While we do not specify minimum room dimensions, the minimum distances between speakers should be maintained to create an accurate monitoring environment. For mixing non-theatrical Dolby Atmos content (i.e. music, home entertainment, gaming, podcasting, etc.), we recommend the following minimum distances between speakers as stated in the How to Design a Dolby Atmos Mix Room document:

Minimum distance between the side surround speakers (measured speaker baffle to speaker baffle)	3.0 Meters
Minimum distance between the center and line of rear-surrounds (measured speaker baffle to speaker baffle)	3.5 Meters
Minimum distance from the floor to the lowest overhead speaker (measured floor to speaker baffle)	2.4 Meters

Note that in smaller rooms where the recommended speaker layout dimensions cannot be achieved, a quality mix environment is still possible through careful speaker positioning and aiming.