Blacket's former pupil William Wakeling arrived in Ipswich in 1856 and worked there for several years including some time as the partner of Thomas Casey as builder/architects; he carried out supervision of St Paul's and was also responsible for "the internal arrangements".

In 1929, Ipswich architect and prominent parishioner George Brockwell Gill designed and supervised an extension to the chancel, and the addition of an organ chamber, sacristy, chapel and vestry to the west end and southern transept.

[1] The church contains fine stained glass windows and numerous memorials including marble tablets honouring people notable in Queensland history such as George Thorn and Thomas de Lacy Moffat.

[3] A church hall was built in 1908 but was demolished in 1962 along with the timber belltower and replaced by a new brick and steel parish centre which was dedicated as a war memorial; it was designed by Conrad and Gargett Architects.

The steeply-pitched gable roof is sheeted with flat pan-and-roll galvanised iron and is penetrated by dormer window ventilators.

The church interior contains some fine timber joinery including sanctuary screens, communion rail and panelling of cedar and pine.

A chapel in the north-eastern corner of the nave honours Mavis Parkinson and contains an altar faced with New Guinea tapa cloth and a small bamboo cross in a glass case.

[1] The rectory is a lowset timber building with verandahs on all sides and a fine projecting pedimented entrance porch to the east overlooking the town centre and d'Arcy Doyle Place.

[1] The interior plan form of the rectory remains relatively unchanged except for minor modifications to accommodate the church offices, meeting rooms and storage space.

Contemporary car accommodation has been constructed at the rear and a disabled persons ramp built alongside the northern verandah.

[1] The church grounds are raised above the surrounding footpaths and contained on all sides by early limestone retaining walls with sloping concrete copings, once surmounted by a small picket fence.

A pair of circular crenellated gate pillars exist at the main northeast entrance and are constructed of random rubble limestone matching the walls adjacent.

The place demonstrates the pattern of Queensland's history, exemplifying the buoyant mood of pre-Separation Ipswich and the aspirations of its citizens to construct community buildings worthy of its perceived importance.

With its central city setting and landscaped grounds including a fine limestone wall and terraces, it is a major landmark in Ipswich.

[1] It is associated with the life and work of Anglican Church martyr Mavis Parkinson, a medical missionary who was killed in New Guinea during World War II.