Maui County, HI Building Safety: Fire Sprinkler Requirements (2026)

Section 16.25.405 applies only to hale, the Indigenous Hawaiian architecture structures that Article 4 of Chapter 16.25 allows under the Maui County building code. Table 405.1 sorts every hale into one of two fire protection classes by setback. Class A is a structure, or a group of structures, located at least 100 feet from any existing structure on the same or neighboring properties and at least 100 feet from any property line. Three adjustments apply. Where a property line abuts a public way, the 100 feet is reduced by the width of that way. A property line on the shoreline uses the shoreline setback. A hale ku'ai in the agricultural district that is under 200 square feet, completely open on three sides and used as an agricultural products stand needs only 15 feet from a property line that abuts a public way. Class A structures need no fire protection.

Class B is any hale that conforms to the zoning setbacks but fails the Class A test. A Class B hale must have an automatic fire sprinkler system, and an electrical permit is required for it. Section 405.2 sets the design standard at NFPA 13, then permits a hale-specific alternative. Flow is 18 gallons per minute for the first head covering up to 140 square feet of roof, plus 13 gallons per minute for each further head. Supply pressure at the base of the riser must be at least 40 pounds per square inch, residual pressure at the highest sprinkler at least 12, and head spacing cannot exceed 14 feet. Heads are open type with a 1/2-inch or 17/32-inch orifice and a wax corrosion resistant coating, no more than 6 heads can share a branch, and water density cannot fall below 0.10 gallons per minute per square foot.

The water source can be a domestic meter, detector check meter, underground well, storage tank, swimming pool or pond, but it must deliver 30 minutes of duration. Without a storage tank and booster pump, a 5/8 inch meter supports 1 sprinkler and a 3 inch meter supports 27. Piping is hard drawn copper or coated carbon steel, with plastic allowed only for below grade supply pipes. Smoke detectors at the highest roof points actuate the system, and a local alarm sounds from a smoke detector.