Building 20

Building 20 (18 Vassar Street, Cambridge, Massachusetts) was a temporary wooden structure hastily erected during World War II on the central campus of the Massachusetts Institute of Technology. Since it was always regarded as "temporary", it never received a formal name throughout its 55-year existence. The three-floor structure housed the Radiation Laboratory (or "Rad Lab"), where fundamental advances in physical electronics, electromagnetic properties of matter, microwave physics, and microwave communication principles were made, and which has been called one of "two prominent shrines of the triumph of science during the war". A former Rad Lab member said, "At one time, more than 20 percent of the physicists in the United States (including nine Nobel Prize winners) had worked in that building".

After the Rad Lab shut down after the end of World War II, Building 20 served as a "magical incubator" for many small MIT programs, research, and student activities for a half-century before it was demolished in 1998.

The building was hurriedly constructed in 1943 as part of the emergency war research effort, however it continued to be used until shortly before its demolition in 1998, making it one of the longest-surviving World War II temporary structures on campus. The building had the overall shape of an extended mirror-reversed "F", with multiple parallel "wings" connected to a longer spine which paralleled Vassar Street. The spine of the "F" was slightly skewed compared to the projecting wings, because of the gradual divergence of Vassar Street compared to Memorial Drive, which runs parallel to the Charles River Basin.

The three-floor structure was framed with large wooden posts and beams, supporting massive floor planks which creaked and groaned underfoot. The structure was extremely sturdy, but it complained continually under its burden of heavy equipment and material. The ground level floor was concrete slab. Over time, the interior walls became a hodgepodge of Transite, Masonite, and gypsum wallboard as various occupants grew, shrank, or repurposed their spaces.

The roof was flat, covered in tar paper and gravel, and emitted radiant heat into the top floor whenever the sun shone. The outer sheathing consisted of asbestos-cement shingles painted a dirty white in a vain attempt to reduce solar heat load. The windows were leaky, rattling wooden sash, and bristled with numerous large window-mounted air conditioners, since the interior spaces would otherwise become unbearably hot during warm weather.

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Wikipedia