An ugly brutalist architecture social building is probably the last thing you’d expect amid the posh and elegant Neue Altstadt Quarter in Frankfurt. And yet, the smallest house here is indeed a reference to the government-subsidised suburban block buildings all around Germany – and it’s a birds nesting house!

Artist Guido Zimmermann first started creating Cuckoo Blocks, cuckoo clocks shaped like suburban block buildings, as an art project. His idea: “The classic cuckoo clock stands for the prosperity of the middle class and counts as a kind of luxury good for the decent home. The updated version as a prefabricated building shows today’s urban and social life in apartment blocks.”

Now he has moved the idea to creating birdhouses with the same approach. His “Sozialmeisenbau”, social tit-house, is quite well hidden in a tree on Braubachstrasse. Try to spot it! I’ve not noticed if by chance some tits or other birds have moved in, looks like there is some space available in this premium location of Neue Altstadt!