Section 143(2)(a) in Punjab Regional and Town Planning and Development Act, 1995
(a)to a building which was in existence, immediately before the date from which notification specifying the distance under sub-section (1) on either side of the road reservation of a by-pass or of a scheduled road not being a by-pass, has come into force, or, to any repair or erection or re- erection of such a building which does not involve any structural alteration or addition therein; or