On paper, the brief for 700haus seems pretty straight forward. But as it turned out for the designer, delivering a home that optimised site conditions while meeting client’s desires made the task of building this Trentham, Victoria residence a little more difficult.
The clients requested an energy-efficient and light-filled farmhouse that celebrated the site’s variety of vistas which includes an eastern outlook to Mount Macedon, southern views to a 100 year-old Blackbutt tree and a western panorama of the mountain plains of Trentham East—no northern views were sought.
Making it a little trickier is the fact that 700haus is based in the hills of Trentham East at an elevation of, you guessed it, 700 metres, which equates to a climate zone 7 (zone 8 is alpine) and means the house in question would have to stand up to heavy wind conditions.
For Timothy Ellis of Glow Design Group, who designed 700haus and also happens to be an accredited thermal performance assessor, the Trentham project became a case of materials or bust, and his choice of building products, in unison with his passive design, allowed him to create a home that was sustainable, comfortable and a celebration of the surrounding environment.
700haus achieved a NABERS rating of 7.8 for its climate zone which actually correlates to an 8.3 NABERS rating if the home was in Melbourne and a 9.2 rating if it was in Sydney. The home was also one of eight finalists in the Single Dwelling (New) category of the 2015 Sustainability Awards which was no easy feat considering it received a record number of entries with projects from Australia’s best designers.
A tick for sustainability.
The home is divided into three main sections, a living and entertaining pavilion at the north, a master bedroom and garage pavilion at the south and a middle bridge section which houses two bedrooms and a bathroom and connects the two pavilions.
The I-shaped floorplan orients with the various vistas from the hill top location and the majority of the home’s timber framed windows are situated on the east, west and southern aspects to create a home that frames the surrounding environment with walls of windows in every room.
A tick for views.
Its high thermal performance comes from a combination of material selection and passive design. Firstly, the slab is heavily insulated with polystyrene on its underside, around its bored piers and along the slab edge to increase its performance as the home’s major source of thermal mass. It is also hydronically heated by heat pumps which helps provide interior comfort for the clients in the colder months.
Ellis chose to double-stud the perimeter walls - which meant they could carry double the insulation - and used a heavy R6 bulk insulation in the ceiling cavity. Reverse brick veneer was also used on 700haus’ northern elevations to add thermal mass and all windows, glass doors and skylights are either double or triple glazed units.
No air conditioning is used throughout the home and Ellis claims that a variety of Big Ass Fans are all that is needed to keep the home comfortable during the summer months.
Beyond the thermal performance of 700haus, Ellis earned praise from the 2015 Sustainability Awards judges for his material sourcing program and “local-first” attitude to specifying tradesman.
Local trades were employed to reduce transport, the stone came from the nearby town of Castlemaine and the home’s magnitude of Blackbutt is also recycled and locally sourced.
The builder planted 270 Eucalypt Acacias around 700haus, waste is treated on site and all water is provided from massive 60,000 litre water tanks—every material and service was chosen through a meticulous selection criteria.
700haus shows that through a deep knowledge of the available and necessary building products, a sustainable home can be produced with local materials and without compromising on building performance.
Ellis and his firm addressed the challenges of orienting the building’s glazing towards unfavourable aspects by specifying double and triple glazed units. His material selection helped him harmonise the conflicting influences of site challenges and client desires.
KEY INTIATIVES
- Double stud walls built of renewable plantation timber with large amounts of insulation
- Reverse brick veneer northern walls
- Double and triple glazing
- 270 Eucalypt Acacias
- 64,000 litre storage tanks
- 7.8 Star in cold location 8.3 if located in Melbourne
- Local trades used including local stonemason
- Will be off grid when solar to shed complete
- Hydronic system via heat pumps
- Local stone was used by local stonemason to build double sided chimney
PRODUCTS
ROOF
Corrugated galvanized steel cladding, BlueScope Lysaght
WALLS
Corrugated galvanized steel cladding, BlueScope Lysaght
WINDOWS AND GLASS DOORS
Double and triple glazed units, BINQ
WATER TANK
Pioneer Tanks
INSULATION
Earthwool, Knauf Insulation
FANS
Haiku, Big Ass Fans Australia
OVEN
900mm freestanding oven, Ilve Appliances
PLASTERBOARD
CSR Gyprock
KITCHEN BENCHTOP
Caesarstone
