Various workers have, in the past, proposed constant levels of temperature, humidity, light and pollution which would constitute such an ideal environment for many types of materials. These levels are examined, the practical problems of creating and maintaining some of them are discussed and an attempt is made to evaluate the feasibility of a constant environment in the light of Canadian construction and climatic restrictions. From this study, control based on maximum and minimum acceptable levels appears feasible and these levels could form a basic set of environmental control guidelines for museums, galleries and archives in Canada.