Abingdon School in Oxfordshire is one of the oldest independent day and boarding schools in the country, dating back to the 13th Century. The new Beech Court Pavilion connects the existing Amey Theatre to the main school via a dynamic, multi-functional space that aims to enhance the student experience with a hub for dining, study, and social activities. The design seamlessly blends a complex steel canopy frame, with an exposed glulam diagrid roof and expansive glazed elements, to create a visually impressive communal space for students and staff.
Beech Court Pavilion was achieved through close collaboration between all project partners including David Morley Architects, structural engineering consultants’ engineers and Beard Construction as the main contractor. B&K Structures (BKS), the UK’s leading provider of engineered timber and hybrid structures, were involved from the initial stages and awarded the contract to design, fabricate, and erect the complex octagon roof. The roof features four quadrants, innovatively conjoined at stepped interfaces, with precision engineered glulam beams manufactured by BKS’ timber supply chain partner Rubner.
Creating a connection to nature and biophilic design were important client requirements. As such, the natural qualities of exposed structural timber were the ideal solution, and the materials also visually integrate with the green roof planting and extensive glazed elevations.
Alastair Wood, Project Architect for David Morley Architects, explains: “The design concept was to create an elegant pavilion that provides a flexible dining space within a garden setting. This put emphasis on the transparency of the Beech Court Pavilion, Abingdon School a new dining pavilion featuring a complex steel canopy frame and feature glulam diagrid roof façade, daylight and connection between inside and outside - a key element of which was to have a continuous glazed external perimeter, with a roof floating above and generous overhangs to provide solar shade to the interior and shelter to the outdoor spaces”.
Design
The roof structure of Beech Court Pavilion was technically and structurally complex, with the visually striking but unusual shape meaning an intricate design was required.Alastair Wood states: “Significant complexity was introduced as the 3D ‘pringle’ (hyperbolic paraboloid) was also faceted plan with an octagonal perimeter tapering to a square central rooflight. This created variation between facet sizes and significantly more precise structural considerations, with more intricate connections required to maintain the elegant appearance.”
The concept also called for a structurally minimalist design. He adds: “The decision process for the structure was to do more with less – structurally and environmentally – using geometrical efficiencies to provide an uninterrupted span with the least material.”
The intricate roof structure of Beech Court Pavilion requires meticulous coordination between B&K Structures, follow-on trades, and subcontractors due to its complexity, aesthetic demands, and the constraints of an active school site. Using Trimble Connect, the project team visualized and fabricated complex ‘3-legged’ columns, ensuring successful assembly that would have been difficult with 2D drawings.
A temporary central support tower was used to facilitate construction, allowing the roof to become self-supporting upon completion. The project required precise frame analysis and a phased installation method to manage structural deflections and challenges efficiently. The final exposed diagrid glulam roof is testament to timber construction’s aesthetic and structural advantages. Seamless collaboration between architects, engineers, and subcontractors, enabled by IFCBIM model exchanges, using Tekla Structures software, significantly accelerated the drawing production, issue resolution, and approval process, ensuring an impressive final result completed within a tight schedule.
Construction
The complexity of the design posed unique challenges in terms of planning, prefabrication, and subsequent installation - requiring substantial timber expertise and experience. Therefore, BKS’ expert team were involved from Beech Court Pavilion, Abingdon School the initial stages, to ensure that assembly could be conducted to a very tight timetable and an unusually high degree of accuracy. The diagrid roof was constructed from 35m3 visual grade glulam beams. The fine tolerances meant that BKS needed a trusted supply chain partner, bringing on timber specialist Rubner who they had previously collaborated with on a range of other projects. Thorough planning and prefabrication of temporary falsework was required to facilitate the precise erection of the major trusses and diagrid roof.
BKS Operations Manager, Andy Holland, explained: “The method statement we determined with Beard Construction required us to build the roof as four separate quadrants supported by temporary falsework columns. However, as they met at different angles of pitch, the geometry of the connections was overly complex and required strong technical skill. Asa result, a constantly changing variety of stub plates coming off the main steelwork were required. It would have been near to impossible to have constructed this in precast concrete.
The buildability and temporary works review was unusually challenging, and the tolerances on both fabrication and installation were far tighter than normal: a maximum of 5mm rather than 10mm, meaning even a very small error on the steelwork would have made it impossible to align and fix the glulam beams”.
Regular inspections by BKS engineers ensured the complex roof form was not subject to any creep on tolerances, and the aesthetic integrity of the final design was preserved with minimal but skilful alterations on site by these erection team, including cutting, realigning, tack-welding, re-checking and fully arc welding in place.
The Beech Court Pavilion project also presented logistical challenges. Construction was originally scheduled for the summer, to take advantage of the school’s closure in July and August. However, it became necessary for work to commence in December meaning a key challenge was avoiding disruption to school life while also managing exposure of the materials to wet weather. B&K Structures committed to minimising interruptions to lessons and sports by thoroughly pre-planning the installation.
BKS Operations Manager, Andy Holland, said: “By meticulously scheduling each lorry load, and thereby ensuring the number of elements we had to lay down on the floor was minimal, we reduced the number of deliveries and overall disruption when work continued into the spring term.”
This thorough preplanning, based on expertise gained over 20 years of timber experience, ensured the onsite phase of the roof installation was completed flawlessly by BKS – and the site team completed works ahead of schedule, in only eight weeks. Utilising an offsite construction approach Beech Court Pavilion, Abingdon School also meant the size of the onsite workforce and amount of equipment required could be reduced, with the installation of the roof on Beech Court Pavilion requiring a forklift, telehandler and an Igo self-drive mobile tower crane.
Sustainability
Beech Court Pavilion exemplifies the environmental advantages of structural timber. The use of timber not only met the clients’ aesthetic and biophilic requirements but also improved the sustainability credentials of the project.
In line with circular economy principles - when correctly fabricated, installed and maintained - structural timber offers a long working life with the potential for reuse. Also, compared to alternative construction materials, solid timber products such as cross laminated timber (CLT) and glulam are far less energy-intensive to produce and use.
Finally, as trees grow, they absorb and sequester carbon, meaning the use of responsibly managed timber in place of more carbon-intensive materials such as concrete, can reduce the total carbon impact of the project.
The 34.896m3 of glulam used on Beech Court Pavilion sequesters 24.543 tonnes of CO2e from the atmosphere. As the timber used has full PEFC chain of custody certification, due to the responsible management of the supply chain forests, the client can be assured that all the timber used on the project will have been regrown in just7 seconds.
Finally, structural timber as an offsite solution has numerous sustainability benefits, including radically reduced material wastage (less than 2%), and a reduction in the number of vehicles delivering materials to site, resulting in lower emissions.
The visual impact of the Beech Court pavilion with its exposed diagrid glulam roof is hugely impressive and highlights the aesthetic and biophilic benefits timber can bring to an education setting. The final flawless result Abingdon is testament to close design collaboration and technical expertise by B&K Structures and the full project team.
Awards
- Winner – Installer of the Year (B&K Structures) - Structural Timber Awards 2024
- Finalist – Education Building Award - Schüco Excellence Awards 2024