We played an integral role in ensuring the feasibility and stability of this striking feature and I’m so pleased with the results, they really add to the overall aesthetic whilst serving a useful function.”

Rob Parsell, Associate at Perega Clear Structures concludes, “One of the most satisfying parts of the job is being able to provide a constructive answer to what initially looks like an insurmountable problem. Working in a collaborative fashion, with the glazing system manufacturer, and maintaining an open dialogue allowed us to pool our collective expertise. Ultimately, we were able to develop a workable solution without compromising on the original vision and design of the finished building, a win-win situation all-round.”

To find out more about Perega’s work within the commercial property sector, click here.

Image credit: Hundven-Clements Photography