Section 110(5) in West Bengal Municipal (Building) Rules, 2007
(5)Projections for shelves not exceeding 0.25 m (10') beyond the outer surface of external walls may be allowed within the minimum wider, narrow and back open spaces for the purpose of making wall cupboards or alcove, provided the thickness of the wall for such projections is minimum 108 brick work or 3' thick reinforced concrete.
