SOURCE: Chief Appraiser Knowledge Base — Carbon Monoxide Detector Requirements Near Attached Garages and Fuel-Burning Appliances Compiled from: 2024 International Residential Code Section R315 (model code); Nevada Revised Statutes Chapter 477 (State Fire Marshal authority); Nevada Administrative Code Chapter 477; local jurisdiction fire code amendments (e.g. Southern Nevada Amendments to the International Fire Code); UL 2034 (carbon monoxide alarm listing standard); HUD Single Family Housing Policy Handbook 4000.1 (appraiser verification standard) Last reviewed: August 2026 ===================================================================== Carbon Monoxide Detector Requirements Near Attached Garages Carbon monoxide poisoning is a genuine, recurring cause of injury and death in homes with an attached garage or a fuel-fired appliance, which is why carbon monoxide alarms are one of the more consistently enforced life-safety items in modern residential construction. Unlike smoke detectors, which have a single long-standing national model code history, carbon monoxide alarm requirements are newer and are primarily driven by model building codes that individual states and local jurisdictions choose to adopt, rather than by a single nationwide federal statute. The model code standard: International Residential Code Section R315. The 2024 International Residential Code, Section R315, is the model code provision most states and local jurisdictions use as the basis for their own carbon monoxide alarm requirements. Under this model code framework, a dwelling unit is required to have carbon monoxide alarms where either or both of two conditions exist: the dwelling unit contains a fuel-fired appliance, such as a gas furnace, gas water heater, gas range, gas fireplace, or wood stove, or the dwelling unit has an attached garage with an opening that communicates with the dwelling unit, meaning a door, duct, or other opening that connects the garage to the living space rather than a garage that is fully separated with no connecting opening at all. Where alterations, repairs, or additions requiring a permit occur to an existing dwelling, the model code framework generally requires the dwelling to be brought up to the same carbon monoxide alarm standard as new construction, not just the specific room or system being altered. Carbon monoxide alarms under this framework are typically required to be interconnected with the dwelling's smoke alarms, to receive their primary power from the building wiring, and to have battery backup so they continue to function during a power outage. The actual alarm devices themselves are expected to be listed to UL 2034, the Underwriters Laboratories standard for carbon monoxide alarms,

interconnected with the dwelling's smoke alarms, to receive their primary power from the building wiring, and to have battery backup so they continue to function during a power outage. The actual alarm devices themselves are expected to be listed to UL 2034, the Underwriters Laboratories standard for carbon monoxide alarms, which governs sensitivity, alarm threshold, and device reliability testing. Why this is a model code matter rather than a single nationwide law. The International Residential Code is published by the International Code Council, a private code-development organization, and by itself has no legal force anywhere. It only becomes enforceable law once a state legislature, state agency, or local jurisdiction formally adopts a particular edition, often with local amendments. This means the exact carbon monoxide alarm requirement that applies to a given property depends on which code edition that property's state or local jurisdiction has adopted, and what amendments that jurisdiction made to the model language, not on the model code text itself. Nevada's adoption pattern. Nevada does not have a single statewide statute that independently mandates carbon monoxide alarms in every residential occupancy category the way some states do. Instead, Nevada Revised Statutes Chapter 477 gives the State Fire Marshal general authority over fire prevention code adoption and enforcement, and the practical carbon monoxide alarm requirement that applies to a given Nevada property is most often supplied through that property's local jurisdiction adopting International Residential Code Section R315 language, sometimes with its own local amendments layered on top, such as the Southern Nevada Amendments adopted for the Las Vegas metropolitan area. This means a Nevada appraiser or real estate agent should confirm the governing code edition and any local amendments with the specific city or county authority having jurisdiction over the subject property, rather than assuming one statewide rule applies everywhere in the state. Why carbon monoxide specifically, and why attached garages matter. Carbon monoxide is colorless, odorless, and non-irritating, which is exactly why it is so much more dangerous than a fire or gas leak that a person can see, smell, or hear before it becomes deadly. A running vehicle left idling in an attached garage, a malfunctioning gas furnace or water heater, or a blocked flue can all produce carbon monoxide that migrates from the garage or the appliance closet directly into living space through any communicating opening, including a door, an unsealed duct penetration, or shared framing

SOURCE: Chief Appraiser Knowledge Base — Automatic Garage Door Opener Entrapment Protection and Auto-Reverse Safety Requirements Compiled from: Consumer Product Safety Improvement Act of 1990 (Public Law 101-608); 16 CFR Part 1211, Safety Standard for Automatic Residential Garage Door Operators (Consumer Product Safety Commission); UL 325, Standard for Safety for Door, Drapery, Gate, Louver, and Window Operators and Systems; U.S. Consumer Product Safety Commission incident data Last reviewed: August 2026 ===================================================================== Automatic Garage Door Opener Entrapment Protection and Auto-Reverse Safety Unlike carbon monoxide alarms, which depend on which state or local jurisdiction has adopted which model building code, the requirement that an automatic residential garage door opener be able to detect an obstruction and reverse direction, commonly called auto-reverse, comes from a single nationwide federal safety regulation that applies uniformly across every state regardless of local building code adoption. This is one of the more clean-cut, unambiguous federal requirements a real estate agent or appraiser will encounter, in contrast to genuinely gray-area topics like unpermitted garage conversions. The federal legal basis. The Consumer Product Safety Improvement Act of 1990 directed the Consumer Product Safety Commission to require automatic residential garage door openers manufactured for sale in the United States to include entrapment protection. The Commission's implementing regulation, codified at 16 CFR Part 1211, Safety Standard for Automatic Residential Garage Door Operators, has required entrapment protection on every automatic residential garage door opener manufactured on or after January 1, 1993. This 1993 effective date is the single most useful practical marker: a garage door opener installed or manufactured before 1993 was not legally required to have auto-reverse protection at all, while any opener manufactured from 1993 onward is required to have it as a matter of federal law, not as an optional safety feature or a manufacturer's marketing choice. What the regulation actually requires: two independent protection systems. 16 CFR Part 1211 requires two separate and independent layers of entrapment protection, not just one. The first, called inherent primary entrapment protection under Section 1211.7, requires the opener's motor itself to sense resistance: if a closing door meets an obstruction, the operator must initiate reversal within 2 seconds of contact and return the door to the fully open position. This is a force-sensing protection built into the motor and drive mechanism itself, independent of any external accessory. The second layer, called secondary entrapment protection under Section 1211.8, is the mechanism most homeowners