2014 Residential Winner

Three out of four New Zealand homes are failing to meet sensible energy-efficiency standards, endangering the health of the families who live in them. The Bishop family wanted to find a healthy alternative, and consulted with designer Solarei and polished concrete contractor Polished Concrete Ltd., to build a passive solar home that takes advantage of site, climate, and materials to minimize energy use.

The resulting design is a bit like an old sawtooth-shaped factory roof—but smarter! A series of stacking sawtooth roofs capture every possible bit of sunlight reflected from polished concrete floors and precast concrete walls during winter, and then naturally exhaust warm air through a series of clerestories during summer.

Polished Concrete provided consulting during the early stages of design because:

The house relies heavily on exposed, insulated concrete slabs and large, insulated, vertical precast concrete walls for solar gain and heating during winter.

  • The concrete floors work as one huge thermal mass, collecting the warmth from the sun and releasing it at night so no additional power source is used.
  • The Bishops wanted a stunning yet functional floor that would be both environmentally conscious and robust enough to handle an active family with two young boys.
  • The concrete floors cover a very large part of the Bishop home. After several consultations, and keeping client wishes at the forefront of decision-making, the contractor finalized details such as mix design, slab design, grinding methodologies, and staging of work including proper procedures to protect the slab. The contractor and designer agreed to use the Husqvarna Hiperfloor concrete surface polishing system because it is hard-wearing, long-lasting, requires minimal upkeep and maintenance, and the Bishops liked it.

    The polishing crew tackled the floor in three stages:

    1. Grinding 3-5 mm to expose the aggregates just seven days after the first pour.
    2. Once weathertight, they polished the floor to an 800-grit finish, producing a beautiful glossy satin appearance. At this point, the floors were covered with breathable floor protection to keep them safe as the remainder of the house was built.
    3. Though in constant contact with the family, the contractor was not able to finish work until 12 months after polishing. The crew sealed and burnished the floors to spec, leaving the home environmentally sound and aesthetically devine.

    The 2906-square-foot home sits on a 1.5-acre property north of Auckland, New Zealand. From the initial idea to final move in, it took three years to complete the project.