This design guide offers guidance to science educators, architects, and others concerned with the provision of science accommodations in Ontario, Canada, either through new construction or the adaptation of existing buildings. The publication is not a blueprint for facilities nor an attempt to standardize all science programs and facilities; it is intended to be used as a starting point to support sound decision making in the creation of facilities which are effective learning environments for science programs. The guide is chiefly concerned with provision of science teaching accommodations for students in grades 7 to 12, but much of the general guidance is equally applicable to younger students in elementary school. The guide's sections address: (1) general design considerations; (2) services (such as gas and electricity); (3) ventilation and the thermal environment; (4) lighting and acoustics; (5) safety; (6) equipment, furnishings, and finishes; (7) allowance for computer technology; (8) laboratory design; (9) the preparation room; and (10) chemical storage provision. Appendices contain the Ontario building code, a summary of services required for a school laboratory, the Science Teachers' Association of Ontario (STAO) position statement regarding class size, and a listing of activities in the preparation room and their requirements. (Contains 25 references.) (EV)