public function splitHouseNumber($houseNumber)
	{
		$houseNumberAddition = '';
		if (preg_match('~^(?<number>[0-9]+)(?:[^0-9a-zA-Z]+(?<addition1>[0-9a-zA-Z ]+)|(?<addition2>[a-zA-Z](?:[0-9a-zA-Z ]*)))?$~', $houseNumber, $match))
		{
			$houseNumber = $match['number'];
			$houseNumberAddition = isset($match['addition2']) ? $match['addition2'] : (isset($match['addition1']) ? $match['addition1'] : '');
		}

		return [$houseNumber, $houseNumberAddition];
	}