GovBot Structure Inventory
Read-only summaries of the U.S. Army Corps of Engineers National Structure Inventory (NSI 2026 Base) for an area: structure counts by occupancy and building type, foundation type, stories, floor area, housing units, model-based replacement-cost estimates and daytime and nighttime population estimates. No account or sign-in is required.
Source
- U.S. Army Corps of Engineers National Structure Inventory API (NSI 2026 Base; August 2025 price level; April 2025 population level; 2020 Census blocks).
- U.S. Census Bureau TIGERweb (Census 2020 layers): the name, land area and vintage of a county, census tract or block group requested by GEOID.
Each result states its source, dataset version and retrieval time. Results are computed from records read live from the NSI API and held for up to six hours to limit repeat requests.
Available operations
- Summarize the structures within a bounding box (up to 100 km²) or a radius of a point (up to 5 km).
- Summarize the structures in a 2020 county, census tract or block group.
- List a bounded sample of structure records near a point, with locations rounded and without value or population fields.
- List NSI occupancy codes, field definitions and documented limitations.
Areas with more than 50,000 structure records are not summarized in one request; tracts and block groups are smaller units. The MCP endpoint is https://structures.govbot.ai/mcp.
Scope and support
NSI is a modeled national inventory with known errors at the level of individual structures. Counts, values and populations are estimates. Values are replacement-cost estimates, not market values, and exclude land. The service returns no owner or address information and does not provide appraisals, insurance, flood-zone or eligibility determinations. GovBot is not affiliated with or endorsed by the U.S. Army Corps of Engineers, the U.S. Census Bureau or any government agency.
For support, corrections or accessibility requests, email hello@govbot.ai. Do not send confidential or sensitive personal information.