Forest Grove's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Forest Grove is Category D. High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. Nationally, Forest Grove ranks above 88% of the 4,875 cities in this dataset for seismic hazard - the 88th percentile.

Forest Grove by the numbers

USGS's underlying values for Forest Grove: 0.43g peak ground acceleration, 0.924g at short period, 0.454g at 1 second. Within Oregon alone, Forest Grove ranks 15 of 80 cities by seismic hazard - the 82th percentile in-state. Forest Grove has a population of about 27,076.

What a retrofit costs in Forest Grove

A full earthquake retrofit typically runs $5,000-$10,000 nationally (around $7,000 typical), driven mainly by house size and foundation type, not by Oregon specifically. California's Earthquake Brace + Bolt grant, which covers a large share of this cost, is a California-only program and does not apply in Oregon.

Insuring against this, not just retrofitting

A Forest Grove homeowner cannot buy a standalone earthquake policy in most cases - it is added to an existing homeowners policy as an endorsement, so the place to start is a regular home-insurance quote.

Where Forest Grove's figures come from

Forest Grove's Category D and every number above trace to USGS's own ASCE 7-16 Design Maps service - see the methodology guide. See the category explainer for what Category D does and doesn't tell you about Forest Grove.