The objectives in designing safety laboratories may be set out in the one sentence "to provide a workplace which is suitable for the intended purpose(s), to allow for human factors, and to include necessary intrinsic safety features, so far as is reasonably practicable". Far-sighted and skillful management of this interactive system is essential to ensure a successful design outcome. In this chapter, the author tries to contrast two laboratory buildings in which he have worked. The ventilation system is the first safety feature, since the large separation of over 50 ft between fume outlets and air inlet prevented fume recirculation with very few exceptions. The second safety feature was that each pair of laboratories had service room between them, and one of these on each floor was specially fitted for running of unattended experiments in fume hoods overnight. The third intrinsic safety feature was that each laboratory had a standard "safety unit" set into the wall just inside the doorway.