§ 27-111 Continuation of lawful existing use.

The lawful occupancy and use of any building, including the use of any service equipment therein, existing on the effective date of this code or thereafter constructed or installed in accordance with prior code requirements, as provided in section 27-105 of article one of this subchapter, may be continued unless a retroactive change is specifically required by the provisions of this code.

§ 27-112 Change in occupancy or use.

Changes in the occupancy or use of any building may be made after the effective date of this code, subject to the provisions of section 27-217 of article twenty-two of this subchapter. After a change in occupancy or use has been made in a building, the re-establishment of a prior occupancy or use that would not be lawful in a new building of the same construction class shall be prohibited unless and until all the applicable provisions of this code and other applicable laws and regulations for such re-established occupancy or use shall have been complied with. A change from a use prohibited by the provisions of this code, but which was permitted prior to the effective date of this code, to another use prohibited by the provisions of this code shall be deemed a violation of this code.

§ 27-113 Continuation of unlawful existing use.

The continuation of the unlawful occupancy or use of a building after the effective date of this code, contrary to the provisions of this code, shall be deemed a violation of this code.

Article 4: Alterations of Existing Buildings

§ 27-114 Alterations of existing buildings.

Subject to the provisions of section 27-105 of article one of this subchapter, and except as otherwise specifically provided by the provisions of this code, the following provisions shall apply to the alteration of existing buildings, whether made voluntarily or as a result of damage, deterioration or other cause, provided, however, that the following alterations shall conform with the requirements of this code regardless of magnitude or cost:

   (a)   Alterations or additions to existing standpipes, sprinklers or interior fire alarm and signal systems or a change in use or an enlargement to spaces requiring such protection, as provided in subchapter seventeen of this code.

   (b)   Alterations, replacements or new installations of equipment for heating or storing water, as provided in reference standard RS-16.

   (c)   Projections beyond the street line, as provided in subchapter four of this code.

   (d)   Sprinkler, alarm protection, and emergency lighting requirements for places of assembly, as provided in subchapter eight of this code.

   (e)   Interior finish work, as provided in section 27-348.

   (f)   Finish flooring and floor covering, as provided in section 27-351.

   (g)   The installation or replacement of elevators, as provided in subchapter eighteen of this code.

   (h)   The installation, alteration or replacement of refrigerating systems as provided in reference standard RS 13-6.

§ 27-115 Alterations exceeding sixty percent of building value.

If the cost of making alterations in any twelve-month period shall exceed sixty percent of the value of the building, the entire building shall be made to comply with the requirements of this code, except as provided in section 27-120 of this article.

§ 27-116 Alterations between thirty percent and sixty percent of building value.

If the cost of making alterations in any twelve month period shall be between thirty percent and sixty percent of the value of the building, only those portions of the building altered shall be made to comply with the requirements of this code, except as provided in sections 27-120 and 27-121 of this article.