Carroll County, MD Building Safety: Fire Sprinkler Requirements (2026)

3 states that in existing dwellings where accumulated refurbishment, renovation, or alteration affects the majority of either the structure's total square footage or existing finished space, then the entire structure and any additions shall be protected throughout with a sprinkler system installed in accordance with NFPA 13D. 4: an addition that includes a majority of the elements of a dwelling unit, such as bedrooms, bathrooms, kitchens, laundry rooms, HVAC, or water and sewer configuration, or that exceeds 50% of the structure's total square footage, must have NFPA 13D sprinklers installed within the addition.

In both the renovation and addition scenarios, the Building Official may grant an exception if emergency escape and rescue openings are installed throughout in accordance with the currently adopted code and the structure and emergency egress windows do not exceed one story above grade; for additions that exceed the 50% threshold, the Building Official can also approve construction without sprinklers after evaluating the scope of work and the level of hazard present. Sprinkler installation, like other work under Chapter 170, is reviewed and inspected by the Bureau of Permits and Inspections as part of the building permit process.