About the Project
WYNG Gardens is located within the historic conservation area of Cambridge. Just off of the main high street, overlooking the River Cam, the four-storey building offers University of Cambridge students a total of 72 new ensuite bedrooms with kitchen facilities and a common room area on every floor.
Partly funded by the WYNG Foundation, the development sits on roughly the same footprint as the former St Clement’s Gardens houses. The old terraced houses were in a poor state of repair, with subsidence issues and cracks both internally and externally and sub-standard amenities. This, combined with poorly conditioned services in constant need of repair - made restoration impossible.
The building’s interior has been designed to offer a high standard of accommodation for the students of Trinity Hall, providing a further 16 units of undergraduate accommodation than the previous facility. Each room includes a work station with free high-speed internet connection.
The Challenges
Due to the location of the site, a lightweight structural frame was vital. Furthermore, to fall in line with term times, a rapid build prefabricated system was essential. Due to these key drivers, together with the need to limit disruption, cross-laminated timber was the only viable structural solution.
The main challenges were a restricted site with no perimeter access together with engineering the Mansard Roof. The roof structure tapers at 50 degrees, with four sloping sides, which are horizontally split by differing gradients, the lower being much steeper. Propping of the roof structure in its temporary state, ensured the safe installation of the Mansard Roof.
To overcome the issues surrounding the restricted site, early planning with main contractor, Balfour Beatty was essential. This ensured all site requirements were met for the delivery and installation of the structure. The use of cross-laminated timber as the core structural component, resulted in fewer delays from bad weather and an increased level of accuracy. The lightweight, yet robust structure meant that there was an increased speed of construction, allowing early access for follow on trades which again reduced the overall programme time.
The Solution
B&K Structures, supported the design team throughout the design stages, including all of the connection detailing. Rectangular in shape, the structure encompasses CLT loadbearing walls both internally and externally. Steel lintels were used above the central corridor to support double spanning CLT floor panels above, whilst steel down stand beams are used to transfer heavy loads at the back of the structure to the entrance gate area.
Cross-laminated timber forms the staircase from the ground to the upper floors which incorporate a distinctive arrangement with quarter landings that cantilever from the stair shaft walls. Likewise, the lift shaft structure is constructed with cross-laminated timber.
CLT was designed intelligently to act as deep beams to allow significant loads at the back of the structure to be transferred around the ground floor’s curved glazed entrance area, with steel ‘goalposts’ used to support the masonry and cross-laminated timber beams above. The curve was continued for the full height of the structure with the use of CLT facetted sections and topped with an isometric dome. The roof around the dome was also formed with CLT panels which incorporated large circular notches.
A pitched, slate-coloured Mansard Rooftops the remainder of the building, reflecting a number of similar styled roofs in the area. The lower slope of the Mansard Roof involved cross-laminated timber wall panels erected on a slope as well as dormer windows, which also utilised CLT, projecting vertically from the sloping roof.