Owner's Project Requirements Written After Design Is Half Done
A school district hires a Cx agent late. Schematic design is complete and design development is 60% done when the agent is engaged. The district has a one-page 'design narrative' from the architect that lists room counts and a target of LEED Silver but says nothing about ventilation effectiveness, humidity control for the gym and media center, or how the district's maintenance staff will operate the new DDC system. The mechanical engineer's basis of design (BOD) is a 40-page document that assumes a 24/7 occupied schedule for the media center and specifies a 55°F supply air temperature with reheat. The district's facility director mentions in passing that the media center is used only during school hours and that the current buildings run hot and humid in summer. The design team says the BOD is 'done' and asks the Cx agent to begin the design review next week.
1. What should the Cx agent do first, and why is the sequence important?
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The agent should not start the design review against the BOD as written. The owner's project requirements (OPR) are the yardstick for design review, and here the OPR does not yet exist in usable form. Reviewing the BOD first would implicitly adopt the engineer's assumptions, including the 24/7 media center schedule and the 55°F supply air with reheat, as if they were owner requirements. That inverts the process and makes the later OPR a rubber stamp.
The agent should convene the owner to develop a real OPR: measurable objectives for indoor environmental quality, humidity limits for the gym and media center, actual occupancy schedules, energy and water targets, maintainability and staff capability, and commissioning scope. The passing comment about summer humidity is a symptom the OPR must capture as a quantified requirement, for example a space humidity ceiling during occupied hours. Only after the OPR is agreed should the agent review the BOD for consistency with it. The 24/7 schedule assumption is a likely conflict that the review will surface, but it must be surfaced as a BOD-versus-OPR gap, not resolved by the agent's preference.
2. The design team argues that the late engagement means the OPR should just describe the design as it stands. How should the agent handle this?
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The agent should explain that an OPR written to match an existing design defeats its purpose and removes the owner's ability to detect design drift. The OPR is an owner document expressing what the building must do; the BOD is the engineer's response. If the OPR is reverse-engineered from the BOD, the design review becomes circular and the district loses the chance to catch the schedule and humidity assumptions before they are cast into construction documents.
The practical compromise is a two-part OPR: first, the owner's true functional and operational requirements, developed now with the facility director and maintenance staff; second, a documented reconciliation showing where the current design already meets them and where it does not. Any gap, such as the media center schedule or summer humidity, becomes a design review finding with a recommended resolution and an owner decision. Because design development is only 60% complete, there is still time to change the design at low cost, which is exactly the value the late-engaged agent should deliver. The agent should record the engagement timing and its consequences in the commissioning plan as a risk.