Galley Hatch Clearance

I'm planning for the galley hatch construction and will probably build it in place. What's a good amount of clearance to leave between the side of the inner galley wall and the side of the hatch. I've read anywhere from 1/8th inch
to 3/8 inch..... on each side...... any suggestions what others have done would be a helpful starting point.
thanks a lot.
John
to 3/8 inch..... on each side...... any suggestions what others have done would be a helpful starting point.
thanks a lot.
John