Fire-safe facades: Specifying for ventilation and fire safety

Post-Grenfell, fire-safe practices and construction materials have become a high priority in the UK construction landscape, bringing facade fire safety in particular into sharp focus. 

With facade design now under tighter scrutiny, and regulatory changes shaping how we build, specifiers and contractors must balance ventilation performance with fire safety when detailing wall penetrations for new building projects.

But how do you maintain air quality and energy efficiency without compromising fire compartmentation? The answer lies in early, informed specification and the right supply partners.

Why fire-safe ventilation specification matters

Ventilation systems — whether MVHR, MEV, or intermittent fan systems — often require ductwork to pass through fire-rated external walls. If not properly sealed, these penetrations can become weak links in a building’s fire protection strategy.

From compromised compartmentation to non-compliance with Building Control, poor detailing can lead to:

• Regulatory failures under Approved Documents B and F 
• Delays at project handover
• Post-build legal exposure
• Occupant safety risks

This is a potentially disastrous outcome for construction professionals tasked with balancing timelines, risk, and compliance across multiple sites. Not only does the finished product pose safety and compliance risks, but the reputational damage that could stem from poor final delivery would have far-reaching consequences.

What the regulations say

Approved Document – Fire safety 

Ventilation strategies must not undermine fire resistance. That’s the central tenet of Approved Document B, which states that:

“The building shall be designed and constructed so that the unseen spread of fire and smoke within concealed spaces in its structure and fabric is inhibited.” [Clause B3(4)]

“Where ducts pass through fire-separating elements, suitable fire-stopping or dampers must be installed to maintain the integrity of the element.” [Clause 10.1]

“Openings in external walls should be limited to reduce the potential for fire spread, particularly where a building is in close proximity to others.” [Clause 9.2]

These clauses have direct implications for ventilation. Wall penetrations, especially those involving plastic ducting, can create concealed routes for fire spread unless correctly sealed with tested and approved products like intumescent collars or fire dampers.

Approved Document F – Ventilation

While fire safety is paramount, Approved Document F requires that efforts to seal buildings for thermal and fire performance do not inadvertently trap pollutants and impair indoor air quality:

“Ventilation systems should work effectively and provide adequate air flow to maintain good indoor air quality, even in airtight homes.” [Clause 1.2]

“Where air-tightness is improved... mechanical ventilation should be considered to avoid issues such as condensation and poor air quality.” [Clause 3.15]

These clauses mean that any sealing or firestopping activity around wall ducts must not obstruct airflow and that ventilation strategies must be revalidated if facade or fabric alterations are made.

Building Safety Act: A new era of accountability

The Building Safety Act adds significant weight to the compliance landscape, particularly for higher-risk buildings (HRBs), such as multi-occupancy residential blocks over 11m. 

Under Section 38, the Act introduces the “Golden Thread” requirement:

“Accountable Persons must keep and maintain prescribed information about the building’s design and construction that is necessary to keep it safe.”

In the context of ventilation and facades, this means:

• Clear documentation of all wall duct penetrations
• Evidence of tested fire-rated systems
• Installation certification for intumescent firestopping products
• Validation that ventilation and fire systems work in tandem, not in conflict

Future Buildings Standard and system integration

The Future Buildings Standard mandates low-carbon, high-performance envelopes. As buildings become more airtight and thermally efficient, the challenge is ensuring that ventilation systems are energy efficient and safely integrated into fire-resisting elements.

This is particularly relevant in the context of:

• MVHR systems with external terminals
• MEV extract routes through insulated external walls
• Facade constructions using new non-combustible cladding systems

Ultimately, the message from regulations is clear: facades must breathe safely, but not burn.

Common fire-rated facade ventilation risks

Here’s where problems frequently arise when it comes to facade fire safety:

• Non compliant MVHR or MEV wall terminals as part of a fire-rated system: Using terminals or grilles that are non compliant as part of an integrated, fire-rated assembly can lead to failures in compartmentation, even if other components (like ducting) are compliant. Fire resistance relies on the system as a whole, not just individual parts.

• Improvised duct seals using unapproved materials: On-site installers sometimes substitute proprietary firestopping solutions with general-purpose sealants or foam fillers, which often degrade quickly under heat. These materials may appear sufficient, but lack the expansion properties needed to block fire and smoke during a blaze.

• Oversized wall openings with inadequate sealing: When core drilling exceeds the minimum size required for the duct, and is not backfilled correctly, the resulting gap allows for rapid fire spread. A 10mm annular gap around a duct might seem minor but can allow flames to bypass even the best fire-resistant duct.

• Poor coordination between facade and M&E design teams: When mechanical ventilation routes are designed in isolation from facade build-ups, penetrations may clash with fire barriers, insulation zones, or external finishes. This results in last-minute compromises that often ignore fire safety detailing or require costly rework.

These aren’t just theoretical issues. Building Control officers on site see them daily, and the Building Safety Regulator is increasingly scrutinising them for high-risk developments.

Best practice: How to specify ventilation through fire-safe facades

Early, integrated specification is key to avoiding these risks. Here's what it looks like in practice:

✅ Use fire-tested ductwork systems

Ensure any terminal, grille, or louvre breaching the facade is tested as part of a complete assembly,  including duct material, sealants, and fire collars.

✅ Specify intumescent products

Install intumescent sleeves or collars around plastic ducting that expands under heat, sealing the void in the event of fire.

✅ Choose slimline terminals

Low-profile MVHR/MEV terminals reduce facade disruption and can be easier to seal with fire-rated compounds.

✅ Document everything

Keep product certifications, testing data, and installation instructions ready for Building Control sign-off. Make documenting and maintaining a clear paper trail a priority throughout the building process.

Titon’s fire-conscious ventilation systems

At Titon, our ventilation system products proactively account for fire safety. 

Whether you’re designing a high-rise residential scheme or a tight-plot housing site, we support you with:

• Fire-rated wall duct terminals, designed for safe facade penetrations
• The market-first Titon FireSafe® Range, designed for powered ventilation systems, offers low resistance to airflow and high resistance to fire
• SAP-listed, ISO9001-accredited products for compliance peace of mind
• UK-based manufacturing for shorter lead times
• Technical support from the design stage through to installation
• Collaboration with facade contractors to ensure airtight, fire-safe detailing

Additionally, our MVHR and MEV systems are developed in accordance with Approved Document B and F requirements, with complete product testing data for Building Control approvals.

Conclusion: Save time, reduce risk, engage early

Fire-safe ventilation goes beyond compliance; it’s a trust-building measure the UK construction industry needs to truly future-proof buildings for both compliance and occupant safety. Proactive specification is the key to avoiding warranty claims, costly redesigns, and potentially disastrous fire risks.

Don’t leave fire safety and ventilation to chance. Partner with Titon early to ensure your facade penetrations are safe, efficient, and regulation-ready. 

Get our Fire Safety First white paper for more insights, or contact our team now for further information.