St John the Baptist, Hillingdon
St John the Baptist, Hillingdon is a medieval parish church which was restored and enlarged by George Gilbert Scott in 1847-8.. In 1846, his report recommended pulling down the existing chancel and extending the church eastwards, as well as adding north and south transepts. This work was carried out by Messrs James Fassnidge of Uxbridge in 1847-9 and the present east end, including the chancel with flanking chapels, was built.
As the capital of Empire put its tentacles through Middlesex, its small, humble flint-built parish churches were no longer fit for purpose. Many of them were quite brutally enlarged, with a mega-church clamped on the side. Hillingdon's church got off quite easy, and still could pass as a rural parish. Still, the exterior is quite seriously gone-over, with all the tracery remade in Bath stone.
Essentially all that is medieval left in-situ are the three-bay nave arcades, probably late fourteenth century, the north with much simple sculpture of heads. The north aisle roof, with jolly corbel busts, is fifteenth-century. Scott added a crossing of sorts, by springing an arch into a new pair of shallow transepts upon corbels, not columns, carved with the emblems of the Four Evangelists.
Scott reset the chancel arch preserving the exceptional thirteenth-century grimacing corbel enveloped by serpents on the north. It is of such high quality it could have come from the masons' yard of Westminster Abbey. Scott's sculptor had a bit of fun replicating it on the south.
His chancel is Decorated, the most neutral style at the time. The east window is a stock curvilinear design, an organ chamber to the south, two bay arcade to the north, and blind niches either side of the sanctuary for housing some superb seventeenth- and eighteenth-century monuments. Whereas some architects might be keen to put their own stamp on the extensions, Scott's is in keeping with the old: calm and respectful.
http://www.stjohnshillingdon.org.uk/resources/churchhistory