Mount Prospect, IL Building Safety: Fire Sprinkler Requirements (2026)

Section 24.202 sits in Chapter 24 of the Mount Prospect Village Code, and § 24.201 makes the Fire Official responsible for enforcing the installation, testing, maintenance and modification of fire suppression systems. Subsection B requires sprinklers in every building or area specified in the International Fire Code, the International Building Code and the Village's own list. The first item on that list is the broad one: every newly constructed building, structure or portion of one, regardless of occupancy classification, construction or square footage. Subsection A adds that where the adopted codes conflict, the most restrictive provision applies.

Subsection C sets the design rule. Systems follow NFPA 13, unless the section modifies it, but NFPA 13D systems are permitted in single-family attached and detached homes, townhomes and manufactured occupancies, and NFPA 13R designed systems are not permitted at all. Subsection D.3 adds that when sprinkler protection is required in a single-family home, townhome or manufactured home, at least one fire sprinkler must cover the garage area.

The Residential Code amendment in § 21.106 (section P2904.1) points the same way. Residential systems are designed to NFPA 13D or to Section P2904, which the Village treats as equivalent. Partial systems are allowed only in single-family detached houses that meet the Village's definition of a Limited Residential Fire Suppression System. That definition requires type-x fire rated gypsum board throughout the structure, dimensional lumber framing with no open web or solid web engineered floor or roof trusses (engineered beams, posts and headers are allowed), and residential sprinkler heads in the kitchen and in any mechanical closet or area holding a furnace or water heater.

Existing houses get a carve-out. Under § 24.202(B)(2), single-family attached and detached homes, townhomes and manufactured homes are excepted from the retrofit triggers for an increased fire area and for an addition of any size.