other by wall and/or floor assemblies having not less than a 1-hour fire-resistance <br />rating when tested in accordance with ASTME 119 or UL263. <br />We are proposing that the floor-ceiling assemblies between stacked flats be 2- <br />hour assemblies to exceed the 1-hour minimum requirement; and, as per <br />R302.3:1, the supporting construction of the floor assemblies to also exceed the <br />30-minute assembly minimum (of not less than 1/2-inch gypsum board) also by <br />providing 2-hour construction at structural framing supporting the floor-ceiling <br />assemblies. Note: it's important to point out that.the proposed 'stacked flats as <br />standalone buildings also meet all the other requirements for two-family <br />dwellings as defined in the ORSC. <br />To supplement the proposed 2-hour walls and the 2-hour floor-ceiling assemblies <br />between the single and two-family dwellings, we are also proposing a NFPA 13D <br />sprinkler system throughout the single and two-family dwellings. With the <br />introduction of the 13D system at the dwellings, we're proposing to exceed the <br />minimum code requirement of having to provide only 1-hour partition walls and <br />30-minute floor-ceiling assemblies. By doing this, our proposal offers 2-hour fire <br />areas WITH sprinklers throughout the dwelling units to enhance the safety of the <br />occupants. This is consistent with table R302.1, that requires walls to be 1-hour <br />rated if the fire separation is less than 3 feet. <br />We believe that by doing all this, we are consistent with and meet the intent of <br />• R302 / Fire-Resistant Construction, and the Oregon Residential Specialty Code. <br />Through the use of 2-hour fire separations between all residential buildings and <br />all dwelling units, combined with NFPA 13D fire sprinklers, we believe we are <br />proposing an increased level of fire protection and occupant safety than would <br />have been otherwise provided by meeting the minimum fire assembly <br />requirements of the ORSC or the OSSC for this building configuration. <br />Sincerely, <br />c~ <br />Willard C. Dixon, AIA <br />Project Manager <br />Oakleigh Meadow Cohousing <br />wcd@willardedixon.com <br />P_J <br />-2- <br />298 289 <br />409 <br />