Robert Abraham's design represents a "brief appearance" of the Romanesque Revival style in the architectural history of Nonconformist chapels in Sussex.
 There are also elements of Neo-Norman architecture.
 Ian Nairn dismissed the building as "not good", and notes its similarity to the "gloomy" town hall and council offices of 1836 by Abrahams.

The façade is of knapped flint with galletting and stone quoins, dressings, buttresses and string-courses.
 The side walls have red and grey brickwork and knapped flint.
 The front elevation is divided into three equal-width bays by full-height ashlar-faced stone buttresses in the form of pilasters, which terminate at a stone string-course separating the gabled slate roof (enclosing attic space) from the body of the two-storey building.
 The eaves are supported on ashlar corbels.
 Below the gable, at the attic level, is a louvred round-arched window surrounded by roll-moulding.
 The first floor has three tall windows with round heads, and the centrally placed entrance at ground-floor level is set into a similar arch flanked by capital-topped colonnettes (small medieval-style shafts).
 The stone used for the window and door surrounds, string-courses and buttresses was quarried at nearby Pulborough.
 Inside, the original gallery on the north wall (surrounding the entrance) survives, but those on the west and east sides have been removed.

There was originally a garden at the front.
 Its surrounding walls and gate piers are included in the English Heritage listing.
 They are of brick with inlaid flints and stone dressings and coping.
 The piers are also of stone from Pulborough, and have string-courses and decorative panelling.
Robert Abraham's design represents a "brief appearance" of the Romanesque Revival style in the architectural history of Nonconformist chapels in Sussex.  There are also elements of Neo-Norman architecture.  Ian Nairn dismissed the building as "not good", and notes its similarity to the "gloomy" town hall and council offices of 1836 by Abrahams.
The façade is of knapped flint with galletting and stone quoins, dressings, buttresses and string-courses.  The side walls have red and grey brickwork and knapped flint.  The front elevation is divided into three equal-width bays by full-height ashlar-faced stone buttresses in the form of pilasters, which terminate at a stone string-course separating the gabled slate roof (enclosing attic space) from the body of the two-storey building.  The eaves are supported on ashlar corbels.  Below the gable, at the attic level, is a louvred round-arched window surrounded by roll-moulding.  The first floor has three tall windows with round heads, and the centrally placed entrance at ground-floor level is set into a similar arch flanked by capital-topped colonnettes (small medieval-style shafts).  The stone used for the window and door surrounds, string-courses and buttresses was quarried at nearby Pulborough.  Inside, the original gallery on the north wall (surrounding the entrance) survives, but those on the west and east sides have been removed.
There was originally a garden at the front.  Its surrounding walls and gate piers are included in the English Heritage listing.  They are of brick with inlaid flints and stone dressings and coping.  The piers are also of stone from Pulborough, and have string-courses and decorative panelling.
Trinity Congregational Church, Arundel