It may be time to update the term “granny flat”, because there’s nothing old-fashioned about most “secondary dwellings” across Australia today. Changes in legislation have made it easier and more lucrative to build a granny flat out the back, and homeowners with a big enough plot of land are seeing not only financial, but also social and ecological benefits, as well as the aesthetic gratification of owning a decent piece of architecture.
Sydneysiders are now permitted to rent out granny flats to earn additional income streams, so the motivation to up the rental potential has led to a demand for high-end design. But it’s not all about rental levies; the benchmark is also being raised as customers become savvier about design and sustainable living.
Today’s designs are climate-responsive and make every last square-metre count, says Dean Maguire, interior designer at Baahouse (“Baa” standing for backyard affordability accommodation).
“Living areas should ideally face the northern aspect with louvre windows and large opening doors to suit prevailing breezes, as well as cross-ventilation and stack ventilation,” says Maguire. “High-level windows are good for heat escape and to let the most amount of light into a space.”
According to Ande Bunbury, who specialises in sustainable architecture, today’s small houses tend to have a higher cost per square-metre; clients want quality materials, chef’s kitchens and glass fold-out doors for a small-but-perfectly-formed space.
Such investment into the wow-factor, however, leaves little left over for behind-the-scenes costs such as plumbing, especially when granny flat projects require twin ensuite bathrooms and spa baths.
The demand for flexible draining solutions has increased since the mid-2000s, coinciding with the boom in granny flats, says Greg Waters, technical manager at Saniflo. “A reason for this is that most granny flats are existing structures or garage conversions and waste water drainage is an afterthought.
“For a granny flat you’d need to excavate to pick up all the waste water connections, then run those connections to an existing sewer point. The existing sewer might be 15-20 metres away or under concrete, and this all raises costs,” says Waters.
“Conventional drainage can take days if it has to be dug by hand across large distances – and accessing drainage pipes under concrete adds further costs. Sometimes there are additional services still, say if the plumber hits rock.”
A Saniflo system can ease unexpected money drain. It works by pumping waste water from the granny flat back to an existing sewer connection on the property. This provides design flexibility as waste water fixtures can be located anywhere, not restricted by the existing sewer location.
Waters recommends the Sanicubic 1 system for most granny flat applications. “The pump sits remotely below the fixtures and you run the kitchen, bathroom and laundry all into the one pump. It’s automatic, plug and play.”
The system uses smaller 20-40mm piping (compared to 100mm sewer pipes) that requires less excavation and can be easily navigated to the nearest sewer outlet. This saves installation costs as it is quicker than traditional drainage, usually a day’s work. “With a Saniflo solution, $5000 can potentially be saved on plumbing costs in setting up a granny flat,” says Waters.
Simple, low-cost and flexible are boxes also ticked by the kit home market, with options running the gamut from DIY flat-pack construction kits to turnkey modular houses such as the “Nano Home”. Typically with two-bedrooms, two-bathrooms, smart home wiring and ducted air-conditioning, a Nano Home can be installed in the backyard in five hours and costs about $140,000. DIY flat-packs can cost as little as $10,000.
Pre-fab is no longer a dirty word and options are increasingly avant garde. Brent Dunn of acclaimed Takt Studio architects has formed Joint Modular to focus entirely on semi-prefab modules.
“Not everyone can afford, or wait for, a completely bespoke small home, as it requires a huge input of time from design and building professionals,” says Dunn. “We felt that some of the lessons learned from years of inventing new buildings could be captured in a more repeatable building system.”
According to Maguire, the modern granny flat should include purpose-built and built-in cabinetry, should maximise vertical space and nooks with bench seats and snug areas, and reduce “wasted” space such as hallways.
Happily, open floor plans and a connection to the outdoors are more financially viable in secondary dwellings. “A small building with openings that are large, properly oriented and shaded can feel beautifully engaged with the outdoors,” says Sormann. “Access to sunlight and cross-breezes exceeds that in conventional homes.”
While the rules on renting out granny flats vary from state to state, it’s believed that changes to NSW’s laws in 2009 might have set a trend going forward.
“With home-ownership in the inner-city becoming increasingly out of reach,” says Sormann, “strategies to offset cost through shared living arrangements will become increasingly common.” In other words, granny flats are no longer old news.