Karpen House
Why it's listed
Built in 1955 on a two-acre lot carved from a former Lloyd Harbor estate, this single-family house is a long, low, flat-roofed home of wood frame construction clad in vertical cypress boards and battens. Morris Karpen, a trained draftsman and manufacturer of steel doors and windows, planned it himself and acted as his own contractor. Hicksville architect Keith Hibner adapted the plan from a vacation house by Pietro Belluschi that had appeared in a 1951 architectural magazine. The interior is open and zoned, with a service wing, a living-dining area, and a bedroom hall behind a Westchester granite fireplace wall. Large glass walls, cedar paneling, built-in storage and radiant floor heating reflect modern design ideas. Most original finishes and fixtures remain, including pink Formica kitchen features. The house was listed for its architecture and its record of how a middle-class family in the 1950s adapted modern design to suburban life on Long Island.
Significance in brief: The nomination argues the house is a representative, intact example of mid-twentieth century suburban residential architecture on Long Island, a vernacular interpretation of the modern style. It was adapted by owner Morris Karpen and architect Keith Hibner from a Pietro Belluschi vacation house published in 1951. It also documents post-World War II demographics, community development and middle-class expectations for suburban life.
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 06000643, listed July 26, 2006. Summary generated October 2026 (model claude-sonnet-5-5, prompt v1.0-2026-10-29, confidence medium).
Key facts
| Address | 3 Harbor Hill Dr., Lloyd Harbor |
|---|---|
| County | Suffolk County |
| Listed | July 26, 2006 |
| Reference number | 06000643 |
| Resource type | Building |
| Period of significance | 1955 |
| Architect / builder | Keith Hibner, architect; Morris Karpen, owner/contractor |
| Architectural style | Modern Movement |
| Criteria |
|
| Areas of significance | Architecture, Social History |
| Level of significance | Local |
| Status (as stated in the nomination) | Still used as a single residence; most original interior finishes, fixtures and furniture survive, with a 1965 greenhouse addition and some later updates. |
| Acreage | 2 |
| Coordinates | 40.89613, -73.45428 (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 06000643.
- Nomination form (PDF, National Archives) — catalog entry
- Wikipedia article (used for cross-checking only; text not reproduced here)
- Wikidata Q6373299
- This listing as JSON
Last updated October 2026. Found an error? See the editorial policy for how to report it.