I am currently having a 16KW stanby generator installed at the same time I'm finishing my basement. To get better coverage of protected circuits I'm planning on adding a sub panel to my 200 amp service that will be powered by the 50 amp circuit of the transfer switch. The closet that I've framed can meet code for the current panel plus the transfer next to it. My question: Is there any code requirement for space between panels? The top of the main panel meets the 66" rule. If I put the transfer and sub panel one above the other, next to the main panel, I can meet the 66" req. on top and the bottom is at 32". There is 1-2" between the sub/trans and main panels sides, and the same between the sub and trans panel top/bottom. If this isn't OK then I've got some reframing to do. Thanks in advance.