Like the neighbouring Bellingham Estate,
Downham was one of the cottage estates developed by the London County Council in the inter-war years. Built between 1924 and 1930 to plans by the LCC architect George Topham Forrest, it provided 7,000 new homes. The site for the Catholic church and school
was acquired for £1450 at the heart of the estate, adjoining the large park called Downham Fields.
Mass was said from April 1927 at the Studio Club, by Canon William H. Monk, then financial secretary and resident at the Convent, Belmont Hill,
Lewisham. The first resident priest was Fr Joseph Simmons (from December 1928). As at Bellingham, initial efforts were directed towards the building of a primary school, while a temporary church was erected. The first church on the site was a hall, erected
at a cost of £1800 and used for the first time on 20 October 1929. The primary school opened on 26 August 1930, and the presbytery was in use by about 1932. Two extra chapels were added to the church in 1934 and 1935.
Building work for the present
church started in February 1961 and the foundation stone was laid on 16 September 1961 by Bishop (later Archbishop) Cowderoy. It was largely complete by 1962 and was opened on 27 October 1963. The architect was Donald Plaskett Marshall & Partners and the
builder was T. J. Nally of Connaught Construction Ltd. The cost was £40,000. Photos of a model of the church in 1961 show a 90ft-high tower beside the west front; the current brick stump
at the southwest corner might be the remnant of the tower.
The sanctuary was reordered in the 1970s when the original altar was moved further west and a stained glass window was installed at the east end. The window had been brought to Downham
from the Convent of St Philomena at St Mary Cray, Kent. The church was dedicated on 25 November 1984 by Archbishop Bowen.
The church is facing south; however, this description will follow the conventional liturgical orientation.
The church is
a modern and functional building, built with a reinforced concrete portal frame. In plan, it consists of a single volume nave and sanctuary, with a sacristy extension to the southeast.
Originally, it appears to have had a tower to the south of the west front, which was either not fully built or radically shortened. The pitched roof has a short pinnacle above the sanctuary area.
Internally, there is a narrow one-bay lobby and a nave
of six bays, followed by a sanctuary of two bays. Every second bay there is a gabled clerestorey window. There is an organ loft at the west end. Furnishings include the black marble sanctuary furniture of altar, tabernacle stand, lectern and font, as well
as the east window. Originally, the east wall was part glazed, part panelled in wood until the current window was installed in the 1970s. The window was designed and constructed by Hugh Powell in 1965 for the Convent of St Philomena at St Mary Cray, from where
it was moved to Downham. It is made from hand-made antique glass and epoxy resin with slate powder in a technique called ‘Resglaze’, invented by Powell.