Nothing is known of any architectural training, although Howard Colvin suggests that his knowledge of up-to-date styles points to time spent with an architect of standing.

His papers show him to have made tours of Germany and Italy, as well as parts of England, notably Oxford, Cambridge and Fonthill.

An extensive archive of Newall's sketchbooks, drawings and plans have survived and were purchased by Dumfries Museum in the spring of 1991.

Newall remodelled a windmill in neoclassical style to serve as the town observatory, which later became Dumfries Museum.

His Greek Revival-style villas were admired by J. C. Loudon, and Hannahfield (later called Ladyfield West), on the Nith south of Dumfries (the only Category A-listed building by Newall, but which has sadly not 'enjoyed' statutory protection) featured in his Encyclopaedia of Cottage, Farm, Villa Architecture (1834).