Section 3(1)(b) in The Gujarat Slum Areas (Improvement, Clearance and Redevelopment) Act, 1973
(b)that the buildings in any area, used or intended to be used for human habitation are-(i)in any respect, unfit for human habitation; or(ii)by reason of dilapidation, overcrowding, faulty arrangement and design of such buildings narrowness or faulty arrangement of streets, lack of ventilation, light or sanitation facilities, or any combination of these factors, detrimental to safety, health or morals.