BIM and digital design: a closer look at how mass timber moves from the factory to the jobsite
Le Corbusier’s fascination with the automobile is evident in the various photographic recordings of the architect of him posing proudly next to a car in front of his work as an architect. According to the Franco-Swiss architect, in addition to enabling more efficient and economical construction, the industrialization of architecture could form the basis for improved aesthetic results in the same way that the modern car chassis supports creative and modern design. of the automobile body. Yet while vehicles have undergone impressive changes since the 1930s, it can be said that architecture has been slower to adopt advances from other industries.
But that gradually changed. Driven by concerns about sustainability, the use of non-renewable fossil resources and efficiency, coupled with a growing demand for the construction of new buildings and more accessible infrastructure, the construction industry has incorporated many new technologies. , including those adopted by other industries. In addition, renewable materials such as wood have been identified as an ideal building material, especially when incorporating innovative mass timber products such as CLT and glued laminated timber, methods and processes design such as BIM and DfMA, visualization tools such as VDC, and manufacturing tools. such as CNC. We know these are a lot of acronyms, but we’ll try to clarify them throughout this article.
Design for Manufacture and Assembly (DfMA) is a design approach that focuses on both the ease of manufacturing parts of the product and the simplified assembly of the final product. It combines two methodologies; Design for manufacture and design for assembly. That is, from the early stages of creation, decisions are based on avoiding problems during construction and improving efficiency.
This is an approach used in many industries and in construction it is particularly well suited to solid timber using products such as cross-laminated timber (CLT) or glued laminated timber (glued laminated timber). ). This is because when designing and building with solid wood, the construction itself is much more of an assembly of parts and is quite different from the design and construction of a more traditional construction. Solid wood panels, beams and columns are fabricated off-site and transported to the job site, prefabricated with all stops and holes to accommodate pre-defined installations including MEP (mechanical, electrical and plumbing). In order for the process to run smoothly from start to finish, it is essential to get organized from the early stages of the project, allowing various teams to connect from the start to contribute to the final product, avoiding delays and setbacks on the site.
It is at this point that Building Information Modeling (BIM) helps a lot in the process. BIM refers to a set of technologies, processes and policies that enable various stakeholders to collaboratively design, build and operate a facility in the virtual space, forming a reliable basis for decisions throughout of the building’s life cycle, from the first ideas to demolition. . In other words, for any project to run efficiently, it is important that everyone speaks the same language, BIM. It enables visualization and simulation of all parts of a job, providing an understanding of the assembly and feasibility of the modeled solutions. It also supports a shared understanding of the design solution through the 3D model, which can facilitate cooperation between the project team and eliminate the risk of common mistakes in the interpretation of 2D drawings. Combined with this, the model can be exported to several other structural and thermal analysis programs, and can also generate files for machining by computer numerical control (CNC) machines.
Ideally, a well-defined project flowchart, with all those responsible for each area receiving and returning with their contributions, helps ensure that the project runs seamlessly, leading to smoother manufacturing and construction. In a nutshell, this means that once the architect has completed the initial design, structural and installation engineers should already be involved to pre-launch their parts. The project then returns to the architect for the development of further details. At each of the design stages, the entire design team is involved, including those responsible for manufacturing the parts or those in charge of assembly; these disciplines must be well defined and detailed. It is observed that the use of BIM during the design phase reduces the time required to convert architectural drawings into manufacturing drawings and improves coordination between the design team and external manufacturing facilities, which is vital for the success of the construction.
The 18-story Brock Commons Tallwood House at the University of British Columbia (UBC) is a success story. In this project, Virtual Design and Construction (VDC) has been extensively used to support the design and construction analysis among the different teams of this complex project. BIM also describes the properties of each of the different building elements (connected to an extensive database), with the creation of a virtual project prototype whose performance can be simulated and tested. VDC is a subset of BIM mainly focused on the geometric 3D representation of an installation. The VDC model facilitated planning and communication in various aspects of the design, pre-construction and construction phases, as it provided a complete, accurate and highly detailed representation of the construction.
In the case of this project, as described here, a VDC model was developed from the start of the project, covering all construction elements from the structure to interior finishes to mechanical and electrical systems. The process was complete and all details and services were included in the template. This model aided decision making during project development and allowed modelers to work closely with the design team, quickly incorporating design iterations and updates, keeping the team informed. any problem or conflict to be resolved and ensuring that the model was always precise and detailed in its representation of the project.
During pre-construction, the VDC model was important for the creation of a two-story prototype of the building, to test the solutions developed for the project and the viability of the construction. The VDC model also served as the basis for the manufacturing model which was used directly by CNC machines and for stress testing of CLT panels.
A carefully planned and integrated project, with good organization, will lead to a much faster construction. In the case of this 18-storey building, the wooden structure was completed less than 70 days after the arrival of the first prefabricated elements on the site, which represents a significant saving of time and, consequently, of money for construction. More time in design, less time in construction. This is a promising scenario, especially considering the use of renewable materials, in this case wood.
Learn more about the potential impacts of BIM and solid wood construction in this report from the BIM TOPiCs research lab at the University of British Columbia.