Section R313 of the International Residential Code for One- and Two-Family Dwellings is hereby amended to read as follows:

SECTION R313

AUTOMATIC FIRE SPRINKLER SYSTEMS

R313.1 Townhouse automatic fire sprinkler systems. An automatic residential fire sprinkler system shall be installed in new townhouses containing three or more connected dwellings.

Exception: An automatic residential fire sprinkler system shall not be required where additions or alterations are made to existing townhouses that do not have an automatic residential fire sprinkler system installed.

R313.1.1 Design and installation. Automatic residential fire sprinkler systems for townhouses shall be designed and installed in accordance with Section P2904 or NFPA 13D.

R313.2 One- and two-family dwellings automatic fire sprinkler systems. Automatic residential fire sprinkler systems are not required in one- and two-family dwellings; however, systems may be provided on a voluntary basis.

R313.2.1 Design and installation. Where provided, automatic residential fire sprinkler systems for one- and two-family dwellings shall be designed and installed in accordance with Section P2904 or NFPA 13D.