The older the home, the better chance it contains some lead-based paint (LBP). A rule of thumb: built before 1950 -- probably LBP both inside and out. Between 1950 and 1960 -- probably LBP outside, maybe not inside. Between 1961 and 1970 --some chance for outside LBP, probably not inside. Between 1971 and 1978 -- slight chance of LBP. NOTE: though LBP was essentially banned in 1978, some existing LBP might have been used for two or more years afterwards (i.e., to 1980 or 1981). The only way to tell positively if you have LBP is to have it properly tested by a professional.