A smart new renovation and addition to this historic library make civic space remarkable. The design emphasizes the contrast between the old and new, bracketing time in a wonderful way. The 1889 rooms are all about the interiors, while the addition celebrates the exterior and its connection to the park. There’s tremendous uniformity in the structure of the new building, with the simplest things done very well. It’s technically interesting, incorporating a louvered double curtain wall (the first of its type in the United States) that bathes the library in light while adding texture and allowing a nesting of visual scale. The technology is complex and beautiful, and it appears to work, though we’d like to read a postoccupancy report to gauge performance. We love the old part, too. It’s clear that the architects and client took equal pride in the both aspects of the library. We found it heavenly and wanted a chance to go in.

 The main building of the Cambridge Public Library is an historic library building at 449 Broadway. Built in 1888, its land and full construction funding were provided by Frederick H. Rindge, a Cambridge native and philanthropist. It was added to the National Historic Register in 1982. A $90 million expansion and renovation of the library, led by the Boston architectural firms William Rawn Associates and Ann Beha Architects, opened on November 8, 2009. The new addition more than triples the square footage of the building, and is the first building in the USA to make use of European Double-Skin Curtainwall technology. During most of the construction, the library collection had been relocated to the Longfellow School. 