Before a single pipe is installed or a detector mounted, fire protection engineering drawings must pass regulatory review by the Authority Having Jurisdiction. Understanding what plan reviewers look for is one of the most valuable skills in the field.
What Is Plan Review?
Plan review is the formal process by which the Authority Having Jurisdiction (AHJ) — typically the local fire marshal, building department, or both — reviews fire protection engineering drawings and specifications before a permit is issued and construction begins. It is the regulatory checkpoint that ensures a proposed fire protection system meets the applicable codes and standards before it is built.
For building owners and developers, plan review is often experienced as a delay — a bureaucratic hurdle between design and construction. For fire protection engineers, it is something more fundamental: a peer review of the engineering by the authority responsible for enforcing the code, with real consequences for getting the design wrong.
What Gets Reviewed
Plan review for fire protection systems covers the complete design package, which typically includes:
Sprinkler System Submittal
- Complete scaled floor plans showing all sprinkler head locations, pipe routing, hangers, and control valves
- Riser diagram showing all system components from water supply through to the most remote heads
- Hydraulic calculation worksheets demonstrating adequate flow and pressure at the design area
- Water supply data (flow test results from field test or utility letter)
- Equipment cut sheets for all listed components (heads, valves, backflow preventers, fire pump if applicable)
- Specifications referencing the applicable edition of NFPA 13 and any local amendments
- PE stamp and signature (required in most jurisdictions for systems above a certain size)
Fire Alarm Submittal
- Floor plans showing all device locations with device types labeled
- Battery standby calculations demonstrating 24-hour standby plus 5 minutes of alarm for non-voice systems, or 24-hour standby plus 15 minutes for voice evacuation systems, per NFPA 72
- Voltage drop calculations for all notification appliance circuits
- Point-to-point wiring diagrams
- FACP cut sheets and programming documentation
- Sequence of operations describing all input/output control functions
The Plan Review Process Step by Step
Step 1 — Pre-Submittal Coordination
Experienced fire protection engineers engage with the AHJ before formal submission for complex or unusual projects. A pre-submittal meeting allows the engineer to present the design approach, identify potential code issues, and confirm the AHJ’s interpretation of ambiguous code provisions — before drawings are finalized and the clock starts running on plan review fees.
Step 2 — Formal Submission
The complete drawing package is submitted to the AHJ along with the required application forms and review fees. Submission requirements vary by jurisdiction — some AHJs accept electronic submissions; others require paper sets in specific formats. Incomplete submissions are typically returned immediately without review, resetting the timeline.
Step 3 — Review and Comment
The AHJ reviewer examines the drawings against the applicable codes. The reviewer is checking for:
- Code compliance — does the design meet minimum requirements?
- Completeness — is all required information present?
- Accuracy — are calculations correct? Are details constructable?
- Local amendments — does the design comply with jurisdiction-specific requirements beyond the model code?
When deficiencies are found, the AHJ issues comments — typically a written list of items that must be addressed before the permit can be issued.
Step 4 — Response to Comments
The engineer prepares a formal response to each comment, either revising the drawings to address the concern or providing a code-based justification for why the original design is compliant. Comment responses must be precise and thorough — a vague response invites a second round of comments and further delays.
Step 5 — Permit Issuance
When the AHJ is satisfied that all comments have been addressed, the permit is issued and construction can begin. The approved drawings become the construction documents — the contractor must build what was approved, not what is most convenient.
Changes made during construction that differ from the approved drawings require revised drawings and AHJ approval before implementation. “We’ll fix it on the as-builts” is not an acceptable approach — and it’s the kind of statement that leads to failed acceptance tests and certificate of occupancy delays.
Most Common Plan Review Comments
Experienced fire protection engineers anticipate and address common comment areas in the original submission. The most frequent AHJ comments on sprinkler and alarm submittals include:
- Insufficient water supply data — Flow test results expired (tests must typically be conducted within 1 year), or test conducted at insufficient proximity to the project
- Incomplete hydraulic calculations — Missing pipe schedule, incorrect Hazen-Williams C-factor, design area not identified on floor plan
- Missing coverage areas — Heads omitted in concealed spaces, closets, or other areas required by NFPA 13
- Insufficient battery calculation — Alarm load calculations don’t match the device count on the drawings
- Missing sequence of operations — Control functions (elevator recall, HVAC shutdown) not documented
- Non-listed equipment — Equipment specified that is not listed or approved for the application
After Permit: Acceptance Testing
Plan review approval is not the end of the regulatory process — it is the beginning of construction. When installation is complete, the system must undergo acceptance testing witnessed by the AHJ before it can be placed in service. Acceptance testing verifies that the installed system matches the approved drawings and performs as designed.
Common acceptance test failures — discovered at this late stage, after the contractor has been paid and the building is ready for occupancy — include systems that don’t match approved drawings, hydraulic performance that doesn’t match calculations (often due to substituted pipe fittings with different friction loss characteristics), and fire alarm devices that don’t respond as documented in the sequence of operations.
Conclusion
The plan review process is a quality control mechanism with real consequences — it is the reason that fire protection systems in new construction are designed, documented, and built to a consistent standard rather than assembled from whatever materials are on the truck. Understanding how the process works, what reviewers look for, and how to prepare complete and accurate submissions is one of the most practically valuable skills in fire protection engineering practice.
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Licensed in New York, New Jersey, and Virginia. Sprinkler systems, fire alarms, life safety analysis, plan review, and commissioning.
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