Mixed-Occupancy Tenant Fit-Out and the Scope of the Alteration
A 1970s four-story office building (48,000 ft² conditioned) is being renovated floor by floor. On Floor 3, a tenant fit-out replaces lighting in 12,000 ft², adds a 6-ton packaged rooftop unit serving a new server room, and reconfigures two restrooms. The contractor argues the project is a 'repair and maintenance' action because the base building shell, envelope, and central plant are untouched, and that only the lighting replacement should trigger code review. The plans examiner notes the rooftop unit is new and the restrooms are being relocated off existing risers. The jurisdiction has adopted the current commercial energy code with no local amendments. The permit set is submitted as a single alteration permit.
1. How should the plans examiner characterize the project scope for energy code purposes, and what does that mean for which provisions apply?
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The action is an alteration of the space-conditioning and lighting systems, not mere repair/maintenance. Repair and maintenance is limited to replacement of components with same-capacity/same-efficiency equipment that does not increase connected load or change system type.
Because the fit-out (1) installs new mechanical equipment (the 6-ton RTU), (2) alters the lighting system over 12,000 ft², and (3) relocates plumbing fixtures served by service water heating, the applicable alteration provisions of the mechanical, lighting, and service water heating chapters each attach independently. The envelope is unchanged, so envelope alteration requirements are not triggered - but the examiner should confirm no new fenestration or roof work is hidden in the scope.
The correct framing: each altered system is evaluated on its own, and the 'shell untouched' argument is irrelevant to whether the mechanical and lighting alterations comply. The permit cannot be narrowed to lighting only.
2. The contractor proposes to keep the existing RTU-adjacent controls and simply tie the new 6-ton unit into the existing constant-volume thermostat. What is the examiner's likely position?
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New mechanical equipment must meet the controls requirements applicable to the system it serves, not just efficiency minimums. A new packaged unit added to an existing system generally must be provided with the required temperature control, setback/setup capability, and - where the system capacity and type cross the code thresholds - economizer and fan control provisions.
Key reasoning steps:
- Determine whether the new unit is a new system or an addition to an existing system; the code treats these differently for economizer and part-load requirements.
- The server room is a special occupancy load with high sensible heat ratio; the examiner should require documentation that the unit's control sequence and economizer (if required) won't compromise space conditions, or that an exception is properly claimed and documented.
- Tying into a single constant-volume thermostat without setback likely fails the control provisions regardless of unit efficiency.
The examiner should issue a comment requiring a controls narrative and either compliance or a cited exception.