Section 4(5) in The Tamil Nadu Buildings (Lease and Rent Control) Act, 1960
(5)(a)The cost of construction of the building including cost of internal water-supply, sanitary and electrical installations shall be determined with due regard to the rates adopted for the purpose of estimation by the Public Works Department of the Government for the area concerned. The Controller may, in appropriate cases, allow or disallow an amount not exceeding thirty per cent, of the cost of construction having regard to the nature of construction of the building.(b)The Controller shall deduct from the cost of construction determined in the manner specified in clause (a), depreciation calculated at the rates specified in Schedule II.]
