The Ideal House is a high performance home that has been built in Beachlands, Auckland, and showcases the lastest in sustainable design and materials. The family wanted to build an eco home that would be certified under the international Passive House standard. Low energy consumption lies at the heart of the Passive House standard and is achieved through high levels of insulation and an airtight building envelope, among other features.
The Ideal House has such good energy performance that it is considered a 'positive energy' home, where it produces more energy than it uses, via the solar panels. There is even enough energy to power up the family vehicle!
Additionally, this architectural home has a very impressive rating of 8 using the Homestar assessment tool. This tool goes beyond just energy efficiency and performance, and incorporates a wide range of other sustainable aspects from native plantings to accessibility.
But it's not just the eco features that make this home so impressive. The architectural and interior design features make for a light and airy home that is comfortable to live in and aesthetically pleasing.
Murray and Lee Ann Durbin, Annabelle (5), Tyler (8), plus their labraspoodle, Teddie. Murray is the General Manager of Knauf Insulation New Zealand, and Lee is the Education and Training Manager at the New Zealand Green Building Council. They also run a website for the house, www.idealhouse.org, which offers free information on the build and performance, as well as regular Open Homes.
We wished to build an energy efficient, comfortable, healthy home environment. To do this we built the home to Passive House standards and had this certified internationally, as well as undertaking the Homestar rating scheme.
A 254 square metre Passive Home. The home features four bedrooms, two bathrooms, two living areas, a small TV room and a double garage.
The section is 860m2. It is a 43m long by 20m wide section in a greenfields subdivision. We purchased with 5% down, about a year before the section was ready - off Spinnaker Bay Developments. We rented for all this time, and through the build process to realize our dream. It seemed like a lot of money at the time, however the Auckland market has continued to grow and in hindsight it was a sound investment. Should have bought two sections!
The section has views of the Gulf and Waiheke. Luckily the views have been kept as all the neighbours built single level and we built up at the front - and the gamble paid off. The land is relatively flat, and is now planted extensively in natives and fruit trees, with substantial veggie gardens.
We first chose our engineers, Paula Hugens and Denise Henkenhaf from EZED in Queenstown. They were responsible for the Passive House design and certification as well as the structural engineering. They then recommended us to S3 Architects, and Stephen Smith and Matt Wilson completed the working drawings for the home, working in closely with Paula and Denise.
Our original ideas came from a Senior Lecturer at The University of Auckland, Paola Leardini. Paola and her partner Manfredo were passionate about Passive Houses, and visited the land when it was still being developed and did some initial concepts. We wanted a light and airy home, with lots of open spaces, and a master bedroom on a second level away from the rest of the bedrooms. We got all we wanted, plus more. S3 designed in an extra-high ceiling stud height, which created some amazing spaces and is one of the best features of the home. The exterior is perhaps a bit more modern than we originally wanted but has grown on us.
We liked the Scandinavian feel of light coloured walls, and light bamboo flooring. It rains so much in Auckland we wanted a home that felt light and airy even on dark cloudy days - and it worked. The concept of bamboo came from visiting an Eco Show home in Chicago which had tens of thousands of visitors pass through its doors, and the bamboo looked like new.
We approached all the major building companies and group home builders in our area with our concept plans, and a presentation on Passive Houses but none of them wanted to take on the project. It was too far outside their comfort zone. We ended up selecting a local building company, Palladium Homes, who build about a dozen homes a year.
The home was completed August 2014. It took 6 months of planning, design and engineering, and 9 months of building. We lost 2-3 months as we changed our window joinery last minute to imported PVC from Europe, and had to re-apply for our building consent and wait for these to arrive. It was worth it.
- Heat exchanged ventilation: A Passive Haus certified system from Germany, called Zhender.
- uPVC windows with triple glazing, imported from Europe.
- Airtight products, such as Intello wrap and tapes from proclima to ensure the home passed the strict Passive House test of less than 0.6 air changes per hour at 50 pascals.
- 32 photovoltaic solar panels, which at 8kW allows the home to produce around twice what it consumes. There is no battery pack, and excess power is fed into and purchased back from the national grid.
- Very high levels of insulation in the foundation, walls and ceilings. Insulated with Earthwool glasswool.
- Extra-high ceiling stud height.
- 50,000L capacity for tank water to be collected from the roof, pergola, and the terrace about the garage.
Palladium provided a project manager, but we also did a lot of the project management ourselves for the eco features.
We stopped by the building site most evenings to check on progress, and to tidy up after the various tradesmen and sort rubbish. Recycling and site management are taken into consideration towards the Homestar rating, so we wanted to stay on top of this. Even though we placed labeled bins around the site, rubbish was invariably put into the wrong places. We have learnt for next time to get everyone on board with us to start with, and perhaps place some incentives (or penalties) in place to save us time. The end result was great though, as we reduced the original budgeted six skips to one, and picked up maximum points for the Homestar rating.
As mentioned, the largest challenge was keeping the site clean and sorting all the rubbish to upcycling and recycling. Additionally we had issues with our bank wanting frequent valuations so we could draw down on our mortgage - but our builder's contract did not line up with the valuations, leaving us short. We just about ground to a halt at one point due to lack of cash, so we changed banks and refinanced with Westpac who were incredibly supportive (and require less costly valuations) and saw us through to the end of the build.
We were adamant that we were going to build a Passive House as close to 'normal' New Zealand construction methods as possible. This included wanting to use aluminium joinery as it is the most common, and often most cost effective. The home was designed with thermally broken aluminium, and we even had our Building Consent issued with this, but through months of engineering and working with local manufacturers we couldn't get the product to work with the strict Passive House requirements. Our options were either wood or PVC, and we opted for PVC for better value.
In the end we sent the architect away for a weekend to a Hotel (away from his family) so he could re-draw the plans with the new windows so they could be sent back into Council. However the delay was worth it, as the quality, cost effectiveness and performance of the joinery and glass out of Europe exceeded anything we could find locally.
It's quiet, light and airy, yet warm and comfortable. We adore the high studs, and super-high area in the kitchen. Our son loves his Mezzanine. We range from 20-25 degrees all year without requiring heating, and humidity sits 20-30% lower than normal thanks to our heat-exchange balanced ventilation system.
- Consider acoustics. Given we went for mostly hard surfaces, we could have built in more acoustic treatments, and we will now have to retrofit some of these after.
- Ensure you have "extra" in your budget to allow for unforeseen circumstances (such as having to leave scaffolding up longer than planned).
- If you want a high performance home, work on design (both form and detail), high levels of insulation, air-tightness, quality window joinery, and balanced ventilation.
- Consider starting with an engineer and then finding an architect or draftsman.
We used to do open homes once a fortnight, and now it’s about once a month – however we do tours on request. We’ve had the interior decorators guild come through once, a group of female architects who tour homes, and we participate in International Passive House days etc.
The open home dates are posted on our website www.idealhouse.org. The last one before Christmas is on the 13th December from 1pm to 3pm.
Alternatively you can do a virtual 45min tour of the house and all it's eco features by viewing the Ideal House video tour here.
- Designer / Architect: Stephen Smith and Matt Wilson, S3 Architects
- Engineer: Paula Hugens and Denise Henkenhaf from EZED Engineering
- Building Company: Palladium Homes
- Plumber: All Go Plumbing
- Tiles: Tile Warehouse
- Building Product Supplier: ITM
- KitchenTang Ming Kitchens, East Tamaki
- Foundations: Batten & Cradle, and Firth
- Wall linings: Villaboard from James Hardie (hallways, wet areas, garage), and GIB from Winstone Wallboards
- Roofing: Colorsteel, by Dimond and Installed by Right Now Roofing
- Window & Door Joinery: Aluplast PVC Series 8000 from Warm Windows, East Tamaki
- Driveways & concrete: Firth enviropavers and eco certified concrete
- Finance - Westpac
- Insulation: Earthwool Glasswool insulation from Knauf Insulation