Information Management for Performance Metrics
Buildings often do not perform as well in practice as expected during pre-design planning, nor as intended by design. It is difficult to quantify the impacts and long-term economic implications of a building in which performance does not meet expectations. Current building construction and operational practices are devoid of quantitative feedback that could be used to detect and correct problems both in an individual building and in the building process itself.
A key element in this situation is the lack of a standardized method for documenting and communicating information about the intended and actual performance of a building. This deficiency leads to several shortcomings in the life-cycle management of building information. Planners do not clearly specify their expectations. Designers do not concisely document their design intent. Commissioning personnel have no standardized method for documenting the results of performance testing. Post-occupancy building performance cannot readily be compared to expectations in an attempt to evaluate and improve design and operation decisions. Last, without quantification of the magnitude of performance problems, it is difficult to motivate building process participants to alter their current practice.
We are currently developing two prototype tools intended to address this situation. Metracker is a tool for documenting and tracking performance metrics across the building life cycle. The Design Intent Tool assists owners and designers in identifying their design objectives for energy-efficient laboratories, and documents quantitative performance criteria for verifying that the objectives have been achieved.
Performance Metric Tracking with Metracker
A building project begins with a consideration of the various performance objectives of interest to building stakeholders (e.g., owners, designers, operators, occupants). A wide spectrum of objectives should be at least informally considered at this stage, including life-cycle economics; energy-efficiency; environmental impact; occupant health, comfort and productivity; and building functionality, adaptability, durability, and sustainability. Performance metrics can be used to explicitly represent these objectives, using quantitative criteria, in a dynamic, structured format that provides value across the life cycle of a building project. A guiding principle in defining a performance metric is to identify a critical variable that measures, reflects, or significantly influences a particular performance objective. To be useful across the building project life cycle, each metric must also be capable of being either predicted or measured at various stages of the project so that the achievement of each objective can be evaluated.
Metracker provides an environment for establishing a hierarchy of performance metrics and their benchmark values that document the intended performance of a building and its systems. During construction, these metrics aid the commissioning process by identifying what should be measured in the building, and what level of performance is expected for each measurement. Using Metracker to document the results of commissioning then provides an archive of measured building performance to support the detection and diagnosis of operation and maintenance problems. Metracker's data visualization facilities graphically display a history of intended and actual performance of a building across its life cycle. Metracker is based on the International Alliance for Interoperability's (IAI) Industry Foundation Classes (IFC), an evolving data model intended to facilitate the sharing of information between building industry software tools.
Design Intent Tool for Energy-Efficient Laboratories
A related tool that builds on the performance metric concept and tailors it to laboratory-type spaces, is the Design Intent Tool for Energy-Efficient Laboratories. This tool is designed to help owners develop and compile their anticipated performance objectives for laboratory spaces in a narrative, prose format to direct the design team's efforts. The design team can then use the tool to document their design concepts for approval by the owner and other designated stakeholders. In addition, the tool documents quantitative performance metrics that can be used to verify achievement of the objectives. The tool also provides a unique method to assist designers and energy consultants in identifying and applying advanced energy-efficiency features in laboratorytype environments by linking to a Design Guide for Energy-Efficient Research Laboratories. The Design Intent Tool is being codeveloped with Portland Energy Conservation Inc.
For more information, contact:
- Robert Hitchcock
- (510) 486-0884; fax (510) 486-0888
This work is supported by the U.S. Department of Energy, Laboratory Technology Research Program, the U.S. Environmental Protection Agency, Atmospheric Pollution Prevention Division, and the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Building Technology, State and Community Programs of the Federal Energy Management Program, and the U.S. Department of Energy. The Design Intent Tool work was supported by the California Institute for Energy Efficiency (CIEE) and the California Energy Commission (CEC).