{"nrhp_refnum":"05000731","name":"Condominium 1","other_names":[],"category":"building","location":{"address":"110-128 Sea Walk Dr.","address_restricted":false,"city":"The Sea Ranch","county":"Sonoma County","state":"CA","lat":38.67913448200005,"lon":-123.42878602099995,"geom_source":"nps_gis"},"listed_date":"2005-07-29","is_nhl":false,"nhl_designated_date":null,"areas_of_significance":["Architecture"],"significance_levels":["national"],"summary":{"what_it_is":"A ten-unit timber-frame condominium building at 110-128 Sea Walk Drive, The Sea Ranch, Sonoma County, California, designed 1963-64 by MLTW and built in 1965 by contractor Matt Sylvia.","why_significant":"The nomination argues it is among the most significant landmarks of post-war American architecture, quoted as 'the California architectural monument of the 1960s.' It showed how to build in harmony with the landscape using local vernacular forms and native materials. It was widely imitated, influencing cluster housing across the country, and won major awards including the AIA Twenty-Five-Year Award.","narrative":"Condominium 1 is a ten-unit, heavy timber-frame residential complex on a windswept bluff at the western end of Sea Walk Drive in The Sea Ranch, California. Designed in 1963-64 by the Berkeley firm MLTW (Charles Moore, Donlyn Lyndon, William Turnbull Jr. and Richard Whitaker) and built in 1965 by Matt Sylvia, it is clad in unstained redwood and topped with shed roofs, with units grouped around a shared courtyard. Its form was inspired by a weathered local barn and the site's former lumber settlement. Each 24-foot-square unit has its own relationship to the coastal views, and the bedrooms were conceived as two-story four-poster beds. The building drew national and international press soon after completion and earned several awards, including the AIA Twenty-Five-Year Award in 1991. It is credited with shaping cluster-housing design across the United States by blending local vernacular forms with modern planning. The building remains in residential use and retains its original character.","period_of_significance":"1965","architect_builder":"Moore, Turnbull, Lyndon, Whitaker (MLTW); built by Matt Sylvia","architectural_style":"Modern Movement/California Third Bay Region/Vernacular Shed prototype (post-1960)","criteria":["C"],"status_note":"Retains original integrity and has been maintained; units are privately owned and used as dwellings or rentals, managed by a homeowners association.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:54:29.794061-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/lz/electronic-records/rg-079/NPS_CA/05000731.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/05000731/38e8e59f21-800.webp","url_1600":"https://nationalhistoricalregister.com/media/05000731/38e8e59f21-1600.webp","licence":"CC BY-SA 3.0","author":"Sanfranman59","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Condominium_1,_110-128_Sea_Walk_Dr.,_Sea_Ranch,_CA_7-5-2010_7-07-18_PM.JPG\" rel=\"noopener\">Sanfranman59</a>, <a href=\"https://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:Condominium_1,_110-128_Sea_Walk_Dr.,_Sea_Ranch,_CA_7-5-2010_7-07-18_PM.JPG"},"district":null,"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/123862054","wikipedia":"https://en.wikipedia.org/wiki/Condominium_1","wikidata":"https://www.wikidata.org/wiki/Q5159315"},"indexable":true,"url":"https://nationalhistoricalregister.com/california/sonoma-county/condominium-1-05000731/"}