Octagons existed in the early Christian centuries, but usually in ancilliary buildings such as chapter houses, rather than places of worship. Anglican examples include three Shropshire churches designed by Thomas Telford between 1792 and 1805.
Wesley's preference for them, inspired by seeing Dr. John Taylor's new meeting-house in Norwich in 1757, was based on 'purely utilitarian and aesthetic grounds', including audibility. Fifteen Methodist octagons are known to have been built, beginning with Rotherham in 1761, which Wesley commended as a model design. Four have survived. Yarm (1764) with round-headed windows; in 1815 the walls were raised and a gallery added, and a porch in 1873, described by Dolbey as 'extremely ugly and wholly inappropriate'. Heptonstall (1764) was enlarged in 1802 to form an elongated octagon, with the gallery extended round all eight sides. (Similarly, the chapel built in Stroud in 1763 was in the shape of an 'elongated octagon'; it became a Salvation Army citadel about 1880.) Arbroath (1772) had a 'high gothic' porch added in 1882, and the original square-headed Georgian windows were replaced by pointed ones. Taunton (1776), now in secular use, has two tiers of windows, the upper circular and the lower arched, a gallery round five of the sides and one side later extended, perhaps to accommodate a choir.
Those no longer in existence were at Rotherham' (1761), Whitby (1762), Snowsfields, Southwark (1764), Aberdeen (1764), Edinburgh (1765), Chester (1765), Nottingham (1764), Thirsk (1766), Bradford (1766) and Gwennap (or Carharrack) (1770). The first Canterbury chapel (1764), known as the 'Pepper-box', was unusual in being twelve-sided.
Octagonal chapels occasionally occur in recent times; e.g. Ridgeway Church at Plympton (1993) near Plymouth.
'I was shown Dr. Taylor's new meeting-house, perhaps the most elegant one in Europe. It is eight-square, built of the finest brick, with sixteen sash windows below, as many above, and eight skylights in the dome, which, indeed, are purely ornamental. The inside is finished in the highest taste... How can it be thought that the old coarse gospel should find admission here?'
John Wesley, Journal, 23 November 1757
[At Bradford] 'They have just built a preaching-house, fifty-four feet square, the largest octagon we have in England; and it is the first of the kind where the roof is built with common sense, rising only a third of its breadth; yet it is as firm as any in England; nor does it at all hurt the walls. Why then does any roof rise higher? Only through want of skill, or want of honesty, in the builder.'
John Wesley's Journal, July 1766