The architect of the present church was John T Mair (1876-1959), an Invercargill-born architect who later became the Government Architect.
J T Mair, who had previously worked in the New Zealand Railways, had travelled to the United States of America in 1906, where he studied architecture at the University of Pennsylvania. It is thought that the Romanesque and Byzantine-influenced church he designed for the Presbyterian congregation in Invercargill was influenced both by buildings he saw in America and churches he saw on his travels through Italy and France on his way back to New Zealand.
Internally Mair's design conformed to the Presbyterian way of worship by providing a central space and a gallery so that all could see and hear the preacher. It is said that Mair made a special study of acoustics and in that respect First Church was 'nearly as perfect as possible'. At the rear of the church Mair provided rooms for prayer meetings and for Sunday School.
Mair's design was accepted by the Deacon's Court in 1910, although not all approved of the design. The design, which included a dome, had to be modified to reduce costs. The tender was not let until December 1911, and then only on the proviso that the Deacons' Court could revert to the original design if they found further funds. The successful tenderers were McKinnon and Hamilton, and, as the Deacons' Court did find more money, the church was eventually built to Mair's original design.
Built in brick, First Church officially opened in 1915. At the time of its opening the Southland Times said: 'The building has been referred to by visiting architects from Dunedin and elsewhere, as one of the finest examples of brickwork in New Zealand. Being quite different from the customary style of Gothic architecture, the amateur mind has some difficulty in convincing himself that the design is just exactly to his or her liking, but as time goes on, and one becomes more familiar with the outlines of the structure, the objections will vanish
From the NZHPT website
On 24 February 1910 a congregational meeting resolved to accept the plans of Mr John T Mair for the building of the new Church. This was a courageous decision, as the Italian Romanesque architecture in which the building was designed was almost unknown in this country, and it naturally aroused some controversy. However, time has justified the decision and the Church has proved to have a nobility and enduring quality frequently absent from its Victorian Gothic and Edwardian contemporaries. A contract was let to Messrs McKinnon and Hamilton for the erection of both church and Stobo Hall at a cost of £15,193.
From "First Church of Southland: a descriptive guide" by Russell E Cowley, 1957