Section 141B(4)(a) in The Bombay Provincial Municipal Corporations Act, 1949
(a)in the case of residential buildings, having regard to the following factors, namely:-(i)the market value of the land in the area of the City in which the buildings are situated,(ii)the length of the time of the existence of the buildings.(iii)the type of the buildings, and(iv)whether the buildings are occupied by owners or tenants.