Under the wood at Brock Commons Phase 1
In the next two weeks at Brock Commons Phase 1 all the mass timber elements will be fully encapsulated and the full structure will be complete. There has been a lot of discussion around the speed of construction on this project by leveraging prefabricated elements, with the team erecting 17 levels of mass timber structure in only nine calendar weeks (much less than that in total working days). It has been remarkable and every owner looking to develop a similar project is intrigued, as the impact to project carrying costs (interest on construction financing, general conditions reductions, etc.) and opportunity cost of capital (closing projects faster, recouping upfront investment and deploying that capital to the next incremental project) could fundamentally shift the way project proformas get built and investment decisions are made.
From a process and technology perspective, the project benefitted by an integrated design process and having one central, fully integrated 3D/4D model (CATIA 3DEXPERIENCE for geometry authoring and scripting, DELMIA 3DEXPERIENCE for simulation) that went direct to fabrication for multiple building systems, including the mass timber and connectors. One aspect of prefabrication at the project that has not been talked about is the selective use of prefabrication for the MEP systems. This is a large value driver to the project as it is imperative that the rest of the subcontractors can keep pace with the speed of the structural construction. After collaborating closely with Urban One Builders (the Construction Manager) and Trotter & Morton Mechanical (Mechanical subcontractor) as a team we determined that we could optimize the bathroom plumbing stacks down to 2 repeating layouts for the full building and since the central CATIA model contained all the pre-CNC’d penetrations in the CLT slabs for MEP, we used the native CATIA piping detailing applications to generate the prefab outputs required to precut all pipes, order and place fittings, hangers, then assemble rapidly on site.
A second area that was identified is the mechanical room. A mechanical room in a project like this can take approximately 800 man hours to build. Mechanical rooms are a good target for prefabrication because there is a lot of complexity, code requirements, long term maintenance requirements, etc. in a relatively small physical space. Therefore, much of the risk is removed and the installation process is optimized via prefabrication by system.
Net-net, similar to the mass timber structure and prefab façade panel installation, the mechanical installation productivity on site to date has been extremely efficient with results dramatically improved over a recent traditional stick built concrete 18 story student residence project recently completed on the other side of the UBC campus. Mass timber construction is all about speed and extending the prefab beyond the wood elements and facade has been a great way to further reduce schedule on the project so far.