Managing the devilish details:
A case study on using BIM
Joy Gumz, CPA, CISA, PMP – Project Auditors, LLC
Pam Welty, LEED AP BD+C – Swinerton Builders, Inc.
Swinerton Builders has been in the construction business since 1888. The employee-owned firm has been a leader in adopting BIM (building information modeling). This session is a case study in how Swinerton has used BIM, the lessons learned, and how visualization can be used to better manage project complexity. Swinerton's motto is, “We build trust in our clients, excellence in our people, and quality in our projects.”
A case study may be understood best as a narrative, based on actual events, which creates an opportunity for conversation, problem analysis, and virtual decision-making. An effective case study transfers specific knowledge by placing the workshop participant in a position to think through choices faced by decision makers in real-life situations. By confronting actual scenarios, participants develop and refine analytical skills for solving similar problems in their own projects (NASA, 2008).
In this paper, we see how BIM is being used during the design and construction of an office building in San Francisco, California. We use the definition as it is defined in the BIM Handbook, “a modeling technology and associated set of processes to produce, communicate, and analyze building models” (Eastman et al, 2008).
The Context – The Construction Industry
The first documented use of the term “building modeling” appeared in the title of a 1986 paper by Robert Aish, then with GMW Computers Ltd., a company that developed a a computer aided design (CAD) system for architects. In the paper, Aish laid out the reasons for what we now know as BIM and its fundamentals: 3D modeling; automatic drawing extraction; intelligent parametric components; relational databases; and temporal phasing of construction processes. (Aish, 1986). The software that Aish was working on at the time, RUCAPS (Really Universal Computer Aided Production System), ran on minicomputers from Prime Computer and DEC (Digital Equipment Corporation). The software and other packages that followed affected how drawings were created, but did not materially change how parties involved in a construction project communicated. The owner, architect/designer, and builder traditionally operated in silos. Communication between the silos was a mix of paper-based documents and conversations via telephone or radio. The 1990s brought e-mail and cell telephones, bringing improvements, but the silos remained. Different project delivery methods, such as design-build and other organizational structures, have been tried to overcome communication problems. However, each method simply has a different set of disadvantages.
BIM is an opportunity to revolutionize the process of development, design, and construction of buildings and facilities. Using BIM, an accurate virtual model of a building is constructed digitally. One of the problems during the design phase is the considerable time and expense required to generate critical assessment information about a proposed design, including cost estimates, energy-use analysis, structural details, etc. (Eastman et al, 2008). As a solution, the process of value engineering (VE) is sometimes applied, but that creates another set of problems because VE changes the design. Using BIM early in the concept and design phases allows more accurate cost estimates to be made early in the project lifecycle.
Another challenge in construction projects is the amount of communication that must take place and the large numbers of parties involved. A study by a Canadian construction firm found certain statistics can be used as a benchmark for large construction projects regardless of the project delivery approach (Source: Maged Abdelsayed of Tardif, Murray & Associates, a construction company located in Quebec, Canada (Hendrickson, 2003)).
- Number of participants (companies): 420 (including all suppliers and sub-sub-contractors)
- Number of participants (individuals): 850
- Number of pages of documents: 56,000
The large number of participants leads to over 360,000 potential communication channels. BIM provides a platform for a large number of participants to collaborate more effectively.
From an owner's perspective, BIM provides multiple benefits. BIM can:
- Reduce changes by enabling visualization and simulation of the owner's requirements,
- Allow energy use to be analyzed early enough to increase building value and meet sustainability goals,
- Enable more reliable cost estimates through automated calculation of quantity take-off from the building model, providing cost estimate data earlier in a project enabling decisions to have greater impact,
- Provide ongoing analysis of the building model against local code and owner requirements,
- Reduce time between procurement decisions and actual construction, allowing for the selection of the latest technologies or trend finishes, and
- Ensure accurate as-built information is available for building fit out and subsequent operations.
Seeing the potential benefits, leading organizations are asking their service providers to use BIM, and in some cases, requiring it. NASA has an internal mandate requirng BIM use on all projects initiated after October 2010 that exceed $10 million. (NASA, 2014). The value of documentation in the facility lifecycle is shown in the Exhibit 1.
The contractor in the case study, the Swinerton Family of Companies, holds California Contracting License No. 92 and is a 100% employee-owned company. They have been building in San Francisco since 1906 and currently delivers projects across the U.S. Their work includes landmark projects such as the Fairmont Hotel and Ghirardelli Square to innovative interiors and specialty projects. As part of its Virtual Design & Construction Initiative (VD&C), Swinerton has become a leader in the application of BIM for 3D object-based modeling, estimating, simulation, and scheduling. The firm has applied BIM on over 162 projects with a combined construction value of over $11 billion. The firm's strategic goal is to take advantage of full VD&C technologies and principles to manage a project from concept through operations. Dan Gonzales, Corporate Manager of VD&C at Swinerton, says, “We've adopted BIM technology and techniques extensively in the planning and design phase. Now, we're working to realize the same value in the estimating, construction management and operational aspects to minimize duplication of effort and increase efficiency and accuracy between the office and the jobsite” (Tekla, 2014).
The project owner, Kilroy Realty Corporation (NYSE: KRC), is a real estate investment trust active in premier office submarkets along the West Coast. The Company owns, develops, acquires, and manages real estate assets primarily in the coastal regions of Los Angeles, Orange County, San Diego County, the San Francisco Bay Area, and greater Seattle. As of December 31, 2012, the Company's stabilized portfolio consisted of 114 office buildings, which encompassed an aggregate of 13.2 million rentable square feet and was 92.8% occupied.
Market and Economic Context
Demand for commercial real estate in San Francisco is heating up. The area in which the building is located, SOMA (South of Market), is viewed as increasingly desirable by technology companies. Formerly a surface parking lot with two 10-to-15-foot-tall, one-story buildings (13,660 square feet,) the land at 333 Brannon was pucrchased by Kilroy in July 2012 at a cost of $18.5 million. The project site zoning is mixed use-office.
The office building is designed to fit in with the historical architecture while providing the latest technological amenities and achieving a sustainability certification, LEED Platinum. The President of Kilroy Realty has stated, “333 Brannan is a great example of our commitment to quality, long lasting product and to the environment. We want this to be an example for what others could and should do.”
- Description: Mixed-use office building with a below-grade parking garage, six floors of office space including ground-floor retail outlets, and a 3,000-square-foot rooftop garden with walking paths.
- Project Delivery Method:
- Estimated Project Cost: $95 Million
- Gross Floor Area: ±180,000 square feet (numbers cited vary from 175,000 to 182,000 square feet)
- Planned Occupancy: Dropbox
- Completion Date: Summer 2015 (Planned)
- Construction Period: October 1013-March, 2015
- Certification: LEED Gold (minimum proposed - Platinum as planned)
- BIM Software Used: 360 Glue
Exhibit 2 is the architect's rendering as submitted to the San Francisco Planning Department.
Project Team Organization
Exhibit 3 shows which parties are using the cloud-based software. The key firms involved are:
- Owner: Kilroy Realty Corporation
- Legal Counsel, Advisors to Kilroy: John Kevlin, Reuben, Junius & Rose
- Design Architect: W illiam M cD onough + Partners
- Architecture & Energy Consultant: Loisos + Ubbelohde
- Landscape Architect: Rana Creek
- MEP Engineer: WSP USA
- Structural Engineer: Nishkian Menninger
- Civil Engineer: Sandis
- Acoustics / AV / Telecommunications: Charles M. Salter Associates
- Contractor: Swinerton Builders
A project timeline with key dates is shown in Exhibit 3. Clash detection is to be complete by August 30, 2014, pending opening design changes. Building commissioning is scheduled to start May 2015 and end in June 2015 when the building will be fully ready for occupancy. Construction phases consist of demolition, basement/subgrade construction, superstructure construction, exterior wall construction and glazing, and building construction interior and finishes. A webcam has been set up to allow the construction progress to be viewed over the Internet. (iBEAM, 2014).
Planning and environmental review and approvals can vary in the amount of time required. A decision by the Planning Department of the City and County of San Francisco determined that, under existing laws, the project application was exempt from further environmental review. The Planning Department found that the project was consistent with the zoning for the area and no substantial changes to the existing neighboring plan since the Environment Impact Report (EIR) had been finalized. This saved the project both time and money. However, the project approval costs were still substantial. Development impact fees assessed were $7,743,124 (SFPD, 2013).
In addition to the project team and facility owners, the neighbors of the 333 Brannan Street area are important stakeholders. Another key stakeholder is the San Francisco government, with multiple staff members and officials involved. This includes Mayor Edwin M. (Mike) Lee, who owner John Kilroy called a “great partner” during the groundbreaking ceremony (Lee, 2013).
Cost and Financing
The project cost is estimated to cost about $90 to $95 million. The building is to be certified as LEED Platinum. In the original planning documents, the cost of the building was stated as about $25 million (SFPD, 2013). Increasing the building's energy efficiency has added about $10 million to costs (Dineen, 2013). This would put the building cost at around $35 million.
In August 2012, Kilroy announced it was issuing 4,500,000 shares of common stock with the stated goals of funding development and redevelopment projects as well as other purposes. The offering would enable the project to be financed by Kilroy rather than through a bank, in some ways simplifying the financing process.
Collaboration and Communication
The design and construction of a facility is a team effort. The closer and more effective their collaboration, the better the project and usually the end result. BIM's strength is enabling better collaboration by allowing data to be exchanged rather than requiring a translation among the paper, data, building materials, and the end-user. Data interoperability is provided by several mechanisms: links between BIM tools, and data format exchange protocols, both proprietary and open standards.
Control and configuration management is such data is complex.
- Different authors work on different parts of the project and their work must eventually be merged.
- Communication among different users of BIM applications must be near real-time.
- The flow of data among participants is not necessarily linear.
- Data to be updated may be stored in different datasets, which requires proper database programming techniques to ensure data integrity is maintained.
One of the challenges in adopting BIM technology is obtaining agreement from all parties of a design project on new methods of working, and for documenting and communicating their work. Some projects using BIM utilize a modified design-build delivery approach. Having a single contract allows the architect, engineers, and contractor to communicate, although silos among disciplines can still deter open communication. Other projects use a performance-based contract approach. This allows for flexibility in how the solution is delivered. On the 333 Brannan project, the owner has contracts with the architect and the contractor. The contractor and architect have a history of working together, including a project for NASA in Silicon Valley where BIM was successfully used. Swinerton has created a standard procedures guide on using the BIM 360 Field software tool. A key aim is to optimize the project team's ability to track field related issues efficiently.
Use of BIM
The project is using BIM to streamline building model coordination and clash avoidance in a real-time format, with access from anywhere. Swinerton, the general contractor, can provide access to any authorized project team member. However, the BIM 360™ Glue software, which provides access to the model, is only being used by Swinerton and its subcontractors. Swinerton's VD&C group helps coordinate subscription access to the software. The BIM visualization software from Autodesk is cloud-based. This allows the construction team to manage the coordination process more efficiently and compress the coordination schedule, providing a single source of truth with real-time information. Because model data is stored in the cloud, there is no need to download, exchange, and manage files. A big plus is that coordination teams know that they are looking at the latest version of a model.
In addition to the BIM 360™ Glue software, software from Assemble Systems is being used for the architectural and structural models, allowing numerous estimating analyses to be performed. Swinerton, the general contractor, is also providing versions of the architectural and structural models using Autodesk's Navisworks® software. The product allows real-time navigation, model review, and model simulation and analysis including 5-D product scheduling. For the schedule, Primavera P6 is being used. The schedule and the model have been kept separate on the 333 Brannan project.
The use of BIM increases quality by preventing many clashes in the first place, and allowing those that do occur to be detected earlier before work is put in place. Coordination can be done more frequently: daily versus weekly. On the 333 Brannan project, the first BIM coordination “kick off’ meeting was held in person. Subsequent weekly coordination meetings are being held via GoToMeeting. There are also periodic in-person meetings with the design team to work out difficult issues. The collaboration has enabled coordination of many items to be determined prior to having the work put in place in the field, and has helped the general contractor maintain the construction schedule. Using the BIM modeling process helps the general contractor reduce schedule issues in the field, which saves money.
The benefits of working in the cloud extend to the jobsite. Project teams can access models in the field to review the model instantly, resolve issues, and allow the jobsite and coordination team to stay connected.
To integrate the benefits of BIM into the contractor's standard workflow, Swinerton has learned the importance of obtaining buy-in from owners and architects. Specific language is incorporated into contracts and project-scoping documents. This language covers the work scope, expected activities, responsibilities, and incentives.
The drivers for Swinerton to adopt BIM were to:
- – Simplify and streamline multidiscipline model coordination and clash avoidance
- – Enable real-time collaboration and tracking of field-related issues while physically in the field
- – Provide a user-friendly field-oriented tool for project personnel to collect, track, and manage trade coordination, QC, safety, punch list, day-to-day field issues, and self-perform work.
BIM can also speed up decisions and improve the quality of those decisions. When people see what is being discussed, their reaction and response time is usually much faster. They are more engaged. Using cloud technology increases accessibility, providing a more viable opportunity to visualize the design process, which improves decision-making quality.
Lessons learned on each project depend on the maturity in mastering the use of BIM. Lessons learned from a similar project by the design construction team were:
- Begin planning with the 3D model at 50% design development; to avoid rework, start detailing only after 95% design development.
- Make sure all trades use a 3D model for design, so that the merged model is as accurate as possible.
- Prepare and make a weekly design, coordination, and construction schedule that links activities together based on install dates for the week ahead.
- Make sure a designated individual from each trade attend every week, and that they are able to make commitments for their respective groups.
- Do not change coordination sequencing during the execution of work, i.e., make commitments and deliver.
This project was construction of the El Camino Medical Office Building (250,000 square feet) and a parking garage located in Mountain View, California, in the San Francisco Bay Area. The cost was about $94.5 million and the work was completed in 2006 (Eastman et al, 2008, p. 373-374).
On the 333 Brannan project, the lessons learned to date have been to:
- Wait for full design to be complete prior to starting BIM coordination.
In addition to the lessons learned above, the top three things that the project engineer in charge of BIM coordination on the 333 Brannan project will take to their next project are to:
- Determine the priority of trades,
- Have the structural engineer review the model on a regular basis to buyoff on major slab or structural wall MEP penetrations, and
- Use the modeling program add-ins to work in conjunction with BIM 360™ Glue.
Power of Virtualization and Application to Other Industries
Modeling and virtualization has been used in other industries to reduce project cost. Using virtualization and simulations reduces the number of change orders that, when requested too late, can increase project cost (Gumz, 2008). Boeing used modeling in the design of the 777 airplane. They pre-assembled the airplane virtually, which eliminated more than 6,000 change requests and achieved a 90% reduction in spatial re-work. It is estimated that Boeing invested more than $1 billion dollars to purchase and set up their parametric modeling system for the 777 family of planes. Computing power has dropped dramatically. In contrast, Sikorsky spent only $2 million to set up a virtual reality lab for the CH-53K helicopter, a $4 billion program, with the first customer being the US Marine Corps (Dempsey, 2014). John Deere, the tractor manufacturer, has defined how it wanted its tractors to be built by defining design-for-manufacturing (DfM) rules and using modeling software.
BIM is much more than a software tool. To capture the benefits of BIM requires significant changes in the project delivery process, selection of contractors, relationship of project participants, and the contractual agreements between them. Traditional contract terms are tailored to paper-based practices. A commonly used project delivery method, design-bid-build, inherently limits the use of BIM, so organizations wishing to leverage BIM to its fullest have to consider design-build or other project delivery methods. BIM facilitates collaboration among project participants, proactive ly reducing changes and errors, and ultimately enabling projects to be delivered in less time at lower cost. General contractors in the United States are recognizing the benefits of BIM, adopting it, and requiring their subcontractors to use BIM. And BIM can be used even when the architecture and engineering firms have not adopted it earlier in the project life-cycle. Organizations are learning that BIM's power of visualization, coordination, simulation, and optimization allows them to better meet customer, design, construction, and program requirements. Does your organization use BIM?
This paper has presented a case study about a building project using BIM during the construction phase. We hope that you have learned about how BIM will be revolutionizing the contruction industry in the future.
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© 2014, Joy Gumz and Pam Welty
Originally published as a part of the 2014 PMI Global Congress Proceedings – Phoenix, Arizona, USA