Aluminium: The best for balconies?

With combustible materials banned in the external walls of high-rise buildings, the industry has had to adjust to a new design environment, however as AliDeck’s Richard Izzard explains, it hasn’t always been a smooth transition for balconies.

In the wake of the Grenfell Tower fire, and following the Hackitt Review, the specification of non-combustible construction materials in the external envelope of high-rise buildings is now mandated by a revised set of Building Regulations. 

With balconies clearly defined as “specified attachments” to the external envelope, the new, and more stringent regulatory environment requires balcony materials to be as fire safe as the rest of the envelope. This removes previously common materials, such as timber or composite decking, from the options available to specifiers.

Architects and specifiers however have rapidly embraced the new opportunities made available to them by metal balcony component systems that manufacturers have delivered to the market in response to evolving legislation. 

In particular, aluminium has risen to the fore, with manufacturers reacting to the situation by developing comprehensive aluminium systems for balconies, including decking boards, support joists, pedestals, soffit cladding, balustrades, and more.


To satisfy the new regulations, all materials must be certified to EuroClass A1 or A2-s1, d0 ratings. Aluminium easily achieves this standard, providing no contribution to fire and, when powder-coated to Qualicoat standards, no smoke emission and no production of “flaming droplets.” 

The compliance guarantee that these fire ratings deliver to specifiers is invaluable, allowing for essentially “off-the-shelf” specification of products, and providing peace-of-mind that proposals are robust and, most importantly, safe.

It has by no means been a smooth transition, though. As regulations began to evolve following Grenfell, and against a backdrop of the unrecognised implications for balcony design, many new and in-progress developments ‘fell between the cracks,’ and were completed with timber or composite decking across their balconies.

This has resulted in a huge amount of almost brand-new timber or composite decking needing to be stripped out and replaced with a non-combustible alternative, creating unnecessary additional expense and waste.


These new requirements and their associated costs and upheavals are appropriate responses to a genuine and inarguable set of problems within the construction sector. 

New legislation such as the Fire Safety Act and Building Safety Bill has helped to clarify the situation and move us towards a fire safe future.

An additional impact on the non-viability of combustible materials was highlighted by the External Wall Fire Review scheme. Developed by the Royal Institution of Chartered Surveyors (RICS) and the Building Societies Association, this scheme (more commonly known as EWS1) was designed to unblock the high-rise housing market by providing lenders with a standard fire survey for buildings above 18 metres in height. 

Changing Government advice in January 2020, however, broadened the scope of affected buildings to all multi-occupancy buildings of any height, leading to mortgage lenders requiring EWS1 surveys for many more properties than originally envisioned. This immediately resulted in a new log-jam and huge delays for homeowners and their buyers.

For buildings that fail the EWS1 survey, the only solution is for all combustible materials to be replaced with non-combustible alternatives. While many of these failed buildings have profound fire-safety issues affecting multiple aspects of the entire construction, there have been large numbers of buildings failing simply due to the presence of combustible materials only in the balconies. Lenders have simply refused to accept any risk when it comes to providing mortgages on properties that contain combustible components.

With comprehensive aluminium balcony systems available to directly replace combustible timber or composite decking, this issue has been relatively simple to resolve, albeit at considerable expense. It underlines, though, the importance of manufacturers developing complete and off-the-shelf compliant systems for architects and designers to not only solve these issues but to prevent them from occurring in the first place.


While the non-combustible nature of aluminium is certainly the primary driving force behind its rapid adoption as the go-to material for balcony components, there are other features that play no small part in its overall suitability as the ideal replacement for timber or composite in specification.

Durability, strength, weight, sustainability, and cost are all areas where aluminium performs exceptionally well compared to other non-combustible materials. It’s this comprehensive package of benefits that has made extruded aluminium systems the new de facto standard for balcony, terrace, and walkway design.

Aluminium is a strong and highly durable material, able to withstand decades of use with minimal wear, yet is only a third of the weight of steel, delivering a low structural load and allowing building designs to be streamlined. A further key property of aluminium is that it does not corrode or rust, even when exposed to wet environments over many years, and when powder-coated, it provides a ‘near-zero
maintenance’ solution, with just simple surface cleaning required. 

In plentiful natural supply and with expected product life spans of up to 60 years, aluminium systems are fast becoming the ideal solution for 21st century construction. As manufacturers continue to develop comprehensive aluminium product lines for all areas of a building’s construction, the material’s inherent benefits, and the hugely positive contribution it brings to fire-safety, will surely embed this material as the new standard in specification, and for much more than just on balconies and decking.

Richard Izzard is managing director of AliDeck