The Greenhouse Zone occupies the top floor of the Stewart Biology building's South Block and shines brightly over the Montreal skyline. The venlo-style glasshouse was custom designed by Alex Turkewitsch (Greenhouse Engineering, Toronto, Ontario) and constructed by the firm of Frank Jonkman & sons (Bradford, Ontario).

The structure is divided into 10 independent research compartments each equipped with 175 ft² of space on rolling benches. All research zones are identically outfitted to assist design and replication of experimental work. Heating is supplied in two stages by under-bench and peripheral hot water lines. Cooling is provided by rooftop ridge vents, evaporative pad coolers, and overhead misting nozzles. Bench temperature can be maintained between 5°C and 35°C during the winter months and 4°C below ambient to 40°C during summer months.

All zones are equipped with automated thermal screens (50% light reduction), supplementary lighting (1000W HPS/ 8-12/compartment), high-pressure fog nozzles for RH% control (MEC Systems inc., Chilliwack, BC) and optional drip irrigation systems. A CO₂ analyzing station allows continuous monitoring and dosing of all research zones. A headerhouse is centrally located and equipped with soil mixing equipment, filtered fume hood, and supplies for users to mix and pot up soils, or harvest plants.

All greenhouse zones are independently controlled and monitored by Argus Titan control system (Argus Controls, Surrey, BC) which are linked to a central control computer in the Phytotron office. The Argus computers provide integrated control of temperature, relative humidity, lighting, CO_2, and irrigation in response to programmed variables as well as inputs from the compartment sensors and rooftop weather station.