BIM and Tilt-Up: Working Together
By: Amy Numbers
Constructive Communication, Inc. anumbers@constructivecommunication.com
In today’s fast-paced and cost-driven construction environment, professionals in the architecture, engineering and construction (AEC) industry are constantly seeking techniques to increase project efficiency, decrease overall cost, improve the project delivery schedule, and generate the best product possible. One technology currently available to assist building professionals achieve these goals is Building Information Modeling (BIM). The term “building information modeling” (BIM) refers to a process for storing complete information about a building in a computer model. This information is then used in all aspects of building production from design decision making, production of construction documents and construction planning, and in the end, operation and management of the facility.
WHAT IS BIM?
Building information modeling techniques provide constant and immediate information on the project design, schedule and cost that is reliable, integrated and fully coordinated with the entire project team. Among the many advantages of BIM are increased speed of delivery of key project deliverables, better coordination efforts among all parties involved, and decreased cost due to reduction of errors.
The two key concepts of BIM are: 1) keeping all aspects of building design in digital form makes it easier to update and share information, and 2) creating real-time design data can save significant amounts of time and money and increase project productivity and quality. BIM also provides a digital picture of the building process to assist with the exchange and interoperability (the ability for complex systems to work together) of information in a digital format and data can be viewed as a 3D model or traditional 2D construction documents, depending on what the user needs.
BIM is designed to allow information to be handed from the design team (architects, surveyors, civil engineers, structural engineers, mechanical engineers, electrical engineers) to the contractor and subcontractors and then to the owner. Each team member can make their own changes and these revisions are tracked in a single source (model). The result will significantly reduce misinformation or information loss that occurs when a new team takes “ownership” of the project. Also, this system can greatly decrease errors made by the design and construction team with the use of conflict detection. In this process, the computer informs team members about parts of the building that are in conflict with each other and provides a thorough detailed computer visualization of each section in relation to the total building. As always, error reduction equals cost savings for all members of a project.
BIM BENEFITS AND THE BUILDING LIFECYCLE
The three major phases in the building lifecycle are design, construction and management. BIM can assist with the design phase by providing up-to-date design, schedule and budget information. In the construction phase, information about the schedule, cost and quality assurance can easily be accessed. Finally, the performance, utilization and financial information about the building can be retrieved using BIM over the building’s life.
During a project, an architect’s role is to balance the project scope, schedule and manage the cost. Any changes to these variables can cost time and money and possibly affect relationships with contractors and owners. Using traditional design methods, it is difficult to determine immediately how these changes
will affect the overall project cost and schedule because of the time and effort to manually make these calculations. However, using BIM methods, this critical information is immediately available, and project-related decisions can be made more quickly and effectively.
Building information modeling allows a project team to make changes to the project at any time during the design or documentation process easily allowing more time for the team to work on design and other architectural-related problems. In addition, all of the building design work can be done at the same time as project documentation, because all aspects of the design are captured upon creation and placed in the documentation as the work progresses and develops.
Whenever a change is made to a project, the effects of that change are automatically coordinated throughout the design. This allows the design team to deliver better work faster, because creating key project documents require less time and effort. This automatic coordination of changes that BIM offers eliminates coordination mistakes, improves the overall quality of the work and helps win repeat business.
In the construction phase of the building, BIM provides up-to-date information on building quality, schedule and cost. The builder can quickly analyze building status and produce updated estimates and construction scheduling, and the cost of proposed or procured products can be easily analyzed. Also, the builder can quickly prepare updated plans and documents for the owner, which means improved communications among both parties, and less time and money spent on construction administration issues because of more complete documentation and improved construction planning. The end result is that more of the owner’s money goes into the building itself and not overhead and administration issues.
In the management phase of the building lifecycle, BIM provides real-time information on the use or performance of the building; its occupants and contents; the life of the building over time; and the financial aspects of the building. A digital record of renovations is provided, which can assist with move planning and management in the event of occupancy changes.
BIM also accelerates the creation of standard building prototypes for different site conditions for various businesses, such as retail, that require the construction of similar buildings in many different locations (i.e. chain restaurants, etc.). Also, physical information about the building, such as finishes, furniture and equipment inventory, and financially important data are all more easily managed and available. Continual access to this type of information improves the owner’s revenue and cost management in the operation of the building.
BIM SHORTCOMINGS
While we have outlined the many benefits in the AEC community, BIM does have its shortcomings. The main difficulty is tied directly to its strength – collaboration. Our legal system is built around defined limits of responsibility and liability, but the collaboration aspect of BIM blurs these lines of responsibility. If many parties collaborate on a project and a problem occurs, who is responsible? Of course, these issues can be avoided or at least minimized by reducing the number of parties involved on a project. For example, a design-build project clearly defines responsibility because there is only one entity involved in the work. Because of this, many large design-builders have adopted BIM technology.
A cost/benefit analysis must also be conducted before an engineer implements BIM. Operational costs are increased as a firm must invest in new hardware and software, train its employees to use the new systems and possibly change work flow to use the systems effectively. Liability issues could arise because it may be difficult to determine where an engineer’s responsibility ends and from errors in the model or in translating information from the model.
Building information modeling will continue to have an increasing presence in the AEC industry as
it can greatly increase efficiency in the building process and can decrease problems by reducing inconsistencies and errors. However, those utilizing the technology must be knowledgeable of the benefits as well as the shortcomings in order to utilize it to the fullest extent to receive the greatest rewards.
BIM AND TILT-UP
Savvy Tilt-Up professionals have realized the benefits BIM can bring to projects and have begun incorporating it in their work. Two of the main benefits that BIM offers a Tilt-Up project are accuracy and speed. However, since Tilt-Up projects require attention-to-detail, it is critically important that even when using BIM, Tilt-Up professionals closely inspect for compatibility with other structural members. This extra attention will provide dividends as the project moves forward.
One example of BIM being used for a Tilt-Up project is a three-story office/retail building in Kansas City, Mo. The 66,900-square-foot facility is part of the Zona Rosa – Phase II Development and has retail on the first floor and office space on the second and third floors. The project was converted from conventional metal stud/brick veneer façade to Tilt-Up. The selling points for the conversion to Tilt-Up included a faster construction schedule and reduced cost.
According to Karen Hand, P.E., project manager and project engineer at Needham and Associates, Inc, BIM was a good choice to provide cost savings. “Our firm provided both the design and the detailing for the structure with our concurrent design and detailing process that uses our proprietary BIM software, BIG-DADi.”
For this particular project, the amount of intricate and complicated panel detailing required made the Tilt-Up portion best-suited to good old-fashioned hands-on detailing, she said. The project had innovative Tilt-Up details that were used to solve some unusual challenges on the project.
BIM provided great benefit to this project. “By using BIM not only for design but also to include the steel detailing, the shop drawing review process time was greatly reduced,” said Hand. “It allowed the steel detailing and Tilt-Up detailing to occur simultaneously and in a timely manner. By providing joist and deck lists for the vendor, considerable time was cut from the schedule.”
Since in some areas, BIM is in its infancy, there are many lessons to be learned from each project that incorporates it. The success of a BIM ultimately depends on what you want to achieve from its use. For example, Hand notes that on this project the architect created a BIM using REVIT to display the architectural features of the building and produced very detailed architectural drawings and 3D images for the client. However, all the data created an enormous file that served only his purposes. “Although this information is useful to the architect, our purpose was to produce fabrication shop drawings, said Hand. “Another separate BIM was produced to carry the information to the next level.”
For a project incorporating BIM to be successful, it is important that everyone is trained on the same software. Also, many of the BIMs created have extremely large files sizes, which make it difficult to share information among all the parties. While they are limitations to the software, it is clear that BIM is helping projects to get completed quicker and more accurately. Tilt-Up professionals have begun using BIM to further speed up the Tilt-Up design process and it is clear that BIM is here to stay.
