Why Does Your Building's Garage Door Sound Like a Wind Tunnel in Winter? The Stack Effect, Explained

Many high-rise residents notice pressure-related symptoms such as doors that resist opening, air movement around garage doors, or changes in elevator-shaft airflow during very cold weather. These effects can be associated with the stack effect, the movement of air caused by temperature and pressure differences in tall buildings.

In City Site’s podcast “Ontario Fire Code Changes Condo Boards Need To Know in 2026” with Sam Soltani of The Trace Group, we discuss exactly how the stack effect affects garage doors and air movement in winter, alongside other building performance, maintenance, and resident comfort. The episode helps translate an everyday winter complaint into a building-science and maintenance question.

It gives boards a better starting point for discussing airflow, equipment condition, and whether a recurring problem needs more than a quick adjustment. Check out more information about this podcast here: #WeSpeakCondo podcast

What Stack Effect Actually Is

Warm air rises. In winter, a high-rise building is essentially a tall, leaky chimney: the heated interior air is lighter than the cold air outside, so it drifts upward through shafts, stairwells, and elevator wells, and escapes at the top. Cold air rushes in at the bottom to replace it. The taller the building and the greater the temperature difference, the stronger the pull. That incoming cold air at the garage level is what makes the garage door sound like a wind tunnel, and the pressure at the lower floors is what makes lobby doors hard to open.

In summer, the effect partially reverses. The air inside is cooler than the air outside, so the flow runs downward: air enters at the top and exits at the bottom. Buildings in Ontario therefore live with two directions of stack effect each year, which is why some comfort and fire safety problems appear only in certain seasons.

The Everyday Symptoms

Common symptoms of stack effect can include doors that slam or resist opening, whistling or rattling at large openings, and airflow through shafts. Building-specific mechanical or envelope problems can produce similar symptoms, so persistent issues should be assessed rather than automatically attributed to stack effect.

Weatherstripping, air sealing, and properly adjusted door hardware can help reduce unwanted air movement where those measures are appropriate. Any work affecting fire separations, smoke-control systems, or required door operation should be reviewed by qualified professionals.

The Fire Safety Connection

Here is why fire departments and engineers take stack effect seriously. During a fire, pressure differences and vertical shafts can influence smoke movement in a tall building. Some high-rise buildings use engineered smoke-control measures such as pressurization, but the exact system and testing obligations depend on the building's design and applicable Fire Code provisions.

The 2026 Ontario Fire Code amendments revised smoke-control inspection and testing provisions. While the code requires updated national standards, such as CAN/ULC-S536:2019, to set the basic inspection intervals (monthly, semi-annual, or annual), smoke-control systems can differ significantly from one building to another. Features such as stairwell pressurization, automatic dampers, and exhaust fans depend on the building’s original design. For this reason, Section 7.3 of Division B requires the specific testing conditions, sequences, and operating parameters to be confirmed through the site’s Fire Safety Plan (FSP) and engineering procedures.

What Residents Can Do

Residents can help by keeping suite and fire doors operating as intended and reporting doors that do not close or are unusually difficult to open. Some resistance may result from pressure differences, but a door that is excessively difficult to operate should be assessed rather than dismissed as normal physics.

Physics You Can Plan For

Stack effect is a natural air-movement phenomenon in tall buildings, but excessive drafts, door-force problems, or smoke-control concerns can also signal issues that need attention. Sealing, adjustment, and testing should be based on the building's actual systems and professional advice. Contact City Sites Property Management to discuss building-management concerns and request a proposal where appropriate.

For a deeper discussion of how the stack effect affects garage doors and air movement in winter, listen to the full #WeSpeakCondo episode with Sam Soltani of The Trace Group. The conversation adds useful perspective on building performance, maintenance, and resident comfort, and is a helpful companion to this article.

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