A Little Whimsy

On slender, sloping blocks, concealed by frontages of traditional timber cottages, miniature pockets of wilderness unfurl across Brisbane’s subtropical landscape. In the backyard of this 10-by-40-metre site, banana and tropical palms establish the feathered edges to a broad canopy of a Tipuana tipu “Pride of Bolivia” tree, casting dappled shade over damp earth and sheltering a contented flock of domestic ducks.

Owners, Mark and Jitka, have long embraced their relaxed and rambling backyard, appreciating the perfect illusion of infinite garden it has created on their modest site. Preserving it was an important part of their brief to Phorm Architecture and Design when they initiated discussions about new rooms as an extension from the rear of their cottage.

During a design meeting held on a sunny patch in the garden, architects Paul Hotston and Yohei Omura made the unconventional suggestion to detach the backyard addition from the house and position it in the farthest and most under-utilised corner of the site.

Appreciating that this alternative would result in the structure having less visual and physical impact on the garden, Mark and Jitka embraced the proposal and, along with the change of location, came an important mental shift. “Once that happened all the rules were broken and that was so liberating,” Paul says. “It allowed us to prioritise the context and landscape over the program.”

Responding to the nuances of site and season, a rather radical triangular building diagram emerged. Two perpendicular sides were positioned neatly against rear and side boundaries with the broad hypotenuse stretched out to acknowledge the sprawling tree canopy nearby. This meant that the thinnest point of the building could be presented back to the house and that the longest edge could capture a north-eastern orientation and become “a canvas for the shadow of the tree.” So dedicated were the design team to minimising impact on the landscape that they digitally mapped the limbs of the tree to ensure that building and branches could intertwine.

Strengthening the synergy between building and tree was the idea that structure could serve as a kind of treehouse, becoming a place for leisure and recreation rather than a formalised set of rooms. The ground floor evolved into a verandah and floating platform in the garden, with provisions made for a future kitchenette concealed behind a removable plywood wall.

During construction, to the delight of keen climbers Mark and Jitka, a climbing wall emerged, reinforcing the concept of the building as a scalable structure. Upstairs a flexible room for guest accommodation with a modest bathroom was planned so that the whole could act as a semi-autonomous living unit suspended in the treetops.

The treehouse concept influenced both the design process and architectural outcome. “I believe we were thinking subconsciously about the duck house and the shed and how they’ve got a different tectonic – they’re more makeshift,” Paul says.

The team employed a cubbyhouse type of resourcefulness in the way that building materials were imagined and gathered. Birch plywood interior linings were purchased months before the contract was signed to ensure a competitive price. Each façade was considered an independent exercise in balancing ideas about economy and architectural expression.

The evolution of the western façade, addressing the neighbouring apartment and side street, was particularly interesting. A serendipitous meeting with a supplier resulted in the team securing a portion of the ochre-coloured metal cladding held in reserve for the Translational Research Institute, Brisbane. This enabled them to achieve “a glimmer from the street of something shiny against the dense greenery” at a fraction of the cost.

With a focus on capturing the daily and seasonal qualities of the garden, the building has become a highly adaptable place. “We like the idea that this is a relatively program-less building,” Paul says. “Houses aren’t static things and this idea that every room has a fixed purpose has become obsolete.” This has ensured a flexibility in programming that will allow the building to evolve over time and adapt to Mark and Jitka’s changing needs. This represents great value in terms of accommodation provided over such a meagre footprint.

Importantly the structure stands as not just an economical and efficient extension, but also as a spatial complement to the original cottage. It delivers, physically and metaphorically, “all the light and shiny and fun stuff.”

Whilst even the most modest extensions will inevitably compromise garden space, this carefully considered backyard addition achieves the opposite. Rather than consume the landscape, it liberates it, preserving nature whilst providing the shelter necessary for people and pets to luxuriate in it.

“Treehouse” seems an inadequate term to describe the structure. It is far more sophisticated and finely executed than its naive and haphazard suburban counterpart (a testament to the skill of Marvel Constructions) and yet it delivers all the sense of wonder and whimsy you would find in a garden folly. The spirit of place that is captured here invites family life into a fantastical garden world and awakens the joy and innocence of the childhood self.