Section 68(d) in Kolkata Municipal Corporation Building Rules, 2009
(d)In case of residential building only, the projections (overhang) of wardrobes, alcoves, cup boards and shelves shall be permitted at floor level upto 50 cm from the first floor level and above and provided the area of each such cupboard shall not exceed 2.0 sq. m. per habitable room and shall not exceed 3% of the respective gross floor area of the building of which such cupboards form a part. However in exterior open space this can be extended to 60 cm from first floor onwards for buildings having side open space more than 2.5 m.;
