Environmental controls should aim to maintain an environment that is not hospitable for pests. Environmental factors that can be controlled include; cleanliness, temperature, relative humidity and lighting. Ideally, your institution should strive to maintain environmental conditions that both discourage pests from being drawn into collections areas and from flourishing if they do enter.
The IPM-WG has created two template documents that can be used to create procedure documents specificly geared to your institution. One focuses on the control of climate and water sources, and the other on housekeeping procedures.