The comprehensive renovation of the 19th-century warehouse where the artist Donald Judd lived and worked encompassed a complete rebuilding of both exterior and interior. It was here that Judd first developed his conception of spaces in which art was permanently installed, in contrast to the temporary, generic conditions of a museum or gallery. After extensive research and within tight physical constraints, ARO installed extensive environmental and life safety systems with minimal visual impact, thereby preserving Judd`s original intent. Restoring the exterior involved the removal, cleaning, patching or recasting, priming, and repainting of over 1,300 cast-iron pieces.Architecture Research Office is the architect for the restoration of 101 Spring Street, the nineteenth century cast-iron warehouse in which the artist Donald Judd lived and worked from 1974 until his death in 1994. The building is notable for both its elegant, extensively glazed exterior and for the significant transformations that Judd implemented to the interior. The project includes the repair and preservation of the historic exterior fabric, together with extensive life safety, fire suppression and climate control improvements to enable the building to function as a museum and offices of the Judd Foundation.Donald Judd wrote of the building thus: “In November ‘68 I bought a cast-iron building in the Cast-Iron District of New York City. The building was built in 1870 and designed by Nicholas Whyte, whose only other cast-iron building is in Brazil… The given circumstances were very simple: the floors must be open, the right angle of windows on each floor must not be interrupted, and any changes must be compatible. My requirements were that the building be useful for living and working and more importantly, more definitely, be a space in which to install work of mine and of others….The renovation of the building and the permanent purpose of the building are precedents for the larger spaces in my place in Texas, Chinati de Mansana, for the Chinati Foundation, and will be for Ayala de Chinati.” Unlike most museums, 101 Spring Street affords the visitor the opportunity to understand Donald Judd`s creative process, as it was his home and source of inspiration. The building was a testing ground for Judd`s philosophical and artistic explorations. Therefore, the entire building is latent with the potential for teaching about his art. The goal of our efforts is to implement required building improvements with minimal visual impact so that the delicate relationships between the building, context and content are maintained.