Re: Townhouse Separation???
These townhouses are in blocks of 4 units and there will be a property line separating each unit.
This is why I asked. When I read the interpretations it is confusing to say the least as to why a property line makes a difference except for the one-hour versus two-hour requirement on the walls
CHAPTER 3
BUILDING PLANNING
SECTION R317.2
IRC Interpretation No. 75-06
2003 Edition
Issued: 04-18-2007
R317.2 Townhouses. Each townhouse shall be considered a separate building and shall be separated by fire-resistance rated wall assemblies meeting the requirements of Section R302 for exterior walls.
Exception: A common 2-hour fire-resistance-rated wall is permitted for townhouses if such walls do not contain plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. Electrical installations shall be installed in accordance with Chapters 33 through 42. Penetrations of electrical outlet boxes shall be in accordance with Section R317.3.
REFERENCED SECTIONS:
R101.2 Scope. The provisions of the International Residential Code for One- and Two-Family Dwellings shall apply to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, removal and demolition of detached one- and two-family dwellings and multiple single-family dwellings (townhouses) not more than three stories in height with a separate means of egress and their accessory structures.
Exception: Existing buildings undergoing repair, alteration or additions, and change of occupancy shall be permitted to comply with the International Existing Building Code.
SECTION R202 DEFINITIONS
LOT. A portion or parcel of land considered as a unit.
LOT LINE. A line dividing one lot from another, or from a street or any public place.
TOWNHOUSE. A single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from foundation to roof and with open space on at least two sides.
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Q: Is a common 2-hour fire-resistance-rated wall, in accordance with the exception to Section R317.2 of the International Residential Code, permitted for separation of individual townhouse dwelling units when separation incorporates a lot line between each townhouse dwelling unit?
A: Yes. The townhouse provisions in the International Residential Code are not based on the presence, or lack thereof, of either a property line or lot line between single-family dwelling units within a townhouse building. Section R317.2 requires separation by two 1-hour fire-resistance-rated walls with exposure from both sides, or by a common 2-hour fire resistance-rated wall per the exception.CHAPTER 3
BUILDING PLANNING
SECTION R321.1
IRC Interpretation No. 41-03
2000 Edition
Issued: 06-08-04
R321.1 Two-family dwellings. Dwelling units in two-family dwellings shall be separated from each other by wall and/or floor assemblies of not less than 1-hour fire-resistive rating when tested in accordance with ASTM E 119. Fire-resistance-rated floor-ceiling and wall assemblies shall extend to and be tight against the exterior wall, and wall assemblies shall extend to the underside of the roof sheathing.
Exception: A fire resistance rating of 1/2 hour shall be permitted in buildings equipped throughout with an automatic
sprinkler system installed in accordance with NFPA 13.
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Q: Is a two-family dwelling with a property line separating the dwelling units required to comply with the separation provisions in Section R321.1?
A: No. The code does not address a property line within an attached two-family dwelling. A dwelling is a building that contains one or two dwelling units. A building line, or property line, is a line established by law, beyond which a building shall not extend. An attached two-family dwelling with a property line between the two dwelling units is considered two separate buildings, located on two separate lots. Two individual dwellings must comply with the fire separation distance required in Section R302.1.
So why aren't townhouses consider seperate buildings when a property line divides them onto different lots?