$re = '/\bfloor area:?\s*(\d+)/';
$str = 'A beautiful flat on the 3rd floor with floor area: 50 sqm and a lift
Newbuild flat. Floor Area: 30 sq.m","6 bed house with floor area 50 sqm, lot area 25 sqm
6 bed house with floor area 50 sqm, lot area 25 sqm';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php