McElroy Octagon House
Also known as: Colonial Dames Octagon House
Why it's listed
Octagon House at 2645 Gough Street in San Francisco is an eight-sided, two-story building completed in 1861 for miller William C. McElroy and his wife Harriet. Originally built of concrete made from lime, cement and gravel, it is now covered in clapboards and topped by a small octagonal wooden cupola. Paired double-hung windows light each side, and a classical porch shelters the recessed entrance. The design follows the octagonal plan promoted by Orson Squire Fowler in his 1848 book, which argued that eight-sided rooms received more sunlight. At least five such houses once stood in San Francisco, and this is one of the last two and the only one open to the public. The McElroys lived here until 1891, and the poet Daniel O'Connell later lived in it for about three years, hosting writers and artists. In 1952 the Colonial Dames saved it from demolition, moved it across the street and restored it. It now serves as their California headquarters and a museum of 18th century furniture and manuscripts.
Significance in brief: It is an example of the octagon house fashion of the 1850s and 1860s, inspired by Orson Squire Fowler's 1848 book "A Home for All." Of at least five octagonal houses once in San Francisco, it is one of the last two and the only one maintained and open to the public. It was saved from demolition and restored in 1952.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · National Archives catalog entry. NRHP reference 72000250, listed February 23, 1972. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence high).
Key facts
| Address | 2645 Gough St., San Francisco |
|---|---|
| County | San Francisco |
| Listed | February 23, 1972 |
| Reference number | 72000250 |
| Resource type | Building |
| Period of significance | 19th Century (specific date 1861) |
| Architect / builder | William C. McElroy and wife (builders); restoration directed by Warren Perry, F.A.I.A. |
| Architectural style | Classical, influenced by Italianate |
| Areas of significance | Architecture |
| Level of significance | Local |
| Status (as stated in the nomination) | Occupied and in good condition; used as headquarters of the Colonial Dames in California and as a museum. It has been altered and moved from its original site. |
| Acreage | 0.2 |
| Coordinates | 37.79781, -122.42737 (NPS GIS) |
What listing means for this property
National Register listing is honorary for a privately owned home: it does not by itself restrict what an owner may do with their own money, and it does not require public access. Restrictions come from local landmark or historic-district ordinances, which are separate (how they differ).
Owner-occupied houses are not eligible for the 20% federal rehabilitation tax credit, which applies to income-producing buildings, but many states offer credits for homeowners. Listing also opens the door to preservation easements and to buying a plaque. Start with what listing means for homeowners, renovating a listed house and selling one.
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.
Sources and further reading
- National Park Service, National Register of Historic Places database (snapshot May 2026), reference 72000250.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q6801074
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.