These war-time housing developments of 1941-42 were built for war-workers to the Modernist designs of architect Geoffrey Jellicoe (1900–1996). They were built near munitions factories using local bricks. Vining notes that the ‘concrete flat roofs, floors and stairs [reflected] the scarcity of timber at the time, but also [provided] structural strength towards the incorporation of the required air raid protection.’ 

RCAHMW. July 2021.

Sources

Finn Jensen, ‘The secret wartime housing estates of Geoffrey Jellicoe’, Architectural Research Quarterly, Vol.12, Issue 3-4, December 2008, pp.313-23 
Jonathan Vining, 'Modernism in Wales', Masters Dissertation, University of Bath, 2013-14, p.40