Timber and MMC: Key considerations for brokers

As organisations adopt modern methods of construction (MMC) to meet sustainability targets, manage costs and speed up project delivery, it’s important to build a better understanding of building methods can affect risk, resilience and insurability.

Many new buildings now incorporate some form of MMC, with several factors driving this growth:

• Buildings can be delivered faster

• Factory-built components improve quality control, consistency and worker safety

• Construction and labour shortages are increasing demand for offsite manufacturing

• Carbon and waste reduction.

Timber construction continues to grow in popularity, driven by its sustainability credentials and carbon-capture benefits.

Many MMC buildings are designed to resemble traditional techniques, but the methods and materials used beneath the surface may be very different. This makes understanding the underlying construction critical when assessing risk and arranging insurance.

Timber frame construction

Widely used for housing, accommodation blocks, schools and care facilities.

Key concerns:

• Fire can spread rapidly through concealed cavities.

• Fires can track behind façades, making firefighting difficult.

• Timber exposed to water may swell, lose structural integrity and require replacement.

Cross-Laminated Timber (CLT)

CLT panels provide floors, walls and roofs in larger buildings.

Key concerns:

• While CLT chars on the surface during fire, there are concerns that bonding agents may fail under prolonged heat.

• This can expose fresh timber and contribute to ongoing fire development.

• Non-combustible linings can improve fire performance.

Glulam and Laminated Veneer Lumber (LVL)

These engineered timber products provide structural support while enabling large, open spaces.

Key concerns:

• Similar fire and water-damage vulnerabilities to other timber systems.

• Damage can extend beyond the visibly affected area, making assessment and repair more complex.

Beyond basic questions like the type of construction and which parts of the buildings are timber based, there are several further details worth exploring with the client.

Design, construction and insurance considerations

• Who will design, manufacture and install the timber system, and what evidence is available of their experience and quality-assurance processes?

• Will appropriate fire precautions be used during construction, and are equivalent controls planned for future refurbishment or maintenance work?

• Is detailed and up-to-date construction information available to share with the insurer at an early stage?

• Has the client considered how the construction method could affect repair times, reinstatement costs and the appropriate business interruption indemnity period?

• Are replacement components, compatible materials and contractors with the necessary specialist expertise readily available?

Ongoing fire, water and maintenance controls

• How are concealed cavities divided and protected to limit the spread of fire and smoke?

• What fire-stopping and compartmentation measures are in place, and how are they inspected and maintained?

• Are leak-detection systems installed in higher-risk areas such as plant rooms, kitchens and bathrooms?

• Is there a documented inspection and maintenance programme covering signs of water ingress, damp, decay, mould or timber movement?

• How accessible are concealed areas for inspection, maintenance and repair?

Asking your clients these questions can trigger valuable conversations and clearer insurance outcomes.