West Des Moines, IA Building Safety: Fire Sprinkler Requirements (2026)

City Code section 8-2A-12 amends IRC Section R313.2 (Single Family Dwellings Automatic Fire Sprinkler Systems) by adding Exception 2: an automatic residential fire sprinkler system is not required for a single-family dwelling containing less than 8,000 square feet of floor space, counting the garage, covered decks, covered porches and similar covered areas toward that total. The designer must document the square footage totals used to meet the exception directly on the building plans submitted to the Building Division. The same section amends the parallel IRC Section R313.1 (retitled to cover Townhouse and Two-Family Dwelling automatic fire sprinkler systems) with its own Exception 2, exempting a multi-unit building under 12,000 square feet from the sprinkler mandate where each unit runs from foundation to roof with open yard or public way on at least two sides and the shared walls between units carry either two one-hour fire-resistance-rated wall assemblies or a single two-hour rated assembly.

Above these square footage thresholds, or where the fire-separation and open-yard conditions are not met, the base IRC sprinkler mandate applies and a residential fire sprinkler system must be installed and inspected before occupancy. The Building Division, part of Development Services, reviews the plan documentation and inspects sprinkler installations where the exception does not apply.