He was educated at St Paul's School, and after a short course of instruction in his father's office was in 1801 admitted a student of the Royal Academy, where in the same year he gained the silver medal for his drawing of the tower and steeple of St Dunstan-in-the-East. In 1811 he published a Treatise on the Equilibrium of Arches, and in 1815 he was elected FSA.
After a visit to Italy in 1816, he published in 1818 Notitia architectonica italiana, or Concise Notices of the Buildings and Architects of Italy. In 1825 he published an edition of Sir William Chambers's Treatise on Civil Architecture; and among his other principal contributions to the literature of his profession are a translation of the Architecture of Vitruvius (1826), a Treatise on the Rudiments of Architecture, Practical and Theoretical (1826), and his valuable Encyclopaedia of Architecture (1842), which was published with additions by Wyatt Papworth in 1867.
In recognition of Gwilt's advocacy of the importance to architects of a knowledge of mathematics, he was in 1833 elected a member of the Royal Astronomical Society. He took a special interest in philology and music, and was the author of Rudiments of the Anglo-Saxon Tongue (1829), and of the article "Music" in the Encyclopaedia metropolitana.
His principal works as a practical architect were Markree Castle near Sligo in Ireland, and St Thomas's Church (1849–1850) at Charlton in Kent (today part of the Royal Borough of Greenwich) and the tower of St Thomas, Clapton Common (1829).
Gwilt was also associated (c. 1813–1830) with a flawed and short-lived attempt to rebuild the mediaeval predecessor of today's St Margaret's Church in Lee. When it became clear that the foundations of the old church were incapable of supporting a new building, a new church was commissioned, from another architect, on land nearby.
A portrait of him is part of the permanent collection at the National Portrait Gallery in London.
|Wikisource has the text of the 1885–1900 Dictionary of National Biography's article about Gwilt, Joseph.|
- Southwark diocese entry for church of St Thomas Archived 2004-11-06 at the Wayback Machine
- London 4 : North. Cherry, Bridget., Pevsner, Nikolaus, 1902-1983. New Haven: Yale University Press. 2002. p. 484. ISBN 0-300-09653-4. OCLC 719418475.CS1 maint: others (link)
- History of the Parish Church of St Margaret of Antioch, section 6: History "Archived copy". Archived from the original on 2011-12-05. Retrieved 2011-11-08.CS1 maint: archived copy as title (link)