The architect of the new church, the second on the site, was the rector Charles Conybeare’s younger brother Henry Conybeare, a civil engineer with an interest in Gothic architecture, who had designed the Afghan Church in Colaba, Mumbai, where he had also been responsible for improving the city’s sanitation. Sir Nikolaus Pevsner described St Mary as “serious and impressive” and “quite a remarkable church for its date”.
The church is of brown and grey rubble stone with limestone dressings. Above the west entrance door is a rose window, given by Lady Ashburton in memory of her husband. At the east end is a polygonal apse, whose gables have two-light bar tracery windows. There are four sets of three tall lancet windows in the side walls of the church. The steep roof is of purple and grey-green slates in a diamond-shaped pattern. There is a belfry with two bells between the nave and the chancel.
The chancel/apse is semi-octagonal with moulded ribs and wall columns. It has a vaulted stone roof. The five long arched windows of two lights with small rose windows contain little pieces of clear, red, blue and green glass arranged in geometrical patterns. The circular floor is covered with glazed brown and green tiles laid out in the form of a labyrinth, as in Chartres Cathedral.