BIM success on the Renaissance Boston Waterfront Hotel

Design & Construction Team

Owner: Marriott International, Washington, D.C.
Building information modeling manager: GHAFARI Associates, LLC, Dearborn, Mich.
General contractor: Payton Construction Corporation, Boston
Design architect: The Stubbins Associates, Cambridge, Mass.
Structural engineer: LeMessurier Consultants, Inc., Cambridge, Mass.

In the past, the design and construction supply chain relied on 2-D, paper-based documentation to share design, detailing, construction, and fabrication information. Working within this paper-based delivery system, each project participant constantly interprets, creates, and then converts project data into a set of 2-D, paper-based documents that are passed to the next participant to be re-interpreted, recreated, and delivered as a new set of 2- D documents. The conventional 2-D-based delivery system may work well in a well-defined design/construction schedule where design changes are minimal and operations are sequential.

However, in most real-world situations, design, detailing, fabrication, and installation are increasingly concurrent activities.

Uncertainty, late changes, and the inability to adequately manage the impact of those changes are some of the main reasons for schedule delays and cost overruns on projects.

This fragmented and piecemeal method of representation is error prone and provides little opportunity for the design and construction team to eliminate waste and maximize the value of automated design and fabrication. The fundamental limitation of the paperbased approach, even though it may be produced by the latest CAD technologies, is that it requires someone to assemble and interpret its embedded information.There is very little that technology can offer to streamline the crossdiscipline decision-making processes.

The constant process of interpreting and re-assembling project information is time consuming, and as a result, design teams are forced to manage multiple, redundant, incomplete, and fragmented representations.

The result—especially when project schedules are fast-tracked—is that too many key decisions that may affect coordination of the overall project are postponed until more information is available. At the same time, sub-components are manufactured to meet the schedule with less certain information increasing the risk for unforeseen changes and associated costs during construction.

The increasing use of building information modeling (BIM) for detailed design and fabrication is creating the potential for realizing breakthrough opportunities for owners, designers, contractors, detailers, and fabricators not possible when using the conventional 2- D-based delivery methods. Design and construction teams can be enabled to work more collaboratively and to better apply lean methodologies to eliminate waste and gain overall efficiencies through direct data sharing, increased automation, digital fabrication, and offsite assembly. The direct exchange of 3-D data among design and construction teams at the right time and with the appropriate level of detail is essential to maximizing the benefits for the overall project. In particular, it leads to producing fully coordinated solutions before construction, which makes it possible for sub-contractors to increase their reliance on offsite digital fabrication.

Large facility owners such as General Motors, which during the past several years has piloted those enabling technologies and demanded their use across its design and construction supply chains, are starting to report breakthrough results in schedule, cost, quality, and safety on their projects (More information can be found in the article, "Virtual Reality Isn’t Just For Gamers Anymore: GM Utilizes 3-D Math-Based Technology to Design and Construct New Facilities," www .gm.com/company/news_events /press_releases).

This article reports on progress being made by extending the same highly successful 3-D-enabled methodologies used on recently completed design/build automotive projects to an entirely different building type and delivery system; namely, a design/bid/build delivery approach for the Renaissance Boston Waterfront hotel (RBW).

The project

The RBW is a new 22-story hotel owned by Marriott International. The hotel, currently under construction, will be completed in the fall 2007. It will feature 471 guest rooms, including 21 suites. The hotel also will contain more than 20,700 square feet of meeting space, including a 10,700-square-foot ballroom, a junior ballroom, a restaurant and restaurant lounge, room service, and banquet facilities. The hotel will also provide a fitness center with a lap-pool and treatment rooms, an outdoor terrace, and a business center.

Realizing the limitations inherent in the 2-D delivery system, and the potential of using 3-D BIM to avoid costly change orders and associated schedule delays, Marriott International introduced 3-D BIM as a value-added tool for the already assembled design and construction team via GHAFARI Associates, an integrated architectural and engineering company and leader in 3-D-enabled project delivery. On the RBW project, GHAFARI acted as the 3-D BIM integrator.

With the exception of architectural documents, which were produced in part using BIM software by the design architect, the majority of the project’s 800- plus, 2-D construction documents were produced using 2-D conventional CAD drafting. Due to reduced floor-to-floor heights during the design of the hotel, Marriott International became increasingly concerned about the coordination of the mechanical, electrical, and plumbing (MEP) systems in the available ceiling spaces on each floor and potential impact on schedule.

To have timely impact on the project, one of the challenges that faced GHAFARI’s BIM team was to model the 22-story building entirely and accurately. This was required as quickly as possible to identify potential coordination problems that may affect early bid packages, such as structural steel. At the same time, GHAFARI’s BIM team needed to adjust its delivery workflow, which was developed for the integrated automotive fast-tracked design/build delivery system where GHAFARI was the architect and engineer, to a design/bid/build delivery system working with external design and construction teams.

The process In a design/build situation, the design team can work very closely with the sub-contractors so that 3-D information can flow from design to detailing and fabrication with little rework.

However, in the design/bid/build delivery situation, the 3-D BIM effort needs to be carefully balanced so that it focuses on identifying critical design issues without over-coordinating the facility subsystems to a level that may limit choices for selected subcontractors.

Therefore, GHAFARI divided its 3-D BIM effort into two phases.

In the first phase, the facility’s 22 stories were fully modeled from existing bid-level documents. Automatic interference detection was used to detect design collisions, which were reviewed and grouped into two categories: those requiring design modifications; and those that could eventually be resolved during MEP coordination with the subcontractors. Thousands of design interferences were originally identified by the software. Those were then carefully examined and reviewed with the owner and the design teams and narrowed down to a manageable list of relevant area that would require re-issue of the design document. The design teams then reviewed the issued design documents based on those interference reports. As a result, revisions to the structural steel and to ceiling heights were issued before steel was fabricated. In addition, a redesign for parts of the piping and HVAC systems was necessary on many floors.

During the second phase (currently in progress), GHAFARI continues to work with the selected subcontractors to advance the original BIM effort to install-level documentation. Despite liability concerns, and with support from the owner, the construction manager, and the general contractor, subcontractors were encouraged to work in 3-D and to deliver their data for coordination using 3-D systems whenever practical.

As a result, GHAFARI was able to leverage 3-D detailing efforts by the steel fabricator, the sheet metal contractor, and the piping contractors by directly interfacing with those subcontractor 3-D detailing systems. To complete the coordination process, GHAFARI’s BIM team augmented the sub contractor’s 3-D models for systems that were not provided by the sub-contractors in 3-D format, including electrical and fire protection systems, as well as a current architectural model from the various 2-D documents issued by the design team.

Conclusion

The early results from this project demonstrated that many potentially costly construction changes were detected and resolved very early during the bidding stages of the project, thus avoiding a likely increase in the construction schedule and budget.

Most notably, because of the early virtual coordination of all facility systems, changes were made to the structural steel packages that increased the available ceiling space for MEP systems to avoid potential conflicts with beams, bracing, and architectural components. In addition, as the effort continues and additional detail is provided to update the models during construction, the construction team is virtually coordinating the building and producing highly coordinated 3-Dbased installation-level documents that will significantly reduce the chances for field changes and associated schedule delays.

Samir Emdanat manages GHAFARI’s Advanced Technologies and leads the development and application of 3-Denabled lean design/delivery methodologies for GHAFARI business units. He directs the implementation of advanced technologies, including virtual factory, virtual reality, and design automation initiatives for a number of owners, including automotive, governmental, and hospitality, as well as contractors and architects/engineers. He can be reached at 1-313-441-3000.

Founded in 1982,GHAFARI is playing a leadership role in the deployment of 3-D Building Information Modeling (BIM) technology across the design/construction supply chain within the manufacturing, aviation, government, and commercial sectors. GHAFARI employs more than 1,300 architects, engineers, consultants, and staffing specialists from its Dearborn, Mich., headquarters and offices in Chicago, Indianapolis, Dallas, and Sacramento, Calif. For more information, visit www.ghafari.com.