W1555 is a housing cooperative located at Wolphaertstraat 15-55 in Rotterdam, Netherlands. The project involves the circular transformation of a pre-war building into a 46-unit housing cooperative with additional communal spaces. The building has an interesting history, having been squatted in 2004 by a group of young artists who formed the NAC Foundation.

In 2015, discussions began about sustainably transforming the housing block. A new residents' association, W1555, was established to work on this project. Through collaboration between Superuse Studios, the residents, and Woonstad Rotterdam (the property owner), a design and renovation plan was created.

The renovation includes changing the typology from pre-war flats to gallery flats, addressing issues such as poor balcony conditions and improving daylight in the homes. The project emphasizes sustainability by preserving the existing building and adding mostly circular and bio-based materials.

W1555 aims to create a sustainable and affordable living space for creators, with a focus on supporting each other in daily life and contributing positively to the neighborhood. The cooperative values affordable living, diversity, tolerance, ecological awareness, and access to education and culture. After the renovation, the association will manage the complex, renting apartments to its members and operating the communal facilities.