Spiller was a pupil of the architect James Wyatt and became a close friend of John Soane, who sometimes employed him as a surveyor, and to draft papers on subjects on which they shared views such as the evils of speculative building.
[2] John Summerson described Spiller as "a clever man, with a difficult temperament, which perhaps was against his emerging into the front rank of architects.
[3] In 1812–13 he added porches and, in stark contrast to the rest of the structure, a Portland Stone steeple with flowing curvelinear elements.
[4] In 1817 he remodelled the interior of James Wyatt's chapel of ease (later the Church of Saint John the Baptist) in Highgate Road, Kentish Town,[5] and in 1820 he added a portico with square piers to Benjamin Dean Wyatt's Theatre Royal, Drury Lane.
[2] He died in at his home in Guildford Street, London on 3 May 1829 [7] His brother John (1763–94) was a sculptor who made a statue of Charles II for the Royal Exchange.