This building can be found in the middle of West Middlesex golf course in Dormers Wells, Southall. I think it looks like a old water company building but I can’t find a reference to it. Edited to add: I did find a reference on a map from the 30s to confirm that this was a valve house so it is related to waterworks. The golf course is in the Brent river valley.
Sir Basil Spence was a prolific architect of the Modernist and Brutalist styles. What ever you think of the buildings he designed, there is no little amount of irony in comparing what he built versus the house he actually lived.
We were following a walk along the course of the New River in Highbury/Stoke Newington which was pretty dull along the culverted stretch along Petherton Road but this lovely representation of a zebra crossing with vigorously flashing Belisha beacons painted on the pavement of Church Path (overlooked by a black cat lounging on a window sill) was a nice surprise.