Cnopius House
Why it's listed
Built in 1896 at the corner of College Avenue and Orchard Street in Santa Rosa, this two-story wood house is a well-preserved Queen Anne design. Its multi-gabled roof, pedimented gable ends, dentils, and varied shingle patterns, including fishscale and scalloped types above shiplap siding on the first floor, give it a textured appearance. Spool and spindle trim decorates the recessed balcony, front porch, and rear veranda. A red brick chimney, a circular skylight over the upstairs stairway, and the original carriage house survive. John Cnopius, Jr. built the house on land that his father had purchased. The family came from Holland in the 1880s and ran a commission merchant and mercantile business dealing in farm products, groceries, hay, grain, wood, and coal until the 1930s. The Cnopius family sold the house in 1935-36 to the Cassani family. The property is recognized for its architectural quality and its link to a locally important merchant family.
Significance in brief: The nomination argues the house is an outstanding local example of late 19th century Queen Anne architecture, with high design quality and integrity. It is also directly associated with the Cnopius family, who were important local commission merchants in Santa Rosa.
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 82002277, listed April 12, 1982. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence high).
Key facts
| Address | 726 College Ave., Santa Rosa |
|---|---|
| County | Sonoma County |
| Listed | April 12, 1982 |
| Reference number | 82002277 |
| Resource type | Building |
| Period of significance | 1800-1899 |
| Architect / builder | J. Cnopius |
| Architectural style | Queen Anne |
| Areas of significance | Commerce, Architecture |
| Level of significance | Local |
| Status (as stated in the nomination) | Listed as occupied and in good to excellent condition; a 1981 city letter describes its restoration and use as law offices. |
| Acreage | 0.1 |
| Coordinates | 38.44534, -122.71370 (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 82002277.
- Nomination form (PDF, National Archives) — catalog entry
- Wikidata Q56561191
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.