Opened in 1904, close to the port area of Wellington, the Former Missions to Seamen Building was designed to draw sailors from the temptations of the city. The Missions to Seamen movement was founded in Bristol, England in 1856 by Anglican clergymen who wished to promote the spiritual welfare of seamen. In 1898 James Moore, a lay preacher, was sent to New Zealand to establish a Wellington branch of the mission. Wellington was visited by thousands of ships each year in the late nineteenth century. When ashore, sailors sought out entertainment by visiting bars and taverns and the numbers arrested for disorderly behaviour were very high. To distract them from the taverns, Moore invited sailors to religious services and arranged entertainment at various locations around the city.

Despite the lack of a permanent building these activities proved popular with sailors and Moore received support from prominent New Zealanders, including the then Governor-General, Lord Ranfurly. In 1903 Mary Williams donated £7800 of the fortune her late husband Captain 'Bully' Williams [1832-1890] had made running his fleet of coal ships between New Zealand and Australia. Moore agreed to use the donation, then one of the largest ever made in New Zealand, to erect a building as a permanent memorial to Williams' husband and as a social and spiritual centre for sailors.

The Missions to Seamen building was erected on land reclaimed from the sea in 1876. The land was sold into private ownership in 1883 but remained undeveloped until the foundation stone of the Mission building was laid in 1903. The building was designed by the local architectural firm of Crichton & McKay and cost £5247. The rectangular building is an interpretation of the Edwardian Freestyle Movement but it incorporates an eclectic mix of other architectural styles. Based on the first Missions to Seamen building in Bristol, the building's upper floor was designed as a church while the lower floor included a large, lofty hall, a small office and lodging for the caretaker. Both the church and hall could accommodate up to 400 people, indicating the numbers expected to attract to the building. The building was officially opened by the then Governor General Lord Plunket in 1904.

The building's facilities were available to 'sailors of all nations, creeds and classes and constitutions'. The large hall had excellent acoustics and free entertainment such as concerts, dances and lectures were a standard occurrence. Regular services were held in the upstairs chapel. Also available was an extensive library and postal service. James Moore provided counselling services and encouraged sailors to sign a pledge against the consumption of alcohol. The Mission was very successful and, according to Moore, it played a substantial role in reduction of arrests of drunken sailors from 554 in 1902 to just 290 in 1909.

In 1912 Moore returned to England to recover from a period of ill health. When his application to continue his work in Wellington was declined, Moore disassociated himself from the Missions to Seamen movement. Despite protests from the Mission authorities in England, a new trust deed was drawn up and Moore ran the building as a private citizen. On Moore's death in 1932 the Missions to Seamen authorities regained control of the building and appointed a Mr Williams to Moore's position. During the Second World War the increased number of ships docking at the Wellington port meant the building was used extensively. To entertain the extra sailors, movies were shown in the hall and parcels of food and clothing were handed out. After the war, attendance slowly declined. By 1975 falling visitor numbers and the rising costs of maintenance prompted the relocation of the Mission to a small house in Kelburn.

The Missions to Seamen building was sold to the Government and used as a storehouse and community centre until 1985, when rising property values prompted plans to demolish the building and sell the land. The plans galvanised members of the public to launch one of the largest campaigns to save a heritage building in New Zealand's history. By 1986 the strength of the campaign forced the government to agree to preserve it. Despite the registration of interest in the building by a number of groups, it continued to be used for storage until 1994, when the interior was severely modified during its conversion into 10 private apartments.

The Former Missions to Seamen Building is historically significant as the first purpose-built Missions to Seamen building in New Zealand. The erection of the building indicates the scale of the need for an alcohol-free haven for sailors in the bustling port of Wellington at the turn of the nineteenth century. It has cultural significance for its years of effective and useful service to seamen, particularly during the Second World War. The building is also noteworthy for its links to two of Wellington's prominent citizens, Captain Williams and his wife.

The exterior of the building has architectural significance as an example of the work of the talented local firm Crichton & McKay. One of the last examples of their work, the building demonstrates the firm's ability to successfully combine diverse architectural styles to create a unique landmark. The building is also an important landmark in the development of public awareness of the importance of heritage. The successful public campaign to save the building in the 1980s, a reaction against the development focus prevalent in that period was one of the more important heritage campaigns ever undertaken in this country. The campaign demonstrated the power of public opinion and highlighted the esteem in which the building was held.