In the heart of Cambridge, Massachusetts, a hop, skip and jump away from Harvard University, presiding over the restored Joan Lorentz Park, the Cambridge Public Library now stands with a new image of modern grace. Attached to the existing library designed in 1887 by Van Brunt & Howe, the new work of metal and glass offers us a model for sustainable, public projects. Designed by William Rawn Associates, the building is not only a case study of integrating sustainability into a house of knowledge, but moreover, the product of diligent research by a team that is interested in sharing that knowledge and progress with the profession at large.