{"nrhp_refnum":"78000646","name":"Thorsen, William R., House","other_names":["Sigma Phi Place"],"category":"building","location":{"address":"2307 Piedmont Ave.","address_restricted":false,"city":"Berkeley","county":"Alameda County","state":"CA","lat":37.86892949600008,"lon":-122.25184245999998,"geom_source":"nps_gis"},"listed_date":"1978-11-20","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Architecture"],"significance_levels":["state"],"summary":{"what_it_is":"A shingled, L-shaped Arts and Crafts house at 2307 Piedmont Avenue in Berkeley, California, designed by Greene & Greene. The form gives 1909 as the specific date; a city letter says it was built in 1908 for San Francisco banker William R. Thorsen.","why_significant":"The nomination argues it is a fine example of Charles and Henry Greene's work and the only Greene and Greene building in Northern California that shows their fully developed bungalow style. It is one of six major designs from the peak of their careers. Its design and craftsmanship differ from their Southern California houses because it responds to Berkeley's climate, site and client.","narrative":"Set at the corner of Piedmont Avenue and Bancroft Way in Berkeley, this house was designed by the California architects Charles and Henry Greene and dated to 1909 in the nomination. It has an L-shaped plan, dark weathered wood shingle walls, a maroon clinker brick foundation and heavy timbers framing large windows and doors. Long sills and extended rafters give it a sense of elongation. Inside, Burmese teak paneling, oak floors and exposed joinery reflect the architects' craftsmanship. Alterations include an asbestos shingle roof added after the 1923 Berkeley fire, a porch enclosure by Charles Greene in 1927, and bathroom remodeling around 1945. The listing rests on its standing as the only fully developed Greene and Greene bungalow in Northern California and one of six major designs from the height of their careers. It shows how the architects adapted their vocabulary to Berkeley's climate and site, and offers a basis for comparison with their Southern California work.","period_of_significance":"1900-","architect_builder":"Greene & Greene, Architects.","architectural_style":"Greene and Greene \"bungalow style\"","criteria":[],"status_note":"Occupied; described as moderately altered and in process of restoration and adaptive use. Owned by an alumni association.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:55:31.74532-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/78000646.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/78000646/91a1c2e9d3-800.webp","url_1600":"https://nationalhistoricalregister.com/media/78000646/91a1c2e9d3-1600.webp","licence":"CC BY-SA 3.0","author":"Beerguy721 (talk)","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Thorsen_House.jpg\" rel=\"noopener\">Beerguy721 (talk)</a>, <a href=\"http://creativecommons.org/licenses/by-sa/3.0/\" rel=\"license noopener\">CC BY-SA 3.0</a>, via Wikimedia Commons","source_page":"https://commons.wikimedia.org/wiki/File:Thorsen_House.jpg"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123858353","wikipedia":"https://en.wikipedia.org/wiki/Thorsen_House","wikidata":"https://www.wikidata.org/wiki/Q7796737"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/alameda-county/thorsen-william-r-house-78000646/"}