Base measurements should start around 15-by-15 feet for a comfortable gathering area.
An area rug should fit under at least two-thirds of a sofa to visually connect it to the room.
Wall-adjacent sofas should take up no more than two-thirds of the wall space against which they are placed.
Conversation areas should be approximately 10 feet across, with 15 to 24 inches in between each furniture piece to ensure a cozy arrangement.
Leave at least 36 inches of clearance in front of the hearth as a safety precaution.