[3] Holy Trinity's organ was still being built by Messrs William Hill & Sons at the time of the church's opening, resulting in the temporary use of an American harmonium.

[4] In 1899–1900, the south transept was converted into a side chapel, with the work carried out by Messrs Norman and Burt of Burgess Hill to the designs of Charles Eamer Kempe and paid for by Miss Ashley of Stratton Manor.

[8] After World War I, a tablet of Portland stone was added to the exterior of the church to commemorate the men of the parish who lost their lives in the conflict.

[1] Holy Trinity was declared redundant on 1 May 1975 and then sold to the Roman Catholic Diocese of Plymouth,[9] who at the time were in need of greater accommodation than their existing Dorchester church, Our Lady Queen of Martyrs and St Michael, could afford.

The sale of the church was completed in May 1976 and restoration plans drawn up by Anthony Jaggard of John Stark & Partners in Dorchester.

[1] A number of fittings were installed from the original Roman Catholic church, including an onyx marble altar and the Stations of the Cross.

Owing to the difficult site and limited space from surrounding development, the chancel's size had to be restricted and the nave's south aisle shorter than its northern counterpart.

The woodwork fittings were created under the personal supervision of Mr. Tilley, while carvings in wood and stone was executed by Mr. Frank Witcombe of Bristol.

[3] The original octagonal font of Caen stone was carved and gifted by Mr. Grassby of Dorchester as a memorial to four of his children who died in their infancy in 1870.

[3] A number of fittings and features from the previous church were also installed inside the new building, including a bell of 1732, made by the Bilbie family, an oak chest of 1683 in the nave and various monuments, largely dating to the first half of the 19th century.