Designed by Thom Craig Architecture and built by Bushnell Builders, this NZIA regional award-winning mini 'MegaTower' in Merivale is a mixed use office space that has become an iconic building in this well-known part of Christchurch. Located right next to Merivale Shopping Centre, the three storey commercial building is located on a tiny 27m² site. The building efficiently maximises the site and provides 62m² of space spread over the three storeys and mezzanine floor with a small bathroom and kitchen facilities. This type of mixed use facility is key to bringing people back into the city following the earthquakes, adding life to the area.

The Challenge

The site constraints and requirement to achieve compliance with the New Zealand Building Code (NZBC) airborne and impact sound clause and fire rating for this typology required a flexible, robust engineering solution that also took into consideration the history and future use of the site.

The Solution

James Hardie ExoTec Façade Panels have been cut into various shapes to provide an edgy, sleek façade. Architect Thom Craig's vision was to use innovative ideas and materials to create a strong street presence. The façade cranks back and forth to maximise the small footprint, and at three storeys, the building has some height and presence on the street.

Craig says, "The challenge was to plan and deliver a very workable and flexible typology on such a small footprint. There is also the engineering response in a three storey building with the history of earthquakes, taking into account wind-loading also."

In a build like this, the quality of materials and their ease of use was paramount. In addition to ExoTec Façade Panel, James Hardie RAB Board, and Secura Interior Flooring were specified in the build. The products work together to solve multiple problems, including meeting stringent fire resistance and acoustic building code requirements for medium to high rise construction.

Used together, RAB Board and ExoTec Façade Panel provide up to 60 minutes fire resistance rating. Similarly, Secura Interior Flooring, when used in a system, provides up to 60 minutes fire resistance rating and adheres to the NZBC airborne and impact sound clause.

The products also provided buildability benefits. The steel structure was craned onto site with RAB Board being used as a rigid air barrier, the ExoTec Façade Panels were then fixed to steel top hat sections.

Brad Austin, Project Manager from Bushnell Builders explains, "The ExoTec Top Hat cavity system is really sturdy. It's also a great system to install. You just drill a few holes and screw in place."

"RAB Board is also a great material to work with," Austin adds. "It made the framing rigid and created a weathertight building, which enabled us to start work on the interior, including the flooring."

Secura Interior Flooring has been used in both wet and dry areas on every floor. Resistant to moisture damage and rot, it is ideal for a hard-wearing commercial environment such as this.

Austin and Craig worked together to optimise Craig's plans for construction with support from James Hardie's technical team. Craig states, "We have a strong working relationship with James Hardie. We see them regularly, especially on R&D stuff when we're looking for a certain material or aesthetic. They have a good system of getting out on-site to help with technical support and follow-up."