Home Building - Fisher & Paykel Appliances Headquarters

22 hours ago

3 min read

Products used: Nuraply 3PM, Nuratherm Tapered PIR, Nuralite Fixing Plates, ROCKWOOL

Contractor: Sansom

Situation

The Home Building, part of Fisher & Paykel Appliances’ new global headquarters, was designed to require a roof capable of meeting demanding thermal performance targets. The building features an unusual, curved shape in plan. The superstructure of the building incorporates an LVL diagrid with cross-laminated timber (CLT) floor slabs, selected for their low-embodied carbon properties. The structural design mandated a flat CLT roof, which provided a useful flat working platform during construction.

RTA Studio was responsible for Master planning, Architecture, and Interiors, while Naylor Love served as the Main Contractor, with Sansom acting as subcontractor for waterproofing. The project team, including façade engineers Oculus Building Science & Façades, required a roofing solution that satisfied insulation requirements and provided a straightforward pathway to compliance.

Challenge

Multiple warm roof build-ups were explored at a high level for costing purposes to achieve a high-performing envelope and reduce operational load. A key consideration was buildability and its effects on the programme. Drawing from previous experience with mass timber projects, both RTA and Naylor Love highlighted the importance of protecting the timber from moisture as quickly as possible.

To achieve the complex roof geometry, the tapered PIR layout was designed to facet in plan for maximum cost efficiency. A siphonic stormwater system was employed to eliminate external downpipes. Additionally, parapet heights were restricted by volcanic view shafts.

These challenges resulted in a roof design that falls to localized sumps. Furthermore, sump locations were governed by the ceiling arrangement on the floor below and the expected long-term displacement of the mass timber structure, as calculated by structural engineers Dunning Thornton. Nuralite revised the tapered layout six times to arrive at an optimal solution that met the growing list of design demands.

Solution

Traditional warm roof options with long-run roofing were explored during the early design stage, but voids between the flat CLT and pitched metal roof would have triggered requirements for access, ventilation, and fire suppression.

A warm roof system was specified using Nuratherm PIR Tapered insulation and Nuraply 3PM, a reinforced bituminous membrane. Nuraply PIR was chosen for its thermal properties, which provide a high R-value relative to its thickness and enable insulation targets to be achieved within a compact build-up. The density of the Nuratherm PIR eliminates the need for an additional cover board layer, reducing material and simplifying installation.

The membrane is laid to a one-degree fall, ensuring effective drainage while keeping the roof surface close to flat and minimising parapet heights.

Nuralite Fixing Plates were installed onto the Nuraply 3PM membrane to secure various services located on the roof, including the extensive solar panel array. Nuralite Fixing Plates provided the team with greater flexibility, facilitating services coordination, particularly the solar array and ducts, as they navigated the curved building plan.

ROCKWOOL was specified beneath the building as outsulation. The ground floor CLT slab was suspended above concrete plinths, allowing the subfloor space to enable stormwater to run off under the building into a pond in the central Oasis. ROCKWOOL was chosen for its capacity to dry, supporting moisture management and maintaining the thermal envelope. Its ease of installation was also considered important due to the limited access space in the undercroft.

Compliance is ensured through CodeMark certification supported by a compliance statement, providing the project team with documented assurance that the specified system meets the New Zealand Building Code and simplifying the consenting process.

Technical support was provided throughout the design phase, with Nuralite offering high-level costing information during the developed design stage. It remained crucial during the documentation and construction phases, as Nuralite maintained weekly contact, responded to queries as they arose, and coordinated with RTA and Oculus. This close collaboration ensured the project progressed smoothly as the tapered layout was refined and installed, resulting in a roof that delivers reliable thermal performance, compliant construction, and long-term durability.