The Phase 1 Refurbishment area in B539 was designed as an animal facility. At the time of the award of the Refurbishment construction effort, LASP noted that the area would support two animal programs with differing clean statuses. Changes were made during the Refurbishment to separate the two facilities. LASP then requested an airlock at the emergency egress door located near R149, as the Program has concerns that outside air could infiltrate the animal facility and contaminate their work. To reduce schedule impact on the Ph 1 Refurbishment completion, it was decided that the airlock would be constructed by another contractor after the Refurbishment area was turned over.