1 Yagoi Hamlet, Ecovillage

1 Yagoi sits mid-way up a hill at the Valley Terraces, Ecovillage, being serviced by a one-lane kerbless road that provides access to only about four homes. The streetscape presentation is evident from the main road long before this small access lane is even detected, as the home rises from the hill most predominantly on the low side, displaying a series of distinctive outdoor rooms. 

The first feature of the streetscape is the pronounced elliptical deck, anchored to the ground by a series of vertical handrail supports, providing both screening and glimpses of numerous water tanks situated under this expansive north deck. 

As the image of the house rises out of the ground, the feature of the yawning cantilevered deck roof cuts an idiosyncratic image in the sky, with a backdrop of a pop-up roof shading clerestory windows below and supporting photovoltaic panels above. 

Although the garage is evident at the very end of the journey, it is well hidden from the streetscape view until the point where the office entry, home entry and driveway all converge at ground level to offer accessible entry into the building.

With the Architectural and Landscape Codes of the Ecovillage being very strict on issues of earthworks, very little cut and fill being permitted, so addressing the hillside topography while still respecting a northerly solar orientation was the largest challenge. In order to present the home to the north, it needed to be positioned across the contours of the site rather than being able to run along with them. Combining this aspect with the need to provide both interaction with the ground as well as accessibility to all parts of the home provided a conundrum indeed.  The solution to our dilemma was to break the form of the home into two north facing pavilions, each running along the contour and being separated by a central deck that formed an elevated entertaining area, an entry and well as a ventilating breezeway. We then used the undulation of the land itself to provide an earth-ramp access to the lower deck and lounge area, which was designed to step down in response to the hillside.

The successful outcome of this home was due to the contribution of many individuals, not the least of which was the client, Ben O'Callaghan (now Cundall State Manager), who acted also as a project manager, but one who emphasised the sustainability aspects of the project over almost all others. Secondly, I would like to acknowledge our own design and drafting team, led by myself, Amy Degenhart, supported by Juliana Sigut and Hiro Nakamura. The builder, Jason Chinnick of Too Easy Carpentry was the other main contributor, and we all relied on advice from many specialists, including Chris Walton, the Ecovillage developer; Mark Wichlinski, the structural engineer; Eldon Botcher, the bushfire consultant; Martin Jackson, the landscape designer; Stewart McIntyre, the surveyor; Rob Norman, the Village Design Panel Chairman; and, finally, Victor Z Yanchenko, the energy certifier.

The value of design to this project is undeniably, as it is design that forms the skeleton on which to support the functional brief, the sustainability agenda and the aesthetic fulfilment. The cost of the project is relatively high on a square metre rate, about $2,300, due to the commitment of investment in environmentally sustainable products and procedures being distributed over the fairly modest floor area of 300m², including several generous decks and balconies.

1 Yagoi Hamlet incorporates over 100 individual environmentally sustainable features that make this house a role model for sustainable design, building practices and lifestyle. It is a house designed to incorporate the best of the currently available environmentally friendly design principles and products.

Achieving an Energy Efficiency rating of over 7 stars, this home requires virtually no heating or cooling due to its excellent passive solar design. An Ecovision metering system reports on all gas, water and electricity use (and solar energy generation) in real-time. The house aims to be carbon neutral in operation as it uses leading solar technologies, often feeding its excess power into the network power grid.

degenhartSHEDD has prepared a sustainable house design that not only incorporates the ultimate in passive solar principles, maximising its precise solar-north orientation, but also features optimally designed eaves and a suspended polished concrete slab in the northern pavilion for thermal stability. To take full advantage of these features, plentiful glazing has been provided to all northern elevations, including the clerestorey windows above the Kitchen/Dining Areas that are carefully positioned to allow sunlight to fall upon the polished concrete walkway that articulates the connection between the living rooms and the central breezeway. This fenestration has also been designed to ensure good cross-ventilation, with only two fixed double glazed  trapezoidal windows facing west, serving to frame the view of the large feature fig tree that is a major attraction of the property. 

The basic planning concept of this unique design is a proven degenhartSHEDD success formula, and features a central deck area that both serves as an entry as well as a link between the living and bedroom pavilions, a strategy that has allowed the house to nestle into the west-sloping hillside while still exploiting a predominantly northern orientation. An important result of this careful attention to detail in the site design is the ability to access all levels of the home without the use of stairs, by linking the various terraces of the home with an external curved ramped pathway. Although moderate in size, the use of the pavilion concept, complemented by the separate garage, has made this home appear stately within the context of the landscape.

Further solutions to sustainability challenges include the extensive use of low wattage fluorescent and LED lights, along with carefully selected energy efficient appliances. For hot water, the house uses an evacuated tube solar hot water system, coupled with an instantaneous gas hot water heater. Although this gas heater has been provided in addition to the solar heater, it is almost never needed, thanks to the superior energy performance of the building itself, enhanced by the generous insulation of floors, roofs and walls. In addition, the house proudly displays a creative range of recycled materials, including old barn floorboards, bridge posts and even old tram tracks used instead of new steel I-beams. Furthermore, it contains virtually none of the most environmentally undesirable materials, such as PVC or Volatile Organic Compounds (VOCs), as extreme care was taken with all the sealants and finishes. In terms of water harvesting, rainwater tanks provide for all water supply needs, and the house is also connected to a water recycling system that recycles all grey- and black-water for use in irrigating the native gardens and in the toilets. Another important bonus of this cutting-edge sustainable design is that energy-greedy appliances like air conditioners and clothes dryers are rendered obsolete.

Please also find following the specific sustainability elements featured in this home:

Ventilation: The house contains a living and bedroom pavilion separated by a unique and special covered breezeway that ensure the house will remain cool in the hot Queensland summer.

Water Harvesting Systems: The house can store 43,000 litres of water in rain water tanks and this quantity meets all potable water requirements. A centralised wastewater treatment system treats all grey and black water in the estate and returns it for use as irrigation on plants and for use in all toilets.

Special Garden Features: The garden contains only native species and food producing species, with a vegetable garden to provide local organic produce.

Materials: Recycled materials included old barn floorboards, salvaged bamboo decking, bridge posts, recycled besser blocks. HYNE T2 MGP12 environmentally friendly termite resistant plantation pine was used for the frames and trusses.  Also, virtually no PVC or Volatile Organic Compounds (VOCs) were used. Roofs are of light-coloured Colour Bond, and also contain R 3.5+ insulation, sisulation, while the floor is formed in pole-home constructuion techniques with a suspended concrete slab in an ochre colour (polished and no sealant required).  

Lighting and Appliances: Extensive use of low wattage fluorescent and LED lights, along with carefully selected energy efficient appliances. Sunlights have also been provided in bathrooms to reduce the need for artificial lighting.

Windows: High transmission, Low emissivity (low-e) glazing. Power Generation: 1kW Kyocera System Heating & Cooling: No Air-conditioners required. Rinnai 6 Star LPG Gas heater used on rare occasions.

Water and Space Heating: Evacuated Tube Solar – with instantaneous gas back up Energy Efficiency. Although one internal gas heater has been installed it is almost never needed, thanks to the superior energy performance of the building itself.

Rating: 7.2 Stars (Accurate)

This project has been used as the subject of a short documentary film on environmentally sustainability design, and has won an industry award (refer details below) as a result of its design principles and successful outcomes. These means of broadcasting the sustainability message to the wider community has been a major benefit of the project, reinforcing the good work that The Ecovillage--winner of over 30 industry awards itself--has instigated. The client himself has used these successes and the evidence that they provide to his commitment to a more sustainable world as a means to create his own personal brand, and that in itself has furthered his own career.

This home has won an industry award, the 2009 GreenSmart Energy Efficiency Award of the HIA-CSR Gold Coast/Northern Rivers Housing Awards, and has also been the subject of a short documentary demonstrating the process of designing and constructing an environmentally sensitive home.  The documentary is available for purchase on compact disk for a nominal cost of $25 for individuals and $80 for education/commercial purposes.

For more information on this home, please make contact with us or our client through the following websites:

www.yagoi.org and www.degenhartSHEDD.com.au

1 Yagoi Hamlet is located within the World Award-winning Ecovillage at Currumbin, Queensland, Australia.