Glossary
OPR (Owner's Project Requirements)
Plain-Language Definition
A document that defines the functional requirements of a building project from the owner's perspective, including intended use, occupancy, environmental goals, and performance criteria.
Technical Context
The OPR is developed during pre-design and serves as the benchmark against which design decisions and commissioning tests are evaluated. ASHRAE Guideline 0 requires the OPR as the foundation of the commissioning process. It covers: building use and occupancy, indoor environmental requirements, energy goals, equipment and system expectations, building durability, sustainability objectives, and O&M staff capabilities. The design team responds with a Basis of Design (BOD) document.
Why It Matters
Without a documented OPR, there is no objective standard for evaluating whether a building meets the owner's needs. Design decisions become subjective, commissioning has no benchmark, and disputes about performance have no reference point. The OPR also drives value engineering decisions by clarifying which requirements are mandatory vs desirable.
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