“Perch & Dwell” is an ecological and social intervention at the Crystal Pavilion in Madrid, designed to foster interspecies coexistence between birds and humans while addressing Spain’s housing crisis through integrated social housing. Situated within the lush surroundings of Casa de Campo, the project transforms the pavilion into a shared sanctuary, blending elevated perches, nesting alcoves, and water features to attract local and migratory birds while providing affordable living spaces for people in need. Inspired by Madrid’s avian biodiversity, from storks along the Manzanares River to swallows weaving through urban corridors, the design blurs the boundary between architecture and habitat. By reimagining the pavilion as a living ecosystem and a model for sustainable urban living, Perch & Haven highlights the delicate balance between the built environment and urban wildlife, fostering coexistence, accessibility, and a renewed connection to nature.