Proposed quake standards could boost commercial construction cost
A new set of proposed earthquake construction standards would boost thecost of commercial construction by a third in Josephine County and elsewherein western Oregon, a Medford building official says.
The Structural Engineering Committee of the Oregon Building Codes StructuresBoard has proposed putting the westernmost edge of Oregon into seismic Zone4, the most restrictive of the state's classifications.
That area would include Josephine County, but not Jackson County.
The committee is holding a series of meetings on the topic along thecoast and in Southern Oregon this month. A meeting is set for 9 to 11 a.m.Nov. 19 at the Holiday Inn, 105 N.E. Agness St. (Exit 55) in Grants Pass.
The committee is seeking public comment on how the risk of a major earthquakeoff the Oregon coast should influence statewide building codes.
For building purposes, the state has six zones based on the risk of earthquakes.New construction in riskier zones must be built to withstand more seriousearthquakes.
Jackson County would remain in Zone 3, but the new standard puts JosephineCounty into Zone 4.
Zone 4 standards are comparable to fault zones in California,said Chris Reising, acting director of the Medford Building Safety Department.Several changes are involved, but it would increase the cost of newpublic and commercial buildings by about 33 percent.
Reising said residential construction and existing buildings wouldn'tbe affected.
Zone 4 also adds requirements for a dynamic analysis of anystructures to be built more than 65 feet tall.
That's much more involved, Reising said. It would requirea more intensive study of the geology and a more intensive study of thestructure.
Lands generally west of Interstate 5 are drawn into Zone 4 under theproposal.
It misses Jackson County, bisects Douglas and Lane counties andskips Washington County, Reising said. If you drew a line fromthe Columbia-Clatsop line south to the Jackson-Josephine county line, you'djust about have it.
Copies of an interim report and more information is available from JayBernards at (503) 373-1308 or Nanci Johnston at (503) 378-5838.