The Plumb Windows are two stained glass windows that were installed in a private residence in 1974.

Speaking on the project in interview with Hans Ulrich Obrist, published in 2023 in Brian Clarke: Collages, Clarke said:

'...It’s about what happens when you look across a field and you see dots that interrupt the field of colour, and those dots are flowers. Flowers have always played an important role, and a non-specific significance in the development of my work.'