When I prepared my talks for REALCOMM this week, I had assumed that many of the attendees, active in REITS and large property managers, would be familiar with Building Information Models (BIM), and in particular the Nation BIM Standard (NBIMS) and buildingSmart. Regular readers are familiar with these, but because some new readers may be coming from the conference, I am going to review quickly why the property owner should know BIM, and demand buildingSmart.
The traditional business process is designed around delivery of hand drawn paper. CAD automates paper production, but not the completion of business process nor the tracking of deliverables. CAD only works for simple buildings, without fine tolerances and building controls. Because bits of information are spread over multiple two dimensional (2D) drawings, issues are not properly resolved in advance. Duct may be routed through a steal beam. Plumbing may block the telecommunications chase. Multiple utilities may not even fit above the dropped ceiling.
Capital projects need to adopt the disciplines and use of information technology adopted by manufacturing in the 80’s. It takes diligence, experience, and time, to catch these problems in a CAD project; in a large complex project, the task is too difficult. Usually they are caught during the construction process, creating additional expense in the form of change orders and construction delays. BIM is the answer.
Best Practices in Information Exchange relating to Capital Projects are codified in the National Building Information Model Standard (NBIMS). NBIMS aims to create a common standard for electronic exchange of all information associated with a building new or old to be able to use that information in all stages of the facility life-cycle. This information model allows the free flow of graphic and non-graphic information among all parties to the process of creating and sustaining the built environment.
Newly valued deliverables are not linked to traditional business process. For example, Energy Modeling, has no intrinsic link to design. The designer is not liable for it. Using BIM, energy models can be generated directly from the design, in effect commissioning the design before it goes to bid.
The following are symptoms of the poor information exchange using traditional design approaches:
- Failure to adequately integrated complex systems during construction process
- Late construction change orders
- Failure to hit Energy Modeling targets
- Difficult or undefined Commissioning targets
- Incomplete designs, especially of control systems, mean that there are many modifications during construction; these modification increase the cost of obtaining accurate as-built information.
- The many changes during construction make it difficult and expensivce to get as-built drawings of completed projects.
- Ill-defined and ineffective hand over of operating instructions mean that information is inaccessible.
NBIMS produces the following immediate benefits:
- Standardizes construction documents in line with national and international standards
- Models rather than draws buildings so problems are caught before construction, when they are cheap to ameliorate.
- Run Energy Models directly against Building Models to enable iterative energy analysis, even during value engineering
- Contractors are able to bid electronic Building Models, not the piles of paper.
ASHRAE has published the following numbers on the benefits of using a building model for construction.
Design:
- 20% to 50% reduction in Design Cycle Time
- 100% Accurate Procurement package
Construction:
- Time and Cost reductions 20% to 40%
- Reduced Rework
- Elimination of most change orders
Operation:
- Life-Cycle O&M reduction 10%-40%
- Reduced Handover/Turnover time