Architecturally, the Fenwick Historic District is composed largely of Shingle-style residences from early in the century. The Historic District comprises the bulk of the community, however some residences were built in the 1950s in a more modern style. Of the district's 60 main buildings, 17 represent examples of the Shingle style, with some others in Queen Anne or Victorian styles. Frequent features include gable-on-hip roofs that encompass side porches with minimalist wood bracing, creating a sense of heaviness characteristic of the Shingle style. Other frequently observed common architectural features include flares at the eaves of roofs, upper stories that overhang lower stories, and pent roofs over windows and doors. All of the three are typified in St. Mary's-By-the-Sea, a 1 and 1/2 story church building at 30 Agawam Avenue, designed by Francis Goodwin and built in 1883.