Closets and Fire Sprinklers in New Jersey? Here’s what you need to know!

Written By Pedro Morejon

Understanding the Differences Between NFPA 13D, 13R, and 13

If you’re building or renovating a residential property in New Jersey, fire sprinkler requirements are an important part of code compliance—and closets are a key area that often raises questions. Whether or not a closet requires a fire sprinkler depends not only on its size and contents, but also on the type of sprinkler system installed. The three main standards—NFPA 13D, 13R, and 13—have different requirements, and understanding those differences is crucial.

NFPA 13D – One- and Two-Family Dwellings

In New Jersey, NFPA 13D applies to detached one- and two-family homes. Under this standard, sprinklers are generally not required in small closets (less than 24 square feet) unless they are under stairs or contain highly combustible materials. The intent of 13D is to provide life safety—not full property protection—so it allows some exceptions that reduce cost and complexity.

For example, a bedroom closet under 24 square feet constructed with gypsum board may not need a sprinkler under 13D. However, if the closet is in a location where fire could spread quickly—such as under a stairway or near a sleeping area—it may still be required.

NFPA 13R – Low-Rise Residential Buildings

NFPA 13R applies to multi-family residential buildings up to four stories, such as garden apartments or condos. This standard is more stringent than 13D but still focuses on life safety over property protection. In 13R systems, sprinklers are generally required in closets located within dwelling units, especially if they exceed certain size thresholds or store combustible materials.

Closets in common areas of the building—like maintenance or linen closets in corridors—are more likely to require sprinklers. The exact requirements can also depend on materials used and whether the closet is considered part of the unit or a shared space.

NFPA 13 – Commercial and High-Rise Residential Buildings

NFPA 13 is the most comprehensive sprinkler standard and is typically used in commercial buildings or high-rise residential properties. It provides full coverage for both life safety and property protection.

Under NFPA 13, most closets require sprinkler protection, regardless of size. This includes closets in dwelling units, under stairs, in corridors, and even mechanical closets. The standard has few exceptions, and those that exist are often dependent on fire-resistant construction and noncombustible contents. If the closet is over 12 inches wide, it will likely need coverage under 13.

New Jersey Code Enforcement

New Jersey follows the Uniform Construction Code (UCC), which adopts and modifies the International Building Code (IBC) and International Residential Code (IRC), along with relevant NFPA standards. Local building officials may interpret and enforce the rules with slight variations, so it’s critical to check with your local construction or fire subcode official to confirm whether your project meets the state’s and municipality’s requirements.

Key Takeaways:

  • NFPA 13D (One- and two-family homes): Sprinklers often not required in small closets.

  • NFPA 13R (Low-rise residential): Sprinklers required in closets in most cases, especially in common areas or larger closets.

  • NFPA 13 (High-rise and commercial): Sprinklers almost always required in closets, regardless of size or use.

When designing or renovating a building in New Jersey, understanding these differences can save time, money, and ensure the highest level of safety for occupants.

Pedro Morejon