Guide · Specifications and drawings · 27 53 19.13

Check first responder distributed antenna system specifications against drawings

A first responder distributed antenna system riser can show donor antennas and amplifiers without confirming the coverage plan actually reaches every interior space the code requires, including the mechanical penthouse and below-grade storage a floor plan alone would miss. Review the coverage basis before treating the riser diagram as complete.

Trace the first responder distributed antenna system from the riser diagram into its coverage scope, signal strength basis, power and battery backup, and monitoring interface, then confirm donor antenna documentation before treating the design as coordinated.

Assemble the review package

Gather the DAS coverage and riser drawings, the donor antenna and signal-strength design analysis, the fire alarm monitoring interface documentation, electrical plans for the dedicated power circuit and battery backup, and the issued first responder distributed antenna systems specification. This system is distinct from the building’s general communications infrastructure or public-safety Wi-Fi; review the coverage areas the specification requires completely, not only the occupied floor plans.

WBDG publishes UFGS 27 53 19.13: First Responder Distributed Antennae Systems (DAS) as a public guide-specification reference (accessed September 26, 2026). Use your project’s issued specification and amendments for the actual comparison; the guide specification does not automatically govern your project. The checklist below is an original suggested review workflow, not a reproduction of the UFGS requirements.

Eight checks to run against the issued set

Use one record per location or system. The CSV contains the same eight prompts plus fields for source revisions, observed evidence, the review owner, the decision, and closure references.

Eight specification-to-drawing checksSwipe or scroll sideways to read all columns.
CheckSources to compareQuestion to resolve
Coverage scope by area typeSpecified NFPA 1221 complete-coverage requirement + building area plansDoes the DAS coverage plan actually include every interior area type the specification lists — mechanical areas, open stairwells, and storage areas — rather than only the occupied floor plans?
Frequency band and letters of permissionRiser/schedule frequency range + specified letters of permission for used frequenciesDoes the documented frequency range actually match the local first-responder radio system’s real frequencies, and does the submittal include the letters of permission the specification requires for each one, rather than a generic placeholder range?
Signal strength and reception basisDesign analysis and calculations + specified NFPA 1221 signal strength and reception criteriaDoes the submittal include an actual design analysis and calculation package for this building’s coverage areas, rather than assuming the specified minimum signal strength was met without site-specific analysis?
Power supply and battery backupElectrical drawings + specified primary/secondary power supply and UL 924 UPS requirementDo the electrical drawings show the dedicated circuit and UPS location the specification’s primary and secondary power supply requirements assume for the DAS head-end equipment?
System monitoring interfaceFire alarm/monitoring drawings + specified NFPA 1221 monitoring requirementDoes the fire alarm or monitoring system documentation actually show the trouble and supervisory signal interface the specification requires for a Two-Way Radio Communications Enhancement System, rather than treating the DAS as a stand-alone system?
Continuous duty environmental conditionsMechanical room plan + specified 24-hour, 365-day continuous duty designDoes the room housing the DAS head-end equipment have the ventilation and cooling the specification’s continuous 100 percent duty operation requirement assumes?
Donor antenna and signal-strength documentationSpecified detail drawing requirement + submitted design packageDoes the submitted design package actually include the required detail drawing showing donor antenna locations and site-specific signal strength for each donor system, rather than a generic system diagram?
Coordination with the separately specified fire alarm systemSpecified NFPA 72 reference + fire alarm system documentationIs the DAS coordinated with, but not substituted for, the separately specified fire alarm system, consistent with how other communications systems on this project keep their code-required systems distinct?

Worked example: a coverage plan missing the mechanical penthouse

Illustrative example: a DAS coverage plan and antenna layout are developed from the building’s occupied floor plans, and the design analysis documents signal strength for every tenant space. The mechanical penthouse and a below-grade storage room do not appear on the occupied floor plans used to develop the layout, so neither space received an antenna or a documented signal-strength reading, even though the specification requires complete coverage of mechanical and storage areas.

Compare the full building area list, including mechanical and storage spaces, against the DAS coverage plan, and ask the system integrator to extend the design analysis and antenna layout to the missing areas. Recheck the power and monitoring documentation for any added equipment before closing the item.

Avoid a false conflict

A DAS coverage plan built from the occupied floor plans alone can miss areas the specification still requires coverage for; mechanical areas, stairwells, and storage areas need to be checked against the actual building area list, not assumed from a tenant-space floor plan.

When requirements disagree, follow the project’s document-control and clarification process. Do not assume that drawings always override specifications, or the reverse. Identify the exact sources and request an authorized decision.

Close the issue across the affected documents

Record the location or tag, drawing and specification references, issue dates, observed difference, and the decision needed. Assign an owner and keep the item open until the response identifies the governing requirement. Check the revised drawings and specification references together; a response email alone may leave the issued package inconsistent.

For the overall process, use the guide to drawing and specification conflicts. Mark an inapplicable checklist row with a reason, and distinguish a verified correction from a question that still needs design information.

Where Groundbook fits

Groundbook’s drawing and specification review helps investigate potential disagreements in the documents you supply. Include the relevant specification sections and drawing references, then verify the cited evidence with the responsible reviewers before acting on a finding.

Questions, answered

FAQs

What should a first responder DAS document review compare?

Compare coverage scope by area type, frequency band and letters of permission, signal strength and reception basis, power supply and battery backup, system monitoring interface, continuous duty environmental conditions, donor antenna documentation, and coordination with the fire alarm system.

Does this checklist confirm the DAS meets its required signal strength?

No. It is a document-consistency review confirming the drawings and specification describe a matching coverage and design-analysis basis. Actual signal-strength testing and code acceptance remain with the responsible system integrator and authority having jurisdiction.

Is a first responder DAS the same as the building’s public-safety Wi-Fi or cellular DAS?

No. This system is dedicated to two-way radio communications for first responders under NFPA 1221 and is a separate system from any commercial cellular or Wi-Fi distributed antenna system serving the same building.

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