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It varies by state, but in Maryland, new construction requires it, and older houses are required to install detectors with sealed-in, long-life batteries or AC
by flatline 13y ago
It varies by state, but in Maryland, new construction requires it, and older houses are required to install detectors with sealed-in, long-life batteries or AC detectors by 2018:
http://mgaleg.maryland.gov/2013RS/fnotes/bil_0009/sb0969.pdf http://mgaleg.maryland.gov/2013RS/fnotes/bil_0009/sb0969.pdf