Erwin Conrad Hock, 91, a retired Washington architect who during a career with private firms and the federal government designed and helped build residential homes, courthouses, post offices, schools and churches, died of pneumonia Sept. 3 at Sibley Memorial Hospital. He lived in Washington.

In addition to his work as an architect, he was a construction site engineer, a building contractor and federal construction analyst.

Mr. Hock retired in 1969 after a couple of years with the Washington architectural firm of Perkins and Will, where he was principally involved in the design of schools and churches in the Washington area. He spent the early part of the 1960s as an architect and construction expert for the Renewal Project Administration of the Department of Housing and Urban Development.

Earlier, he was a supervisory general engineer with the Public Buildings Service of the General Services Administration and, among other things, was responsible for assembling and compiling data used in the development of plans for federal construction projects.

Mr. Hock, a native of Belleville, Ill., was an architecture graduate of Washington University in St. Louis. In 1936, he came to Washington to work as an assistant architect for the Public Buildings Services.

He later became a project planner for the National Capital Housing Authority, and as a lieutenant commander in the Navy Reserve, he assisted the Bureau of Ships with the planning and construction of ship repair facilities during World War II.

After working for a prefab housing company in Columbus, Ohio, he took a job with a Washington architectural firm in 1948 and spent a few years as a self-employed contractor.

He was a member of the American Institute of Architects, the Construction Specification Institute and Metropolitan Memorial United Methodist Church in Washington.

Survivors include his wife of 63 years, the former Hortense Joseph, of Washington; two daughters, Joan Steyaert and Lynn Rhomberg, both of Bethesda; and a brother.