Rule 544a. Section R302.2 of the code is amended to read as follows:
Exception: Where the building is provided with an automatic fire sprinkler system installed in accordance with NFPA 13D or P2904.1, a common 1-hour fire-resistance-rated wall assembly tested in accordance with ASTM E 119 or UL 263, as listed in chapter 44, is permitted for townhouses if such walls do not contain plumbing or mechanical equipment, ducts, or vents in the cavity of the common wall. The wall shall be rated for fire exposure from both sides and shall extend to and be tight against exterior walls and the underside of the roof sheathing. Electrical installations shall be installed in accordance with chapters 34 to 43. Penetrations of electrical outlet boxes shall be in accordance with section R302.4.
Mich. Admin. Code R. 408.30544a