Alexander Nisbet Paterson was born at Berkeley Terrace, Glasgow on 3 May 1862, the youngest son of Andrew Paterson and his wife Margaret Hunter.

His father, Andrew, was a good watercolourist as well as an astute businessman and most of his family developed artistic interests. James, born 1854, became the Glasgow Boys painter and William, born 1859, was later to own a Bond Street art gallery in London.

Alexander was educated at the Western Academy and at Glasgow Academy. His parents wanted him to enter the church and he attended Glasgow University where he graduated MA in 1882. He really wanted to become a painter like his eldest brother but his parents could not afford two painters in the family. Architecture was decided on as a compromise. Alexander entered the Ecole des Beaux-Arts and the atelier of Jean Louis Pascal in 1883.

In 1886 Paterson returned to Britain to work with James Burnet. There he worked first as an improver and as a draughtsman, his skill as a watercolourist being much in demand for the presentation perspectives of the firm’s projects.

In 1889 he won the RIBA silver medal and passed the qualifying exam. He was admitted ARIBA on 3 March 1890. He moved to practice of Sir Aston Webb & E Ingress Bell as Webb’s assistant on the competition for the South Kensington Museum before commencing independent practice in Glasgow late in 1891.

In 1896 having won the Godwin scholarship Paterson took a career break to visit the USA to study domestic architecture. On his return he married Margaret (Maggie) Hamilton, sister of the Glasgow School painter James Whitelaw Hamilton in 1897 and a talented artist in her own right, his father giving him Turret, one of the four houses in Helensburgh he had financed to help start Paterson’s practice; his father and mother themselves moved to Torwood House, Rhu in 1893 as all the family were keen on sailing.

In 1900, Patterson began planning his private Long Croft home in Helensburgh at Rossdhu Drive. The Long Croft was not simply built as a family home, but as a setting for the artistic creations of himself, his wife and their circle of artistic friends. Within the house, Patterson created a studio, primarily to cope with the burgeoning number of Helensburgh clients. The house was later described by his daughter, Mary Viola, as ‘embodying much of the last 100 years of Scottish Art’.

In early 1903 Campbell Douglas merged his practice with Paterson’s as Campbell Douglas & Paterson. After a recurrence of an old illness, Douglas retired and Paterson thereafter practised alone but retained Douglas’s name in the firm title until at least 1910.

Paterson was admitted FRIBA on 28 February, and was elected ARSA in 1911. He became a Governor of Glasgow School of Art in 1916.

Paterson was affected by cancer of the throat in c.1936. The operation to remove it was successful but he had to relearn how to speak and he handed his practice over to John Watson Junior of Watson & Salmond. Paterson then devoted the rest of his life to watercolour painting, having been RSW since 1916.

Amongst the many Helensburgh buildings that Paterson is associated with is the East Clyde Street School, which was constructed in 1902.

His other interests were golf, hill-walking and the Ancient Monuments Board of which he became a member in 1930.

Paterson died at Helensburgh on 10 July 1947. He was survived by Maggie who died on 21 January 1952, his artist daughter Mary Viola and a son Alastair Hamilton Paterson who entered the army and rose to the rank of Major General.