BIM Software Offers Wealth of Design Information
By Loren Snyder October 2006 - Software
The construction industry is one of the last points of resistance to automation. It’s an industry where the majority of work is performed by hand, not by a computer. And even when builders, facility executives and operational personnel use computers, the information often winds up on paper, not in a database. But the increased ability to model a structure using three-dimensional modeling software promises to shift that paradigm.
What’s driving the change is known as Building Information Modeling (BIM) software, which acts as a single-source repository for information about a building. Unlike other facility management aids, such as CAD or CMMS systems, BIM software is designed to integrate every aspect of a building.
Although the concept of BIM isn’t exactly new, the software that’s been developed to model buildings is only in the early stages of use and the full potential has not yet been exercised. Even so, the models are providing several cost-saving benefits during the design and construction phase of building projects — reducing change orders, for one.
Those most closely allied with BIM development are now working to standardize BIM connectivity with existing facility management technology. Doing so would allow the models to retain usefulness for the duration of a building’s life, from design stage to demolition.
Where It’s at Now
There are three main types of BIM renderings, according to Andy Fuhrman, CEO of the Open Standards Consortium for Real Estate (OSCRE).
The most rudimentary is the massing model. It uses a series of dimensional figures — blocks, tubes, cones and other shapes — with few or no architectural details. As with all building information models, the information is assimilated from various sources to avoid delays and costly conflicts during the preliminary construction phase.
“They’re used by general contractors who wish to plan their construction sequencing and site layout,” says Fuhrman. “Imagine the delays possible if contractors place a tower crane where the main sanitary sewer line needs to be excavated.”
Floor-by-floor structural components can also be added to this model, as well as a link to a project schedule. Fuhrman says a BIM's role is to help construction superintendents, schedulers, modelers and subcontractors all work together to develop a strategy before any equipment shows up on the jobsite. Ideally, when the job begins, the stakeholders understand the project’s sequencing and staging, thereby reducing project delivery times, risk, costs and potential lawsuits.
Graphic BIM renderings are a step up in complexity from massing models. These add photorealism to the model and allow greater understanding of the project by owners or occupants than two-dimensional schematics.
“These models can produce virtual ‘walk-throughs’ and 360-degree rotating views,” says Fuhrman. “They’re more advanced, and can represent building system components, such as light fixtures, fire-rated wall systems, and other real-world building components, including mechanical, electrical, and plumbing routing.”
Finally, there are optimized three-dimensional BIM renderings which, like the graphic versions, are photorealistic; but the optimized three-dimensional versions also can contain individual object information. In other words, each air handler could be labeled. Make, model, serial numbers, warranty information, maintenance records and more could be stored for individual devices. This is where the full potential of BIM can be realized.
What the Future Holds
For everyday facility management, the prospect of software that integrates all knowledge about a building would create substantial efficiency and economic gains — at least in an ideal world.
“The key element here is that the BIM model must be kept alive after the model is handed over to the facility owner or manager,” says Dana Smith, chairman of the U.S. National Building Information Model Standards (NBIMS) committee. “You can’t just archive it, and you can’t just forget about it, or the information will die and be rendered almost useless.”
To use a BIM system successfully, the human element cannot falter. Although automated updates can be used, they’re not available in all instances. Manual data entry is frequently necessary to maintain the most up-to-date information in the models. The model would also need to be appropriately linked to other building software.
In some ways, the potential for BIM use is limitless. In theory, for example, it would ease the permitting process by automatically reviewing a design and comparing it to code, something the International Code Council is currently addressing.
“With automated plan reviews, one can envision a much shorter turn-around for review and construction approvals,” says David Conover, senior advisor for the International Code Council. “Ideally there will be ‘interoperable building regulations’ and building information models available in the future to facilitate more timely and accurate review and approval to construct.”
Because of digitization, BIM will be able to cross-reference compliance codes with building item placement. For example, building information models will be able to check bathroom accessibility.
“Grab bars could be checked for their relationship and distance with the floor and toilet,” says Fuhrman. “The toilet could be checked for its distance from the wall, grab bars, sink, partitions and toilet paper dispenser to help ensure compliance.”
The software could be configured so that architects or other designers would be prevented from placing non-rated doors, glazing, mechanical, electrical or other elements in fire-rated walls and assemblies. It can also issue warnings whenever building components are placed in ways that nullify codes or permitting regulations.
What It’ll Take to Get There
The National Institute of Building Sciences is working on a BIM standard known as NBIMS, the national building information model standard. Smith, who chairs the committee working on the standard, hopes to have a preliminary set of standards in place by the end of this calendar year. Standardizing the data used by BIM would make possible many of the ideals behind BIM’s original intent.
Even with preliminary standards, BIM won't be adopted overnight. Some standardization is required to make BIM a reality.
Smith is working with the International Alliance for Interoperability (IAI) in its effort to develop industry foundation classes, which apply universal taxonomy and nomenclature to building components and will help simplify interoperability of systems and software within a BIM.
Also working with IAI is Vladimir Bazjanac, a researcher at Lawrence Berkeley National Laboratory. He’s attempting to smooth the integration of data from other facility management sources into building information models.
“Traditionally, users of HVAC design and simulation tools have had to manually transcribe information from other sources,” Bazjanac says. “Such transcription and duplication of data often delays productive work and results in numerous errors and omissions.”
Bazjanac has created a preliminary data model for BIM that shares data for HVAC systems. “The data model is still under development, but its latest version — IFC2x2 — is the first IFC version that supports data exchange and sharing among tools used downstream in the building procurement process,” he says.
While not perfected, the standardization continues to progress at a very rapid rate.
“The intent,” says Fuhrman, “is to evolve the practice beyond today’s capabilities, so that the model and its associated data could be handed over to the owner, operator or investor for easy integration with current integrated workplace management systems, finance, security or building automation systems.”
Benefitting From BIM
“Change orders can typically run up the cost of new construction by as much as 10 percent,” says Smith. “BIM software typically accounts for less than one percent of a new building’s cost, and in several instances has completely eliminated change orders during building construction.”
In one recent construction project by DPR Construction for example, BIM was a tiny fraction of the total building cost. The construction cost of the 1.2 million square foot project was in excess of $100 million, yet change orders were nearly nonexistent. BIM represented .04 percent of the total construction cost.
Smith, who also works with the Department of Defense, gave an example of the value of BIM for disaster recovery, citing the damage sustained by the Pentagon on Sept. 11, 2001.
“When the Pentagon was struck, water mains were broken,” he says. “But they also had to shut off the power, because of the standing water.”
The recovery effort was complicated because the plans had to be found for both water and electrical lines, and then individual valves — in the case of the water mains — had to be located before they were turned off.
“With a building information model in place,” Fuhrman says, “things would have gone much more quickly.”
The key to using BIM successfully is, as Smith says, “keep it alive.”
“An effective BIM stays with the building and additional information is added as the building is used and maintained,” says Conover. “Because some of that information is relevant to fire protection, continued permitting of the building, or to operations and maintenance, the BIM can more easily evaluate conformance with regulations.”
The potential benefits of BIM for facility executives are many. As Conover says, “retention of and access to critical information will lead to better and safer buildings.”
CASE IN POINT
Loren Snyder is a freelance writer and former managing editor for Building Operating Management.