In Maryland, carbon monoxide detectors are typically required in new dwellings under which conditions?

• A. In all single-family homes only
• B. In dwellings with fuel-burning appliances, attached garages, or multi-unit buildings
• C. In homes without garages
• D. In buildings taller than 20 stories

Answer: (B)

Carbon monoxide detectors are required in new Maryland dwellings when there are potential sources or pathways for CO to enter living spaces. The presence of fuel-burning appliances (such as gas furnaces, boilers, water heaters, or gas stoves) can produce CO, so detectors on or near living areas provide early warning. An attached garage creates a route for vehicle exhaust to seep into the home, making detection important. In multi-unit buildings, CO can migrate between units through shared walls or ventilation, so detectors help protect occupants in every dwelling unit. These risk factors—fuel-burning equipment, attached garages, or multiple units—drive the requirement because they present the strongest scenarios for CO exposure. Other situations, such as a simple single-family home without these features or a tall building not tied to these risk factors, do not define the typical trigger for the code in this context.