Renovator’s delight
From Sanctuary magazine issue 5.
When Nash and Meaghan Popp bought a Californian Bungalow in the inner Melbourne suburb of Thornbury in 2001, it was a typical renovator’s delight. “It was so dark in here, you had to turn the lights on even in the middle of the day,” Meaghan remembers. “There were holes in the floor and flaking plaster and lathe on the walls.” In 2004, the Popps wanted to build an environmentally sustainable extension to increase the building’s light and reduce its operational energy use. They encountered more difficulties than they had anticipated.
“You must remember that four years ago, to build sustainably was still a bit freaky,” recalls Steffen Welsch, a local architect who the Popps contacted after they had seen his advert in the local newspaper. “There has been a significant shift in the past four years, but at the time we faced many hurdles and expenses due to the lack of experience and resistance to new ideas among builders, suppliers, installers and so forth.”
Steffen’s launching pad for planning the extension was to maximise light by capturing as much available sunlight as possible. The challenge was that the backyard faced south (in other words, received little direct sunlight) yet this was where the extension had to go. To overcome this, Steffen built an external courtyard between the existing house and the new extension. Thanks to its northern orientation, the courtyard receives sunlight all day, which in turn enters the living area (in the extension) through double-glazed windows. The kitchen, which links the old house to the extension, has a lower ceiling than the adjoining dining room. A row of north-facing windows fills the wall space between the two ceilings and these admit light into the dining room even during the winter months when the sun is lower in the sky.
In addition to a horizontal extension, the Popps built a second storey. This created fresh opportunities to reduce the building’s operational energy use. Windows were put in at strategic locations in the stairwell and upstairs to facilitate passive cooling: when night time creates cooler air currents, the stairwell acts as a heat shaft by drawing warm air from downstairs to upstairs, where the warm air can escape through the open windows.
As a consequence of building a second storey, the Popps made an aesthetic decision to install slanted loft-style ceilings in the upstairs rooms. These turned out to have a practical benefit because the north-facing roof is the perfect spot to mount solar photovoltaic panels. Consequently, the roof was built at a pitch to maximise solar access for the panels. Nash says that merely having the 1kW solar system has helped to make the family more conscious of, and conservative in, their energy consumption. “Even our two year old son, Xavier, turns the lights off when he leaves the room!”
Steffen observes that the house is “a good-looking building that doesn’t necessarily identify itself as a sustainable building, because it doesn’t look low or high tech; it just looks good.” Perhaps no feature of the house illustrates this more vividly than the facade of the upstairs extension. Slender, elegant timber battens run horizontally along the exterior of the north-facing walls, which face the street. The distance between each slat has been specifically gauged in order to let winter sun through (to warm the walls) and to keep summer sun out (to keep the walls cool). The effect is visually arresting and, simple as it is, puts a contemporary spin on this Californian Bungalow while simultaneously helping to regulate the internal temperature upstairs.
Rammed earth was used for the extension’s central wall as well as the east-and west-facing external walls. Rammed earth has a high thermal mass, meaning it holds heat well, only releasing it when the surrounding temperature drops. The walls have been insulated on the outside to improve their insulation value and aside from their excellent thermal mass, the rammed earth is a strong aesthetic feature of the house’s interior. The walls are a sandy colour, with traces of mica that glint in the sunlight. There’s a textural quality to the surface and it’s easy to see why Meaghan doesn’t want to hang paintings on these walls.
