Net Zero Carbon Hotel – voco Zeal Exeter Science Park

Designed with half the embodied carbon of a typical hotel, it will generate 100% of its electricity through photovoltaic roof and wall panels. Aligned with the 2050 Paris Agreement requirements and exceeding 2030 sustainability targets, the hotel balances environmental responsibility with guest comfort and luxury.

The project is scheduled for completion in December 2024, with an official opening planned for January 2025. Axter was tasked with designing a high-performance roofing system capable of supporting the extensive plant equipment and heavy mechanical traffic needed for the hotel's operations.

Selecting a durable, long-lasting roofing solution

The roof design needed to support substantial plant equipment and installations, including air handling units, inverters, heat source pumps, and numerous solar PV panels. These installations required penetrations through the roofing structure, which needed careful detailing to ensure system integrity and durability.

Axter proposed its Wilotekt^®-Plus hot melt system, which was selected for its durability and ability to withstand heavy plant loads and foot traffic. The hot melt system offers a 35-year guarantee and is a monolithic, structural waterproofing solution, with incredibly fast installation speeds.

The system incorporates insulation positioned above the primary waterproofing layer, providing an extra level of protection against damage from plant installations and activity from trade professionals onsite. Initially designed with a cross-laminated timber deck, the roof was later transitioned to a concrete deck, with Axter’s hot melt being the system of choice, which further helped reduce programme time and costs.

Axter’s services

Axter was brought on board to provide a full design and specification service for the roofing system. The team worked closely with Roofworx, the roofing installers, REDConstruction, the main contractors, and ECE Westworks, the architects, and the hotel’s team to ensure a smooth design process and installation.

“Our role involved conducting detailed rainwater and U-value calculations, authoring bespoke specifications through NBS Source, and providing hands-on support to the architectural team in developing custom details, ensuring that the solution was both practical and durable from design through to installation.”.” Natasha Kinnear AIoR, Senior Technical Sales Manager at Axter shares.

“Contributing to the design and specification of the flat roof for this hotel project required a highly collaborative approach, focused on delivering a robust and tailored system while adhering to relevant British Standards and providing long and meaningful guarantees.”

Why contractors trust Axter: A commitment to collaborative solutions

Axter and our hot melt system was initially introduced to the contractor through our long-term relationship with Roofworx, one of our Axtershield accredited installers.

However, it wasn’t just the strength of our existing relationship that secured the project. Axter's ability to offer comprehensive support – from detailed calculations to bespoke design solutions – ensured that the system we proposed was both technically sound and cost-effective.

Axter takes a consultative approach, prioritising what’s best for the project. This flexibility, combined with our extensive system knowledge, enabled us to deliver a solution that met the hotel's unique requirements while staying within budget.

Challenges overcome

One of the primary challenges during the project was the weather. The project began in March 2024, during a particularly rainy period, which delayed installation.

The number of roof penetrations required for plant equipment and the coordination of multiple trades created logistical challenges. Roofworx’s dedicated site manager played a crucial role in ensuring the installation proceeded smoothly and the roof was adequately protected from following trades once installed.

From a technical perspective, the project presented a unique challenge when it came to insulating the upstands. To prevent heat loss, the design required full encapsulation of the upstands, and due to sequencing constraints, we developed a hybrid solution combining an inverted roof system with a mix of inverted and warm roof upstands. This bespoke detail was a new approach, but it was successfully installed and performed well.

Axter’s collaboration with partners

Axter worked closely with all project partners to ensure a seamless and efficient collaboration.

“Being Bristol-based myself, like the architects, contractors, and roofing installer, allowed for frequent in-person meetings where design details were thoroughly discussed.” Natasha comments. “Virtual meetings supplemented these discussions to resolve any emerging issues in real-time.”

Natasha adds, “Our internal design team also developed bespoke waterproofing details, which were shared with the architects to be incorporated into the overall design. Regular site visits and walkarounds ensured that any challenges were addressed promptly, and all stakeholders reviewed and commented on the drawings, leading to a highly collaborative and solution-oriented approach.”

This close collaboration ensured that all design decisions were practical, compliant, and aligned with the project’s sustainability goals.

The Axter approach

Axter’s involvement in the voco Zeal Exeter Science Park project highlights our ability to deliver a high-performance roofing system tailored to meet complex, sustainability-driven requirements. Our hot melt system, backed by a 35-year guarantee, proved to be the ideal solution.

By working closely with the architects, contractors, roofing installers, Axter ensured a smooth and efficient design and installation process, overcoming weather challenges and complex technical details to deliver a durable, energy-efficient roofing solution.

For more information on how Axter's roofing systems can benefit your next project, please contact our team.