Section 56(9)(c) in The M.P. Bhumi Vikas Rules, 1984
(c)If such interior or exterior open air space is jointly owned by more than one person, then its width shall also be as specified in Rules 59 provided that every such person agrees in writing to allow his portion of such joint open air space to be used for the benefit of every building abutting on such joint open air space and provided he sends such written consent to the Authority for record. Such common open air space shall thenceforth be treated as a permanently open air space required for the purposes of these rules. No boundary wall between such joint open air space shall be erected or raised to a height of more than 2.0 metres.