Kooltherm soffit insulation boards feature extensively in various areas of the Allianz Stadium, Sydney's new world class sporting arena that opened in August 2022.

Since its official opening, the Allianz Stadium is already proving to be the perfect showcase for Kingspan’s quality range of insulation products.

With a construction cost of $828 million, the new 42,500-seat public facility is built on the site of the former Sydney Football Stadium in Moore Park, home to the Sydney Roosters, NSW Waratahs, and Sydney Football Club. Allianz Stadium and the Sporting Club of Sydney were designed by Cox Architecture, who took on the challenge of creating a world-class, cutting-edge facility within this major public sporting and event precinct, providing a state-of-the-art sports and entertainment venue, and a wellness centre including gymnasiums, squash courts, swimming pools, sauna, and day spa.

Anna Brown and Alex York of Cox Architecture take a deep dive into their work on the project, including the pivotal role played by Kingspan Insulation materials.

“The Sporting Club of Sydney is a distinctively shaped building, with most of the accommodation located directly underneath the concourse – that massive walkway that serves as the main promenade into the stadium,” Anna begins. 

“The project features two Kingspan products – Kooltherm K10 G2 Soffit Board and Kooltherm K10 Plus Soffit Board’, she adds. 

“The K10 G2 foil-faced soffit board system features extensively within the main basement level of the fitness centre and was also used in the main stadium.”

“As most of the roof to the Sporting Club of Sydney is an open concrete structure with certain loadings, performance and operational requirements, we had to thermally insulate the slab from underneath. This called for a product that would need to be rigid and thin, meet the building code, and in certain cases, where there were no ceilings, present as a final finish.”

Anna and Alex’s commitment to creating a visually appealing solution was a natural fit for the Kingspan products. “Due to ceiling height requirements, we didn’t want to wrap the beams that were supporting the slab in insulation,” Anna explains. “To avoid doing this, we had to increase the under-slab’s performance above DtS provisions of the NCC and guidance on this was provided via a JV3 energy assessment model.  By increasing the K10 insulation’s thickness, we avoided having to place insulation everywhere on the underside of the structure.”

While Kooltherm K10 G2 soffit board proved to be the perfect solution in this case where there were ceilings to hide the foil base, Kingspan Kooltherm K10 Plus was used in spaces within the Fitness Facility, which lacked ceilings. “We used K10 Plus in the squash court area, for example,” Anna confirms. “The K10 Plus has a fibre cement base, so it’s capable of resisting a ball strike if one happens to make it all the way up there.”

Aesthetics were also a major consideration in this location, as they were throughout. “As there was no ceiling in the squash court, all exposed services were spray painted as part of the design of the room,” Anna points out. “For that reason, we needed a suitable insulation product that we could easily paint over to match the colour we had sprayed the services.”

Kingspan was also used in the Fitness Centre’s pool area, a challenging location, which placed major physical demands on the product. “We used K10 Plus over the 25-metre indoor pool, which has an outdoor deck above it,” Anna says. “All boards were butt jointed and sealed with appropriate waterproof sealant in this pool environment, and all exposed edges were foil-covered due to the pool’s high humidity and chlorine levels. This strategy also mitigated the risk of interstitial condensation forming. The K10 Plus was great in this context because we understand it to be a closed cell construction, therefore doesn’t absorb moisture, and there’s no risk of mould developing.”

The Sporting Club of Sydney’s unique demands were a natural fit for Kingspan’s impressive capabilities on multiple levels. 

“As well as looking great (given this is a high-end building), the insulation had to meet the NCC’s thermal and fire requirements,” she says. “Kingspan K10 products differ from spray-on insulation systems – because they are a mechanically fixed system, you know it will stay firmly in place, in one piece and present a smooth flat desirable ceiling surface.”

As Alex confirms, the Kingspan products performed beautifully throughout. “I’ve used Kingspan numerous times on other projects, and have confidence in it,” he says. “We provided a performance specification in terms of insulation requirements at the beginning of the project. The Kingspan product range complied with the thermal, acoustic and fire requirements while meeting our aesthetic criteria.”

Alex is decisive about the reasons for choosing Kingspan for this prestigious project. “We were chiefly interested in performance, and the Kingspan range gave us unique flexibility in this area,” he explains.

In this sporting centrepiece, the versatility, durability, and performance of Kingspan products speak for themselves.

Project details

Sector: Sports, Stadiums & Arenas

Location: Sydney, NSW

Completion Date: August 2022

Architect: Cox Architecture

Products: Kooltherm K10 G2 Soffit Board, Kooltherm K10 Plus Soffit Board

Photographer: Christopher Frederick Jones