USGS ASCE 7 Seismic Design Values Lookup

Use this endpoint when you need official USGS-sourced ASCE 7 seismic design parameters for structural or geotechnical engineering work at a specific US location. Ideal for automating code-compliant seismic design checks, building permit preparation, or feasibility studies where Ss, S1, SDS, SD1, seismic design category, and PGA are required inputs. Prefer this over manual USGS web tool lookups when integrating seismic data into automated design workflows.

• Address not geocodable or outside the US — returns error indicating location not supported
• Invalid or out-of-range lat/lon coordinates — returns validation error
• Neither address nor lat/lon provided — returns missing required parameter error
• Unsupported ref_doc, site_class, or risk_category enum value — returns schema validation error
• USGS backend unavailable — returns upstream service error
• Payment not provided or insufficient — returns HTTP 402 Payment Required