{"nrhp_refnum":"05000459","name":"Ayer, Frederick, Mansion","other_names":[],"category":"building","location":{"address":"395 Commonwealth Avenue","address_restricted":false,"city":"Boston","county":"Suffolk County","state":"MA","lat":42.34945207600006,"lon":-71.09032571522722,"geom_source":"nps_gis"},"listed_date":"2005-04-05","is_nhl":true,"nhl_designated_date":"2005-04-05","areas_of_significance":[],"significance_levels":["national"],"summary":{"what_it_is":"A five-story granite townhouse at 395 Commonwealth Avenue in Boston's Back Bay, Suffolk County, Massachusetts, built as a single-family residence for Frederick Ayer in the Neo-Classical Revival style. It was later joined to the neighboring building at 397-399 Commonwealth Avenue in 1971-72.","why_significant":"The mansion retains the only known examples of exterior ornament designed by Louis Comfort Tiffany still in place, in the form of glass and stone mosaic panels and banding on the granite facade. Its first-floor entry spaces, including the Marble Hall, mosaics, stained glass and a laylight, show Tiffany's residential design work. The property was designated a National Historic Landmark.","narrative":"Located on the north side of Commonwealth Avenue in Boston's Back Bay, this five-story granite townhouse was built as a residence for Frederick Ayer. Its Neo-Classical Revival facade is made of dressed granite with limestone trim, but the surface is enlivened by orange, red and gold mosaic panels and banding designed by Louis Comfort Tiffany. These are described as the only known Tiffany-designed exterior ornaments still in place. Inside, Tiffany's work is concentrated in the public entry spaces. The Marble Hall has white marble wainscoting and floors, glass mosaic borders, a semicircular stair beneath an apsidal arch, and a restored laylight above the imperial stair. A trompe-l'oeil glass mosaic peristyle highlights the stair. The private family rooms upstairs were treated in a restrained Classical Revival manner. The house was joined to its neighbor in 1971-72, its former Dining Room became a chapel, and it now serves as institutional housing. Its surviving Tiffany decoration is the main reason for its landmark designation.","period_of_significance":null,"architect_builder":null,"architectural_style":"Neo-Classical Revival","criteria":[],"status_note":"Currently used as institutional housing (Bayridge Residence and Cultural Center); joined to the neighboring building in 1971-72, with the former Dining Room converted to a chapel and some restoration work done in 2000 and 2002.","vacant_flag":false,"machine_generated":true,"model":"claude-sonnet-5-5","prompt_version":"v1.0-2026-10-29","generated_at":"2026-10-29 02:11:53.241504-05","source_pdf":"https://s3.amazonaws.com/NARAprodstorage/opastorage/live/71/7938/63793871/content/electronic-records/rg-079/NPS_MA/05000459_NHL.pdf"},"photo":{"url_800":"https://nationalhistoricalregister.com/media/05000459/984b8170e2-800.webp","url_1600":"https://nationalhistoricalregister.com/media/05000459/984b8170e2-1600.webp","licence":"CC BY-SA 3.0","author":"The original uploader was Swampyank at English Wikipedia.","credit_html":"<a href=\"https://commons.wikimedia.org/wiki/File:Fredick_Ayer_Mansion.jpg\" rel=\"noopener\">The original uploader was Swampyank at English Wikipedia.</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:Fredick_Ayer_Mansion.jpg"},"district":{"nrhp_refnum":"73001948","name":"Back Bay Historic District","url":"https://nationalhistoricalregister.com/districts/massachusetts/back-bay-historic-district-73001948/"},"sources":{"nps_snapshot_date":"2026-05-22","nara_catalog":"https://catalog.archives.gov/id/63793871","wikipedia":"https://en.wikipedia.org/wiki/Frederick_Ayer_Mansion","wikidata":"https://www.wikidata.org/wiki/Q5497305"},"indexable":true,"url":"https://nationalhistoricalregister.com/massachusetts/suffolk-county/ayer-frederick-mansion-05000459/"}