Notwithstanding anything contained in this Act or in any other law relating to local authorities for the time being in force, or in any detailed development plan, made or deemed to be made under this Act, the Municipal Corporation of Chennai may sanction any buildings plan,-
(i) providing for the construction of more than one dwelling-house on any one site; or
(ii) providing for the construction of any building with variation in regard to requirement of plot extent or plot coverage or open space.