(1) Subject to the prohibitions and restrictions in the condominium documents, a co-owner may make improvements or alterations within a condominium unit that do not impair the structural integrity of a structure or otherwise lessen the support of a portion of the condominium project. Except as provided in section 47a, a co-owner shall not do anything which would change the exterior appearance of a condominium unit or of any other portion of the condominium project except to the extent and subject to the conditions as the condominium documents may specify.

  (2) If a co-owner acquires an adjoining condominium unit, or an adjoining part of a condominium unit, then the co-owner may remove all or part of an intervening partition or create doorways or other apertures therein, notwithstanding that the partition may in whole or in part be a common element, so long as a portion of any bearing wall or bearing column is not weakened or removed and a portion of any common element other than that partition is not damaged, destroyed, or endangered. The creation of doorways or other apertures shall not be deemed an alteration of condominium unit boundaries.