Upon the completion of their new home, Brattleboro's Baptists boasted of having “the most costly and elegant specimen of church architecture this side of Rutland, if not in the state.” Its architect was Elbridge Boyden, born in Windham County and practicing in Worcester, Massachusetts, where he designed the noted Mechanics Hall (1857). For this church he employed Victorian Gothic forms to create a dark brick building with Portland stone trim set on a rock-faced granite foundation. The simple rectangular church is elaborated on its facade with an engaged four-story central tower that has a polychrome octagonal steeple and is flanked by broken raking eave lines that articulate the nave and aisles. Tower, facade bays, and side walls have deep-set lancet windows in stone surrounds and corbel tables. Boyden topped the stepped buttresses on the facade with pinnacles.
Twenty years after its completion, the prospering Baptist Church was expanded by Boston architect Wentworth, who had just entered into partnership with Ralph Adams Cram. Wentworth enlarged the facade, making it more massive by removing the pinnacles and adding twin truncated corner towers with wall dormers and weighty hipped roofs. Pointed-arched doorways in the towers served as the new entrances to the church, and patterns of stepped lancets on their flanks announced staircases within. Along the north facade, Wentworth added a Tudor-arched gallery that tied the northeast tower to a new three-story rear addition with chapel and meeting rooms. In place of the original central door, the organ-manufacturing Estey family donated a large stained glass Tiffany window. Estey partner and former governor Levi Fuller donated another Tiffany window in 1896. This was followed in 1906 by the donation of an Estey pipe organ. As a result, this remained one of the most elegantly up-to-date churches in Vermont.