BIM watch

Bringing building information modeling into the glazing industry
By Will Ikerd
August 4, 2009

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Building Information Modeling will fundamentally change the glass and curtain wall industry before 2015. This bold claim is based on the observation that BIM is a process that acts as an enabling catalyst to three major building industry drivers that especially dominate the fenestration industry: sustainable design, lean construction and integrated project delivery.

For contract glaziers, glazing system suppliers and consultants, the opportunity and challenge with BIM is to understand what the new BIM process is, its tools and how this new process will change their businesses. They then must choose the best path to transform their firms, staff and corporate thinking into a BIM delivery process. Many companies will find that the greatest hurdles to a BIM transition are the psychology of changing a corporate culture and process, not the technology of installing a new software tool.

A process, not a tool

"BIM" has too often been erroneously interchanged with “3D CAD” in design and construction literature today. Some view it as being just the next digital tool to come along, just as CAD replaced board drafting. Others make the analogy of "BIM is to CAD as a pen is to a pencil." This thinking allows BIM tools to be viewed as something that can be simply appended into a company’s traditional workflow and staff. The foundational flaw in this thought is that it is myopic to the BIM process change. The BIM process—defining building information in databases that can be electronically shared automatically among integrated companies—will change the industry. While BIM software offers visually rich 3D models, the focus should be on the processes.

Companies that attempt implementing BIM software applications with their traditional curtain wall processes and staff will find little success. This is like investing in a jet plane and having a non-flight trained staff drive it down the street like a bus; it’ll never get off the ground.

Information sharing

Figure 1

Figure 2

A proper perspective of BIM recognizes the concept of a relational database of the building’s information. The goal is for each stakeholder in the building process to have their own BIM that can communicate digitally with other stakeholders’ BIMs. In an expanded view of the building envelope, these stakeholders include the building owner, facility management team, glazing contractor, glazing system supplier, general contractor, architect, structural engineer, mechanical engineer, curtain wall consultant, façade engineer, acoustical consultant, government permitting agencies and BIM consultants (see Figure 1). There are many challenges to smooth data transfer among the different stakeholders on a building project. This is why the new emerging role of the BIM consultant in companies as part of the construction team will be an increasing trend in the building envelope industry in the years to come.

As a relational database of building objects with a graphically rich interface, BIM can organize and link vast amounts of façade information from design to construction. The BIM process can manage many types of building envelope information beyond 3D models, including: wind loads, wind tunnel tests, structural live load movement requirements, material finishes, glass type, interlayer type, allowable deflection on framing systems, light transmission, thermal information, curtain wall profiles, test criteria, drift and earthquake requirements, sound transmission, fabrication part numbers, installation schedules, and field inspection data.

An example of this data-rich use of BIM can be seen in the unitized glass curtain wall model of a 20-story building shown in Figure 2. This façade BIM was developed by BIM consultants who specialize in building envelopes at Dallas-based Raymond L. Goodson Jr. Inc.’s Department of IPD for the projects curtain wall consultant Vertical Solutions, Dallas. This example illustrates the development and implementation of BIM to store and analyze field record glass and curtain wall data in an intuitive model that owners can easily understand, that facilitates cost analysis of the glass and that hyperlinks to field report documents. This allows BIM models to become a 3D Web page of a building that links to documents, plans, sketches and photographs.

Glass industry adoption

The first major driver of BIM process adoption in the building envelope industry is sustainable design. The BIM process will develop alongside these sustainable issues in curtain wall, and the two trends will progress together, because BIM is an enabler to sustainable design. BIM-enabled thermal and structural analyses also will aid the development of more sophisticated curtain wall systems to address greater energy efficiency.

Lean construction is another major driver of BIM in the glass industry. Unitized curtain wall already builds on many of the lean construction methods to reduce waste in time, material and field labor, and increase trade coordination with on-site materials. These benefits are expanded with BIM by allowing teams to proactively solve fabrication and fit-up issues virtually in the models before they are built.

The BIM process enhances just in time delivery of unitized systems from the factory by linking scheduling information to the 3D models. This is called 4D modeling: 3D modeling plus the dimension of time. BIM-enabled production and project planning with JIT can also increase inventory turns and reduce the amount of working capital required for fabrication. Additionally, BIM-enabled planning of erection and installation sequence can facilitate fewer workers at one time on site, resulting in more efficient, faster and safer installations.

For more information, the Associated General Contractors of America, Arlington, Va., is authoring the Contractors Guide to Field BIM that includes a chapter on curtain wall that focuses on GCs using BIM on site to addresses many lean construction goals.

Finally, integrated project delivery and the related code and industry changes that go with it will significantly drive BIM forward in all construction industries, including glass. The BIM process is enabling variations of the IPD contracting form that fosters combined risk and reward across traditionally opposing project/stakeholder relationships. Like sustainable design, the concept of BIM-enabled IPD is a trend that will rapidly grow in a symbiotic way in the years to come. The exciting aspect of this industry change for glazing system suppliers and contract glaziers is that those who are BIM-enabled have the opportunity to emerge as a highly valued specialty contractor that is retained early in the design process in this new collaborative IPD contracting form. These companies will achieve this by hiring BIM consultants internally or by collaborating with BIM consultants in a sub-consulting role.

The construction industry’s change to BIM is happening faster than many realize, and rapidly expanding in design and construction. Curtain wall companies will have to provide committed competent BIM services to compete and survive on projects of any significance within the next five years. BIM requirements will be ubiquitous on requests for proposals for new work in the near future. This will happen as a result of the three BIM drivers previously discussed: sustainable design, lean construction, and IPD. The curtain wall industry of 2015 with BIM will look dreamily different than it does today. It is an exciting time for companies to leverage the opportunities while they overcome the challenges of the new BIM process that uses dynamic new BIM tools.

Read more Glass Magazine articles on BIM:
BIM users report 300 percent-500 percent ROI
Electronic construction

The author is director of integrated project delivery for Raymond L. Goodson Jr. Inc., Dallas,