The church is rectangular in plan with a flat ceiling and a small apse serving as a chancel. The east front, towards the street, has a portico in the Tuscan order, with a central arch cutting through the entablature and pediment—a motif used in Wren's "Great Model" for St Paul's Cathedral. A giant order of pilasters runs around the rest of the church, a feature Kerry Downes suggests may have been added by Thomas Archer, who, according to the minutes of the Commission, "improved" Hawksmoor's plans. On the north and south sides of the churchwide projecting vestibules rise to the full height of the building, with steps leading up to the doors.