Hardwired detectors with battery backup are required in Maryland homes. We install interconnected smoke and CO detector systems that meet Baltimore City and County code requirements.
Maryland requires smoke detectors on every level of the home, including the basement, and in every sleeping room. For homes built or substantially renovated after certain years, hardwired detectors with battery backup are required — battery-only units are not code-compliant in those situations.
Carbon monoxide detectors are required on each level of the home and within 15 feet of sleeping areas. Many homeowners use combination smoke/CO units to reduce the number of devices while maintaining full coverage.
Replace detectors over 10 years old. The ionization sensors inside smoke detectors degrade over time — an old detector may not alarm fast enough in a real fire. The manufacture date is stamped on the back of the unit.
A single hardwired detector installation runs $150–$200 depending on whether there's existing wiring at the location. Full-home systems (4–8 detectors, interconnected) are priced per unit with a discount for multiple units installed in one visit. We quote flat-rate before starting.
Hardwired detectors are connected to your home's electrical system and have a battery backup in case of power failure. They can be interconnected — when one detects smoke, all units in the home sound. Battery-only units are standalone and don't interconnect with hardwired systems. Maryland code requires hardwired units in most residential applications where wiring is being disturbed or new construction is involved.
At minimum: one on every level including the basement, and one inside or just outside each sleeping area. A typical two-story Baltimore rowhouse needs 4–6 detectors for full coverage. We assess your home layout and tell you exactly what's needed.
CO detectors are still recommended even in all-electric homes — CO can come from an attached garage (car exhaust), a portable generator, or a neighboring unit. Maryland code requires CO detectors in all homes with fuel-burning appliances or attached garages. If you're selling your home, CO detectors are a required inspection item in Maryland.