House at 511 Watertown Street
Why it's listed
Built in the late 1890s on a corner lot at Watertown Street and Broadway in Newton's Nonantum neighborhood, this house is a well-preserved example of Colonial Revival design. Water Department records show it was first connected to city water in April 1897, and construction was probably finished soon after. Its features include a bellcast hip roof with dormers, boxy massing, symmetrical window and door placement, and two-level bow windows on the front. The classical detailing is richer than that of comparable nearby houses, with Ionic corner pilasters, an entablature with enriched moldings, and a Palladian motif in the front dormer. The exterior has changed little since construction, aside from alterations to the front porch in the 20th century. The first owner was Morgan Mahoney, a Nonantum grocer, who lived in the house until his death in 1920. The architect is unknown. The house was listed for its architectural quality.
Significance in brief: The nomination calls it a well-detailed example of late 19th-century Colonial Revival architecture in Newton, with classical detailing more elaborate than nearby examples. Its exterior has survived with little alteration apart from the front porch. It is also tied to its first owner, Morgan Mahoney, a Nonantum grocer.
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 86001832, listed September 4, 1986. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence medium).
Key facts
| Address | 511 Watertown St., Newton |
|---|---|
| County | Middlesex County |
| Listed | September 4, 1986 |
| Reference number | 86001832 |
| Resource type | Building |
| Architectural style | Colonial Revival |
| Criteria |
|
| Areas of significance | Architecture |
| Level of significance | State, Local |
| Status (as stated in the nomination) | Condition is described as good; the house is still used as a residence, with a garage as an outbuilding. |
| Acreage | 0.3 |
| Coordinates | 42.35756, -71.20612 (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 86001832.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q14715587
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.