When a fire breaks out in a high-rise building (18 m+), smoke is often a bigger killer than flames. It moves fast, fills escape routes, and blinds both residents and emergency services, turning a manageable fire into a major disaster within minutes.

That’s why smoke ventilation in high-rise buildings isn’t just a tick-box requirement — it’s a life-saving system. The taller the building, the greater the risk of vertical smoke movement, which makes safe evacuation incredibly challenging. From flats and hotels to office towers and hospitals, these structures need intelligent smoke control strategies that work in real-time and under pressure.

In this article, I’ll walk you through the unique challenges high-rise buildings face when it comes to smoke ventilation — and the practical solutions that can make all the difference. Whether you’re a developer, a fire safety consultant, or a building manager just trying to get things right, this breakdown will help you understand what works, what doesn’t, and what’s legally expected.

Let’s dive into how smoke behaves in tall buildings — and what you can do to stop it from becoming a deadly threat.

Understanding Smoke Movement in High-Rise Buildings

The Stack Effect

The stack effect is one of the most significant factors influencing smoke movement in high-rise buildings. It occurs due to the natural difference in temperature between indoor and outdoor environments it can also be effected by weather conditions such as pressure differentials created by high winds. 

The theory is that when a fire breaks out, the heated air becomes buoyant and rises quickly through vertical shafts like stairwells, lift shafts, and service ducts but can also cool down and drop as taken into account with the design of shopping centres .

This rising column of hot air creates a pressure differential that pulls smoke upwards — often much faster than people can evacuate. In poorly ventilated or older high-rises, this effect can cause smoke to spread in minutes, overwhelming the corridor and making escape routes impassable.

Understanding and controlling the stack effect is essential to ensure safe evacuation routes under ADB solution the goal is to keep the escape routes clear, particularly in tall residential towers and commercial office blocks.

Impact of Building Design on Smoke Spread

How a building is designed — especially its vertical and horizontal connections — can significantly affect smoke propagation. Features like:

• Stairwells and lift shafts
  
• Open atriums
  
• Ventilation ductwork
  
• Unsealed service risers
  

…can all act like chimneys if not properly compartmentalised or fitted with smoke control systems.

For example, an open lift shaft without pressurisation can rapidly funnel smoke to upper floors, putting residents and first responders at risk. On the other hand, buildings with effective zoning, fire doors, and automated smoke ventilation systems can contain and extract smoke before it spreads.

Good architectural planning — paired with smart mechanical systems — is key to limiting smoke movement and keeping escape routes safe in a fire emergency.

Unique Challenges in Smoke Ventilation for High-Rise Structures

Evacuation Difficulties

Evacuating occupants from the upper floors of a high-rise during a fire is no small feat. Stairwells quickly become congested, with the normal lifts are out of use or smoke has already spread through corridors. People with limited mobility or visual impairments face added difficulty, and panic can delay movement even further.

Without a reliable smoke control system, these escape routes may be filled with thick, toxic smoke — making safe evacuation nearly impossible. That’s why ventilation plays a crucial role in keeping those paths breathable and visible.

Vertical Fire and Smoke Propagation

Unlike low-rise buildings, high-rises contain multiple vertical shafts — think lift wells, service ducts, and staircases — which act like chimneys during a fire. Heat rises quickly, pulling smoke with it. This effect accelerates the spread of smoke through multiple levels before fire doors or detectors can even respond.

If systems aren’t in place to block or exhaust this smoke, it can compromise every floor above the source of the fire — threatening lives and overwhelming emergency response.

Firefighter Access Limitations

Time is everything in an emergency, but in high-rise buildings, firefighters face logistical challenges. Reaching the source of the fire can take minutes — climbing stairs, locating the flat, and fighting against smoke-filled corridors.

Worse, without proper ventilation systems in place, the air can become unbreathable long before they arrive, making their job even more dangerous. And limiting the available time to fight the fire because they used there oxygen traversing up the staircase. These conditions can also limit their ability to rescue trapped residents on higher levels.

Complex Building Layouts

Modern high-rise buildings are anything but simple. Intricate architectural designs — with multiple wings, varied floor plans, and open atriums — can disrupt how smoke behaves.

Compartmentalisation, which aims to contain fire and smoke in one area, can become ineffective if not properly designed or maintained. If ventilation systems don’t adapt to the building’s unique layout, smoke may bypass these fire zones and spread further than expected.

Solutions for Effective Smoke Ventilation

CFD modeling is the normal way to see how your building will react to a 50Megga watt fire, it would be fair to say that all mechanical systems have been or should have been modeled to recreate the digital fire within the building to ensure the right size fans and ductwork cross sectional area has been calculated correctly to ensure the working pressures in pascals is achievable with the products selected  

Advanced Smoke Control Systems

All smoke vent systems of this type are now PLC controlled and can be described as Advanced, but ultimately create the same safe environment as a system reliant on relays and simple management controls 

Zoned Smoke Control

Zoning is one of the most efficient ways to control smoke movement. These systems divide a building into separate sections or “zones”, these are all relevant to the travel distances to relevant safety or known commonly as staircases each zone with its own smoke control strategy. In the event of a fire, only the affected zone activates, minimising the spread and preserving clean air in other areas.

By using pressure differences between zones, smoke can be directed away from evacuation paths, giving occupants a safer route to escape and firefighters better access to intervene.

Pressurised Stairwells and Elevators

Pressurisation systems are designed to maintain higher air pressure in stairwells and lift lobbies than in adjoining spaces. This positive pressure acts like an invisible wall, stopping smoke from leaking into escape routes.

If properly installed and maintained, these systems can provide safe evacuation paths even in fully developed fires. They’re particularly effective in high-rises where residents may need to descend multiple floors before reaching safety.

It is generally considered that all future 18 m+ buildings will incorporate pressurisation for fire fighting lift shafts and staircases with depressurised refuge areas for people who have a for example PEP personal evacuation plan 

Integration of Smart Technologies

Technology is transforming how smoke ventilation is managed. Today’s systems can include IoT-connected sensors, remote monitoring, and automated control panels that respond in real-time to changes in temperature or air quality.

Smart systems can detect a fire, activate fans, open vents, and even alert emergency services — all within seconds. By reducing the need for manual intervention, these setups dramatically improve response times and ensure consistent performance under pressure.

Regular Maintenance and Testing

Even the best system in the world is useless if it fails when needed. That’s why routine inspections, functional tests, and performance drills are so essential.

Building managers should have a clear maintenance schedule that includes checking:

• Ventilation fan functionality
• Weekly testing
  
• Pressure differential system accuracy
  
• Automatic vent activation
  
• Backup power sources
  

Regular testing ensures all components work correctly and gives peace of mind that, when a real emergency hits, your system won’t let you down.

Case Studies

High-Rise Residential Building Incident

In 2023, a 17-storey residential tower in East London faced a severe kitchen fire on the 9th floor. Thanks to a fully integrated smoke ventilation system designed in line with BS EN 12101 standards, the outcome was a controlled and successful evacuation with no casualties.

Here’s how it worked:

• Automatic Opening Vents (AOVs) in the corridors opened as soon as smoke was detected.
  
• Mechanical extract fans kicked in to remove smoke from shared areas.
  
• A positive pressure system protected the stairwell, keeping it smoke-free for emergency services who could then decide to evacuate if necessary.
  

This setup ensured clear visibility, breathable air, and a safe route available for over the occupants to exit the building if deemed a necessity.

At FTG Ltd, we’ve worked on similar high-rise residential projects, providing tailored smoke ventilation maintenance solutions that meet strict safety regulations while adapting to unique building layouts. Our team helps clients to maintain the smoke vent system ensuring systems work exactly when they’re needed most.

Commercial High-Rise Fire Scenario

Contrast that with a fire in a commercial high-rise office block in Manchester. A faulty printer sparked a blaze in a third-floor office, but the building lacked an automated smoke control system. Smoke quickly filled the central atrium and drifted into upper-level meeting rooms and corridors, triggering panic.

Here’s what went wrong:

• No active extraction system was in place to remove the smoke.
  
• Stairwells became compromised due to negative pressure.
  
• Manual venting delayed evacuation by several minutes.
  

The result was multiple cases of smoke inhalation, a full building evacuation, and significant operational downtime.

This incident highlights the critical difference a well-designed smoke control system can make — not only for safety but for business continuity and building compliance. Smart investment in ventilation isn’t just a legal requirement; it’s risk mitigation at its core.

Regulatory Framework and Standards

Building Codes and Compliance

High-rise buildings in the UK must comply with Approved Document B and standards such as BS EN 12101 to ensure safe smoke control. These codes set out clear requirements for smoke ventilation, venting strategies, and system testing. Compliance isn’t optional — it’s the legal foundation of fire safety planning.

International Guidelines

Globally, smoke ventilation in high-rises is approached with varying stringency. For example, the NFPA 92 standard in the US provides detailed guidance on smoke management systems, while European codes lean heavily on EN standards. Understanding how these systems compare helps ensure that best practices — not just minimums — are followed.

Future Trends in Smoke Ventilation

Innovations in Ventilation Technology

Smart systems are becoming the new normal. From IoT-based sensors that adjust airflow in real-time to AI-driven alerts that activate venting zones based on fire location — tech is making smoke control faster, smarter, and more reliable than ever.

Sustainable Building Design

Modern architects are now blending fire safety with sustainability. Natural ventilation, solar-powered backup systems, and green materials in ducting design are all on the rise. The goal? Safer buildings that don’t compromise on energy efficiency or environmental responsibility.

Conclusion

Smoke ventilation in high-rise buildings isn’t a nice-to-have — it’s an absolute necessity. From the unpredictable spread of smoke due to the stack effect to the complexities of modern building design, there are plenty of challenges that can compromise occupant safety if not handled correctly.

But as we’ve seen, there are practical, proven solutions. Zoned control systems, pressurised stairwells, smart technologies, and regular maintenance all play a role in protecting lives and complying with fire safety standards.

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Building owners, developers, and safety professionals must prioritise smoke ventilation systems that are tailored to their structure’s layout and risk profile. Staying informed, investing in modern solutions, and working with trusted experts can ensure your high-rise building isn’t just compliant — it’s truly prepared.