The Heights Whare Wānaka

A clear vision and a great team produced a beautiful Low Energy Building (LEB) home in one of New Zealand’s most challenging climates. The Heights Whare superbly illustrates that it’s possible to achieve a high-performance build on a modest budget.

This home is notably small, just 86m2. That’s the perfect size for its owners, who returned after five years comfortably living in a London apartment of a similar size. The initial challenge was finding a section in Wānaka without covenants; new developments in this part of the country usually have minimum size requirements, typically twice the size of this home!

The small volume makes it more challenging to achieve Passive House levels of performance. One owner is a Passive House consultant and she carried out the Passive House design, working closely with the architect. It was the first Passive House project either had worked on. It became clear that the LEB level of performance was a sweet spot with regard to occupant comfort, build quality and budget.

Despite the build spanning Covid lockdowns, with all the disruption that entailed, construction was complete in 18 months. The value of building a capable team and involving them early in the design phase is certainly one of the lessons that can be taken from this project. The builder, who has considerable Passive House experience, was engaged before a section was even found. Engineer Paula Hugens was brought in early too and her input into design helped identify cost and thermal savings. For instance, glazing areas were slightly reduced—a south-facing door became single not double width and north and west-facing windows became 400-500mm narrower. This saved money, improved performance and meant more wall space to hang things inside, an outcome the owner describes as win-win-win.

The builder’s experience with building high-performance homes in this climate also galvanised the design team to focus on mitigating the risk of overheating. Despite the cold climate, four wall-mounted panel heaters have no trouble in keeping indoor temperatures comfortable in winter. Air-conditioning isn’t needed. The concrete slab is insulated from below and the engineered timber floor is direct fixed to it. In this way the thermal mass of the slab helps buffer temperatures. Any slight increase to heating load is more than offset by how it helps with keeping summer temperatures comfortable indoors.

The timber frame construction was an obvious choice, given the contractor’s experience with this construction method. It’s also well-proven in Wānaka’s climatic extremes. Windows were from a local manufacturer, which delivered a winning combination of value, aesthetics and performance.

This house demonstrates vividly how intelligent and considered design can create buildings that are small but feel spacious. The higher raked ceiling in the living room came at some thermal cost but contributes to a perception of spaciousness. There’s a focus on multi-functional spaces; for instance the guest bedroom is used as an office and the large sofa only folds out to a comfortable queen-size bed when needed.

The small footprint wasn’t a sacrifice the owners made for the sake of affording high-performance; it was what they genuinely wanted. There were compromises made for the sake of budget: cedar cladding was an early and easy sacrifice and a separate entrance hall was lost but the function preserved. The couple used only a small portion of the budget allocated for things like tapware and other fixtures. The kitchen is charming and highly functional but unlike most Wānaka kitchens, granite benchtops don’t feature.

Their guests love the house, none more than a friend who uses a wheelchair and who appreciates the efforts made to provide universal access. It’s not an easy site in that regard, with the house sitting two metres above the road. But a ramp along the entire back wall provides access directly from the car park; doorways are slightly wider than standard and one shower is level access with blocking in place for grab rails. These small changes show considerable forethought and speak to the owners’ goal of creating their forever home, where a long time from now they can gracefully age in place.


Project Team

Architecture Virginia Barlow Architecture -

Passive House Design Sarah Allen
Davidson Building Limited
Sustainable Engineering

Passive House Metrics

  • Heating Demand29.2 kWh/m2/year
  • Heating Load16.5 W/m
  • TFA86m2
  • Form Factor4.4
  • Air leakage @ 50Pa0.6 ACH/hour
  • PER demand73.4kWh/m2/year

Passive House Database - TBA

Construction Details Average Values

  • U-value External Walls 0.20 W/(m2K)(R5.04)
  • 140mm wall with R4.1 Kanuf batts / Intello air control layer / 45mm Cavity with R1.2 Terra Lana batts / plasterboard
  • U-value Floor0.15W/(m2K)(R6.53)
  • Concrete slab on grade with 200mm Expol EPS platinum with graphite
  • U-value Roof 0.08W/(m2K)(R11.82)
  • Parallel chord truss and raked ceiling with 2x R5.2 Knauf batts / Intello air control layer / 45mm service cavity with R1.2 Terra Lana batts / plasterboard
  • U-value Glass0.52 W/(m2K)(R1.92)
  • Thermadura Climaguard Premium2 (4:/20/4/20/:4 90% Ar)
  • U-Windows0.9 W/(m2K)(R1.1)
  • Thermadura Natureline 90 timber frames
  • Ventilation Efficiency 85%
  • Zehnder ComfoAir Q350 HRV

East Elevation

West Elevation

South Elevation

North Elevation