We have a 600 mm wide free standing gas cooker sited in a 604mm gap between two fitted kitchen units. It is very old and needs replacing. My wife has selected a free standing dual fuel cooker (gas top, electric oven) which is 600 mm wide. Can I get a gas safe plumber to fit it in the existing 604 mm wide gap? I ask this question because a (non gas qualified) friend says that nowadays you need a space either side of the cooker. Many thanks for any replies.