CREDITS – Client: AgResearch / Contractor: Naylor Love / Architect: Architectus / Structural Engineering: Beca
The new AgResearch development was a mass timber collaboration between Red Stag TimberLab and other parties and consists entirely of mass timber elements which reduce this Workplace wing’s carbon footprint and was an important driver for AgResearch.
The complex includes a Laboratory and Workplace wing. Due to the specialised functional requirements of the Laboratory, this wing was designed with a mass concrete and steel structural system. The Workplace wing is a 2-storey structure with a floor plate of approximately 1,450m2 per level. There are several engineered timber products utilized within the design to optimize the structural solution. Red Stag TimberLab were proud to supply the beam & column structure which contained a total of 333m3 mass timber. The floors and roof consist of Potius panels, the stairs and wall system consist of XLam CLT panels. The total volume of mass timber in the Workplace wing (Glulam, LVL, CLT and Potius) is 665m3 which equates to a total of 440 tonne sequestered CO2.
Because multiple suppliers were involved in delivering the project, careful 3D BIM co-ordination was required between all parties to ensure accurate detailing. Offsite Design were engaged to co-ordinate a full BIM implementation strategy where federated models were issued at each stage of the shop drawing process to ensure clashes were identified and resolved at an early stage. Each timber supplier worked from the same modelling software (Cadwork) which enabled accurate sharing of 3D models for drafting and co-ordination.
Working from our 3D digital model, all Red Stag TimberLab components were CNC fabricated to millimetre accuracy to suit connections and interfaces with other products. The efficiency of digital fabrication becomes apparent in projects such as this where several suppliers are needing to work from the same centralised BIM model.
The Workplace wing relies on Glulam & LVL frames to support gravity loads and post-tensioned CLT walls to provide the lateral load resisting system. Given the high seismic requirements of Christchurch, specialized Tectonus connectors were used at each end of the CLT walls to provide energy dissipation. Mass timber is 20% the weight of concrete and with a very high strength-to-weight ratio, it is the perfect product to reduce seismic demands on connections and foundations. This damage reducing design with state-of-the art technology provides superior performance and occupant safety in seismic events compared with traditional structural systems.
Naylor Love have done a superb job to date in managing the design co-ordination and installation of the mass timber elements. Attention to detail was especially given to moisture management onsite to protect the visually exposed timber elements. The Workplace wing was constructed vertically at each grid enabling the roof panels to be installed as soon as possible to provide weather protection. Polythene sheets were used as temporary weather protection and floor panels were swept clear of ponding water after each weather event. All LVL and Glulam components were factory coated with a weather protective sealer to provide temporary protection against moisture absorption. Attention to detail was also given to protecting elements onsite with temporary plywood boxing, especially to the base of visual columns and walls. The site is incredibly clean due to the high level of factory prefabrication and minimal site works required.
Images Credited to Architectus