{"nrhp_refnum":"10000812","name":"Olsen, Donald and Helen, House","other_names":[],"category":"building","location":{"address":"771 San Diego Rd","address_restricted":false,"city":"Berkeley","county":"Alameda County","state":"CA","lat":37.89618784600003,"lon":-122.27249352899997,"geom_source":"nps_gis"},"listed_date":"2010-10-01","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Architecture"],"significance_levels":["local"],"summary":{"what_it_is":"A single-family house at 771 San Diego Road in the North Berkeley hills, Alameda County, California, designed by architect Donald Olsen for his own family and built in 1954.","why_significant":"The house is significant at the local level under Criterion C as a pure example of the International Style of Modernism, at a time when the Bay Tradition prevailed in the region. It is considered the purest expression of Olsen's design philosophy, drawing on Gropius, Mies van der Rohe and Le Corbusier. Its steel-column structure, glass walls and flexible open plan are noted as uncommon for residential design.","narrative":"Perched on a wedge-shaped hillside lot beside John Hinkel Park in North Berkeley, this glass-walled house was designed by architect Donald Olsen for his own family and completed in 1954. Sixteen slender steel columns carry the structure and divide the plan into nine bays, so the exterior walls could be large glass panels and the interior could remain largely open. Moveable panels and sliding doors allow rooms to be reconfigured. The rear bedrooms are built into the slope, while the living areas project out over it. Painted white, the house contrasts with the surrounding trees. It was built economically from standard-sized materials of concrete, glass and wood. Olsen studied with Walter Gropius and worked in the International Style while most Bay Area architects favored the woodsy Bay Tradition. The house is recognized for its Miesian clarity and as the purest statement of his approach, and it was listed for its local architectural significance.","period_of_significance":"1954","architect_builder":"Architect: Olsen, Donald; Builder: Foster Willis","architectural_style":"Modern Movement / International Style","criteria":["C"],"status_note":"Still in use as a single dwelling; alterations include enclosed balconies, a lower-level studio (1994) and a small bathroom (c. 2003), which the form says do not compromise integrity.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:54:29.619435-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/10000812.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/10000812/e68fa22f29-800.webp","url_1600":"https://nationalhistoricalregister.com/media/10000812/e68fa22f29-1600.webp","licence":"CC0","author":"Derrick Coetzee (User:Dcoetzee)","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Donald_and_Helen_Olsen_House.jpg\" rel=\"noopener\">Derrick Coetzee (User:Dcoetzee)</a>, <a href=\"http://creativecommons.org/publicdomain/zero/1.0/deed.en\" rel=\"license noopener\">CC0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Donald_and_Helen_Olsen_House.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123858305","wikipedia":"https://en.wikipedia.org/wiki/Donald_and_Helen_Olsen_House","wikidata":"https://www.wikidata.org/wiki/Q5295337"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/alameda-county/olsen-donald-and-helen-house-10000812/"}