Paul Bellenoit knows libraries. In 19 years since joining Harvard University he has worked on hundreds of projects, including a five-year renovation of Widener Library and the redesign of Lamont’s three reading rooms and café. He also led the 27% reduction of the libraries’ greenhouse gas emissions and has been involved in the packing, shipping, re-shelving and relocating of 15 million books for renovations, library decommissioning and donations.

Though these projects differed greatly in scope and logistics, under Bellenoit’s watchful eye they had the same results: all on time and on budget. Bellenoit has kept meticulous records of the changes from project documents and photos to floor plans. These records are a collection in and of themselves — not as amazing as the ones Bellenoit has been charged with protecting, but a vital piece of the history of Harvard’s historic libraries.

In November, Bellenoit will leave Harvard and will run his own consulting business. We sat down with him for a retrospective.