The 640 birdhouses project is one of the biggest projects of Happy City Birds.

In 2012 Thomas Dambo made a workshop where him, a couple of volunteers and a huge bunch of festival guests created and decorated 640 birdhouses from recycle / scrapwood. The houses were then hung up in trees around the main stage (Orange stage) of the music festival.

After the festival the houses were handed out to people on the central train station of Copenhagen, and the recievers were asked to upload there picture to the Happy City Birds Facebook page.