Can fire resistance and sustainability coexist?

With climate change causing higher temperatures across the world, there is increasing emphasis on sustainability in the built environment. But, as the Grenfell Tower disaster showed, initiatives to improve sustainability and energy efficiency can sometimes undermine effective fire safety. So, can sustainability and fire resilience coexist?

HAJNAL NAGY

FPA Australia

Sustainability features highly in modern building design, and architects and engineers are keenly focused on the efficient use of energy and materials to reduce a building’s footprint.

While the fire industry has been largely on the periphery of some of the debates, there is a growing call for the sector to improve its own services and to adjust its strategies to deal with any increased fire risk arising from these new designs.

But there is an ever-present tension between environmental sustainability and safety that must be balanced so people can continue to be protected along with the planet.

When principles collide

The Grenfell Tower fire arose in part from this tension between sustainability and safety. An apparent desire for greater, cost-effective energy efficiency saw poor construction methods and the use of cheap, combustible cladding panels that, when ignited, caused the fire to spread rapidly.

The incorrect use of the panels, and insufficient strategies to mitigate their risks, potentially exacerbated a disaster that started with a faulty fridge.

Using panels with a fire-retardant core, at an increase of only £2 per square metre, would have reduced the risk to the building occupants; thus the cheaper version installed on the tower effectively put construction savings and energy efficiency concerns ahead of safety.

Clearly, builders and designers need to look more holistically at their designs, so that they do not only achieve environmental goals, but also ensure buildings and their occupants are protected.

The push for sustainability

Many people equate the sustainability of a building’s design with its ability to deliver energy efficiency or reduce embodied carbon.

But sustainability has long been defined as having three pillars— economic, social and environmental— and a focus solely on environmental concerns could ultimately lead to all three pillars being undermined.

This is why fire resilience is of paramount importance and why it should be central to any design.

Without fire resilience, any blaze could: „ allow smoke, toxic gases and particles to contaminate surroundings and have adverse effects on people’s health „ have a damaging effect on the community, disrupt public services or social activities or destroy critical infrastructure „ damage resources and infrastructure, causing financial loss both for businesses and occupants.

The construction of fire-resilient buildings can reduce these impacts and limit the disruption fires may cause, minimising the need for repairs or reconstruction.

At a time when society is experiencing increased demands for resources, it is essential that designs seek to protect buildings from fire.

Put simply, a drive for sustainable infrastructure and green technologies should not be allowed to place buildings and occupants at higher risk.

PHOTO: 123RF

A need to shift regulatory thinking

Current regulation looks at fire protection as a means for getting occupants out safely and preventing the spread of fire to neighbouring buildings.

This position is relatively shortsighted, as it does not consider the impact on the owners, occupants and the broader community of assets being destroyed.

Protecting a property in such a way that minimises damage caused by fire will allow an owner to repair it, rather than having to knock it down and rebuild.

While designers increasingly consider environmental sustainability as a value-add to any building, not much thought appears to be given to the loss of that value if a building burns down.

Fire safety and sustainability do not have to conflict, as they share common goals: protecting people and the environment, and minimising resource use.

So, fire resilience should be seen as an integral part of sustainability when developing policies, regulations and sustainable building rating schemes.

How do sustainable materials compare to traditional materials?

Some sustainable materials, systems and techniques—particularly in lightweight construction, insulation or ventilation—are emerging as potential fire hazards.

For example: „ composite wood joists often have considerably thinner web sections than traditional sawn lumber members, which reduces their inherent fire resistance „ the metal gusset plates used to connect engineered wood trusses can deform when exposed to high temperatures, which can contribute to early failure of the truss „ insulation materials like rigid foam insulation, spray-applied foam insulation, structural integrated panels, exterior insulation and finish systems and foil insulation systems methods may help to reduce energy costs by reducing ‘leaks’ in a building, but they can contribute to fire spread and increased smoke production „ airtight construction can create abnormal conditions during a fire event, which may encourage fire spread and backdrafts „ insulated concrete forms used in insulation, made from expanded polystyrene, are often flammable and can contribute to fire „ building systems, such as natural ventilation, can create an obstacle for firefighters trying to control smoke movement.

There are many alternative methods and materials that can help to reduce these risks and that should be considered. For example, fibreglass or mineral wool are naturally fire resistant but are still effective insulators.

Alternatively, better fire protection systems should be used to control and suppress a fire and account for the increased threat.

Fire sprinkler systems are one effective method for mitigating these risks, by managing the conflagration, keeping fire from damaging lightweight building materials and potentially preventing a collapse. The use of sprinklers can also keep a fire under control for a much longer period, giving firefighters more time to attend the site and extinguish the blaze.

As the Grenfell Tower fire showed, however, such solutions need to be carefully planned, designed and installed so their ability to protect a building is commensurate to the perceived risk.

The question at hand

Can fire resistance and sustainability coexist? Of course they can.

Designers will continue to want to design environmentally sustainable buildings, and they can easily do so, but they cannot forget about fire safety in the process.

Protecting a building is good way of improving its sustainability. The use of natural construction materials, greater insulation and low carbon heat options should not be at the expense of effective fire performance, but they should be protected by it.

After all, a building that is designed to withstand the potentially catastrophic risks of a fire will keep standing and continue to operate. What better way to preserve the benefits gained from sustainable construction?