Howard Colvin's assessment of him was that of "a competent architect, but he lacked inventive fancy, and his buildings are for the most part plain and unadventurous in design".
[1] The son of a Hampshire parson also named John James, he attended the Holy Ghost School, Basingstoke, of which his father was headmaster.
He was the professional on site for the construction of East India House, Leadenhall Street, London, to designs by the merchant and amateur architect Theodore Jacobsen, 1726–29.
Also in south-east London, James designed Wricklemarsh, "a pioneer Palladian mansion" (Colvin) and in fact his only Palladian-style structure, for Sir Gregory Page in 1723.
Thus John James can be seen as one of the intermediaries who made Baroque Continental practice in architecture, decorative painting and formal garden planning available to English patrons and craftsmen.