law: The Delhi Municipal Corporation Act, 1957
  Chapter XVI
  Building Regulations
  331. Definition.-
  In this Chapter, unless the context otherwise requires, the expression "to erect a building" means-
  (a) to erect a new building on any site whether previously built upon or not;
  (b) tore-erect.-
  (i) any building of which more than one-half of the cubical contents above the level of the plinth have been pulled down, burnt or destroyed, or
  (ii) any building of which more than one-half of the superficial area of the external walls above the level of the plinth has been pulled down, or
  (iii) any frame building of which more than half of the number of the posts or beams in the external walls have been pulled down;
  (c) to convert into a dwelling house any building or any part of a building not originally constructed for human habitation or, if originally so constructed, subsequently appropriated for any other purpose;
  (d) to convert into more than one dwelling house a building originally constructed as one dwelling house only;
  (e) to convert into a place of religious worship or into a sacred building any place or building not originally constructed for such purpose;
  (f) to roof or cover an open space between walls or buildings to the extent of the structure which is formed by the roofing or covering of such space;
  (g) to convert two or more tenements in a building into a greater or lesser number;
  (h) to convert into a stall, shop, warehouse or godown, stable, factory or garage any building not originally constructed for use as such or which was not so used before the change;
  (i) to convert a building which when originally constructed was legally exempt from the operations of any building regulations contained in this Act or in any bye-laws made thereunder or in any other law, into a building which had it been originally erected in its converted form, would have been subject to such building regulations;
  (j) to convert into or use as dwelling house any building which has been discontinued as or appropriated for any purpose other than a dwelling house.