Sprinkler an Enclosed Connecting Walkway?

10/30/2025

Are sprinklers required within an enclosed (conditioned) pedestrian walkway that connects two fully sprinklered buildings?

The walkway is 80 feet (25+ meters) wide and 26 feet (8 meters) above a roadway where vehicle loading and unloading may occur (temporarily parked vehicles are not considered storage).

Is the walkway considered an exterior projection from each connecting building, and since it is an occupied space, will sprinklers be required under the walkway structure?

Sent in anonymously for discussion. Click Title to View | Submit Your Question | Subscribe

10 Comments

Pete H

10/30/2025 06:01:04 am

From NFPA 13 (2016 edition)

8.15.7 Exterior Projections
8.15.7.1 Unless the requirements of 8.15.7.2, 8.15.7.3, or 8.15.7.4 are met, sprinklers shall be installed under exterior projections exceeding 4 ft in width.
8.15.7.2 Sprinklers shall be permitted to be omitted where the exterior canopies, roofs, porte cocheres, balconies, decks, and similar projections are constructed with materials that are noncombustible, limited combustible, or fire retardant treated wood as defined in NFPA 703, or where the projections are constructed utilizing a noncombustible frame, limited combustibles, or fire retardant treated wood with an inherently flame resistant fabric overlay as demonstrated by test method 2 in accordance with nfpa 701.
8.15.7.3 Sprinklers shall be permitted to be omitted from below the exterior projections of combustible construction provided the exposed finish material on the exterior projections are noncombustible, limited combustible, or fire retardant treated wood as defined in NFPA 703, and the exterior projections contain only sprinklered concealed spaces or any of the following unsprinklered combustible concealed spaces:
1) Combustible concealed spaces filledentriely with noncombustible insulation
2) Light or ordinary hazard occupancies where noncombustible or limited combustible ceilings are directly attached to the bottom of solid wood joists so as to create enclosed joist spaces 160 cubic feet or less in volume, including space below insulation that is laid directly on top or within the ceiling joists in an otherwise sprinklered attic.
3) Concealed spaces over isolated small exterior projections not exceeding 55 square feet in area.
8.15.7.4 Sprinklers shall be permitted from exterior exit corridors when the exterior walls of the corridor are at least 50 percent open and when the corridor is entirely of noncombustible construction.
8.15.7.5 Sprinklers shall be installed under exterior projections greater than 2 feet wide where combustibles are stored.

----

Okay, so due to the size of the enclosed space that is directly attached to at least one building, I don't see why this would not count as an exterior projection.

If it is all entirely noncombustible construction and there is no permanent storage, I'd say there's a decent argument to omit under 8.15.7.2.

8.15.7.3 doesn't apply (your walkway is too big and that's mostly for like attic doghouses)

8.15.7.4 doesn't apply cause you said enclosed.

8.15.7.5 ideally doesn't apply because you're arguing there is no permanent storage underneath.

Glenn Berger

10/30/2025 08:10:00 am

Depending on the applicable codes:

IBC 3104 could be applicable.

Todd E Wyatt

10/30/2025 08:21:07 am

IBC-2024 Section 3104 Pedestrian Walkways

Pedestrian Walkways (PW) is not considered part of either building it connects. An automatic sprinkler system (ASPS) is not required in a PW (regardless of the connected building ASPS requirements) although an ASPS can be utilized as part of an "alternative separation" (3104.5.2 & 3104.5.2.2) and as an exception to "3104.5.3 Open side on walkway" or as a requirement for non-fire-resistance rated protection of the intersection of the PW and the building(s) walls. Lastly, an ASPS affects the permitted exit access travel distances from the PW (3104.9).

Anthony

10/30/2025 08:19:37 am

A.8.15.7.2 Vehicles that are temporarily parked are not considered storage. Areas located at drive-in bank windows or porte-cocheres at hotels and motels normally do not require sprinklers where there is no occupancy above, where the area is entirely constructed of noncombustible or limited-combustible materials or fire retardant–treated lumber, and where the area is not the only means of egress. However, areas under exterior ceilings where the building is sprinklered should be protected due to the occupancy above.

Its a should not a shall so the use case needs to be observed. Also fire modeling needs to be considered if a wind tunnel effect will occur and improper sprinkler activation will be triggered (wind blows fire plume away from sprinkler over head). thus poor efficacy and poor uses case need would trigger a reasonable judgement to omit sprinklers.

If this is a walkway at a hospital, yes (mobility concerns). If its a walk way at a college less concerning as people in their 20's generally are a more mobile population.

Jack G

10/30/2025 08:42:23 am

Egress---sounds like its in the egress route.
Yes- protect if so.

franck

10/30/2025 10:58:11 am

I will give my point of view from a pure insurance perspective (which could be similar to AHJ).

1. I don't think, from your description, that the corridor is an emergency egress for any of the building. For that reason, it may not be necessary to provide sprinkler for life safety (but to be confirmed, as indicated by Jack and Anthony).
2. If there are fire doors on both sides of the corridor and the corridot itself is of noncombustible construction, and there is no combustible storage (at any time) in the corridor, then I would not ask for sprinkler protection inside the corridor.
3. If there are no fire doors, then I would ask for a sprinkler protection, as the fire from one building could spread via this corridor to the adjacent one (or at least spread heat and smoke from one building to the other one).

Chad

10/30/2025 01:59:46 pm

100% agree with Franck's assessment from an AHJ perspective.

Donnie

10/31/2025 06:24:33 am

Why not sprinkle throughout since the space is a conditioned space instead of looking for exceptions and assuming both buildings are sprinkled? I’m sure some small furniture will end up in the space or even trash cans. If it is required egress, I would suggest sprinkler protection since you cannot exit from a protected area into an unprotected or less protected area.

Anthony

10/31/2025 07:55:34 am

I wouldn't consider trash cans and or a lounge chair to change a room's designation from non combustible to combustible. Those are incidental items to the occupancy not a core feature of the occupancy. I would compare this for example to the volume of material needed to change from LH to OH1/OH2 say from an office to a mercantile low pile storage arrangement.

Though I would be excited to hear convincing arguments in the other direction :)

Todd E Wyatt

10/31/2025 08:19:30 am

The AHJ has a say as to what contents are permitted in a Pedestrian Walkway (PW) :

IBC-2024
Chapter 31 Special Construction
Section 3104 Pedestrian Walkways and Tunnels
3104.4 Contents
Only materials and decorations approved by the building official shall be located in the pedestrian walkway.

As to "why not sprinkler throughout" ... cost. The Codes are a type of "tax" on Building Owners that they must "pay" if they want a Certificate of Occupancy.

Sprinkler an Enclosed Connecting Walkway?

Leave a Reply.

ALL-ACCESS

SUBSCRIBE

COMMUNITY

YOUR POST

PE EXAM

FILTERS

ARCHIVES

PE PREP SERIES