This article will cover which “outdoor” building portions are or aren’t considered part of the building and which are or aren’t subject to varying codes.

What is part of the building area?

Any area that is covered by a roof covering. So, this could include entryways/ driveway overhanging, covered patios, canopies, decks, porte-cocheres, other projections, etc.

The IBC defines building area as:

The area included within surrounding exterior walls (or exterior walls and fire walls) exclusive of vent shafts and courts. Areas of the building not provided with surrounding walls shall be included in the building area if such areas are included within the horizontal projection of the roof or floor above.

What is NOT part of the building area?

Any area that is open to sky. Also, a normal roof overhang of 1-2′ would not be considered an occupiable space and not subject to be considered part of the building area.

Generally, but not in all instances, a lattice/ trellis type of structure that is mostly open to sky would not be considered a roof covering, and also not make the area below a part of the building area. Additionally areas covered by umbrellas or shade providing canopies may not be considered part of the building area. Code commentary regarding building area elaborates : “

“This excludes spacesthat are inside this perimeter and open to the outside
atmosphere at the top, such as open shafts and courts “

The key is “open to outside atmosphere at the top”. This seems to be open to some interpretation, so it may depend on your local code official’s determination. A truly portable “umbrella” would almost certainly be exempt. A more permanent fabric type of shade structure may come under more scrutiny, depending on how large it is, and if it has openings or is fully covering/ permeability of fabric.

What are the code requirements for an outdoor area?

• Allowable area- If an outdoor area is determined to be part of the building area, it must then be considered in the code analysis and be included in the building’s “allowable area” calculations.
• Sprinklering- If the rest of your building is sprinklered, for whatever reason, then this outdoor area that is considered part of the building, and would be required to be sprinklered as well. In colder climates, this portion would need to be a “dry system” where the sprinkler pipes are not filled with water, but then get activated upon sensing heat and water is provided to them if needed. They are not continuously filled with water due to freezing concerns.
  • BUT, there is an important exception to sprinklering outdoor areas found in NFPA13:
    • NFPA13- 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 NFPA703, 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.
• Egress- Chapter 10 of the IBC is all about egress, which is getting occupants safely out of the building/ area in case of emergency/ fire. For an outdoor area that may be surrounded by railings/ partial walls, etc then this will essentially mean you must provide sufficient exit points for occupants to egress. If there is some elevation changes with steps/ stairs, then this chapter will also lay out requirements for those elements.
  • It is important to note, that even if an outdoor area is NOT considered part of the building area, but is occupiable then it would still be subject to the egress provisions of chapter 10. An example would be a patio area adjacent to a building that is totally open to atmosphere above. You certainly don’t need to consider allowable areas or sprinlering, but you do need to consider egressing out of this area if it is gated/ enclosed. Typically this means providing an exit or two out of the area. Exits, depending on the instance, may go directly to the outside or may be able to pass back through the building in some cases.
• Plumbing fixture calculations
  • Occupant loads for those on an open patio must be considered when calculating minimum plumbing fixtures for the building