Cath and George enlisted Energy Architecture to tackle the renovation after visiting John Maitland’s personal house one Sustainable House Day. John Maitland of Energy Architecture designed a new master bedroom with ensuite to the west, squeezed in a clever cantilevered study/guest room almost on the boundary to the east, opened up and reconfigured the lower level layout, and installed horizontal fixed shading over the huge north-facing windows. The living room was moved to the north to take advantage of the view, and now opens onto a new deck wrapped around the north side of the house.
Windows were added to the silos to bring in light and much-needed ventilation; they have deep brightly coloured box frames that provide shading and solve the geometric problem of installing flat windows in a curved surface. The splash of colour is deliberate: “I wanted the mode of the architecture to be distinct from the original,” explains John, of the alterations and additions. “I wanted to honour what the [original architect] had done, the very pretty aesthetic of it, so I chose colour, orthogonal shapes and horizontal forms, to contrast with the existing silver, round, vertical.”
The extension, housing the new main bedroom and its ensuite and walk-in robe, is in the form of a cube, tilted to follow the slope of the land. One side wall also slopes away from the perpendicular, providing an interesting interior element (and a furnishing challenge!).
To the north, a concertina floor-to-ceiling window can be opened right up to bring the sounds and scents of the bush inside; a roll-away insect screen keeps airborne visitors out and is surprisingly visually unobtrusive. On the sides seen most, the box is clad with Corten steel that will weather to a rusty patina. It was chosen for its texture and colour, and to echo the metal finish of the existing house without matching it.
John included a generous vent space behind the cladding to regulate heat transmission into the room. The study/guest room extension is also clad in Corten. Wedge-shaped to fit the space available, it hovers over the steep slope at the north-east corner of the house. Cath credits John with the inspiration: “I thought that corner was a full stop. It was John’s idea to put the guest room out there,” she says.
SUSTAINABLE FEATURES
HOT WATER
- Retained the existing solar hot water system: Edwards solar system. Manual electric boost
- Hot water pipes in the addition are insulated.
RENEWABLE ENERGY
- 2kW solar photovoltaic system, soon to be installed.
WATER SAVING
- Ri-Industries 22,000L underground rainwater tank plumbed to whole of house except kitchen
- Ri-Industries 2000L retention tank with Fielders first flush system, slow discharge to landscaping.
PASSIVE DESIGN
- Extensions oriented north for maximum solar gains; fixed metal shade devices added to existing window frames and external shading devices to northern living room windows
- Light-coloured roofing to lower heat loads
- Edmonds roof ventilator – TurboVentura
- Raven door seals throughout.
BUILDING MATERIALS
- Insulation: CSR Bradford hi-performance R5.0-6.0 ceiling batts, CSR Bradford Soundscreen Plus R2.5 to walls, Enviroseal wall wrap to external walls and Thermotec reflective unsulation and foam double layer to roof
- Walls: Onesteel Corten steel 3mm; James Hardie rendered fibre cement 9mm; Fielders Colorbond custom orb metal sheeting
- Roof Fielders Colorbond KlipLok700 roof sheeting.
WINDOWS & GLAZING
- Trend aluminium-framed, natural anodised, double glazed windows throughout new addition
- Full width flyscreen in the main bedroom by Freedom Screens.
LIGHTING
- Clipsal LED light fittings throughout.
PAINTS, FINISHES & FLOOR COVERINGS
- Dulux Weathershield acrylic to walls, eaves and fascias
- Deck oil is Livos, plant-based
- Sikkens clear finish to timber elements
- Universal Tiles porcelain tiles to ground floor living/utility areas
- Carpets to bedrooms and upstairs living are sisal natural fibre.
OTHER ESD FEATURES
- Home office so Cath can work from home and avoid commuting
- Low water garden – the garden currently comprises three raised vegie beds, which are being converted to wicking beds, and an assortment of local and or other hardy plants. No watering system is required
- On the lower side of the site similar water management work is underway, with indigenous grasses and shrubs.