Three mature trees were rooted to the centre of this site in Western Australia, but architecture firm MORQ managed to convince the owners to build their family house around the peeling trunks and burgeoning foliage (+ slideshow).

Located south of Perth in the town of Margaret River, Karri Loop House was constructed around one large Karri tree and a pair of Marri trees - both of which are indigenous to this region of Australia - after MORQ came up with a design that prevented them needing to be chopped down.

The single-storey residence has an H-shaped plan that wraps around the trunks of the three trees and also frames a pair of irregularly shaped courtyards.

To avoid disturbing the delicate shallow roots, the architects raised the house off the ground by positioning it on hand-placed steel tripod footings, rather than digging pile foundations.

Dramatic double-height ceilings and large windows were then added to the living room and master bedroom to "celebrate the presence of the trees" by offering residents views of the leaves and branches overhead.

"These trees, their root systems and their unstable large branches presented a challenge to the build-ability of the house," said the architects.

"We like to think of this project as a mutually beneficial development; the building is designed to retain the trees, while the trees visually contribute to the quality of the inner space," they added.

A raised deck runs along the northern side of the house to create an outdoor seating area beneath the canopy of the Karri, while a sheltered triangular terrace at the end of the living room features a vertical window framing another view of the tree.

A rainwater harvesting system is built into the roof, which channels water through to an irrigation system feeding the tree roots.

Plywood clads the inner and outer walls of the house. On the outside, it has a roughly sawn surface coated with a layer of black paint, while interior surfaces have been sanded smooth to reveal the natural grain.

Wooden ceiling beams were left exposed in various rooms inside the building. Straw bales were also added to provide insulation, but are concealed within the walls.

Photography is by Peter Bennetts.

Here's some more information from MORQ:

Karri Loop House

The mature trees located in the middle of the site (a Karri and two Marris) played an essential part in shaping our project. The first part of the design process was spent in investigating the requirements for retaining these trees, as well as convincing the clients of their unique presence on an otherwise anonymous site. With the support of a renowned arborist, the decision was finally made to keep the trees. As a result, the house sits in between the tree-trunks and its outline defines two open courtyards of irregular shape. These embrace the trees and the surrounding landscape, around which family life occurs.

A tall window in the dining area and a periscope-like skillion in the master bedroom, celebrate the presence of the trees from within the house, framing views of both foliage and peeling trunks. These trees, their root systems and their unstable large branches presented a challenge to the build-ability of the house. We like to think of this project as a mutually beneficial development: where the building is designed to retain the trees, while the trees visually contribute to the quality of the inner space.

To protect the integrity of the shallow root-system a matrix of steel tripod footings was used: each of them had to be dug by hand, and repositioned every time a root was encountered, resulting in an irregular structural grid. These footings also raise the house off the ground and give it a somewhat temporary look.

Any part of the house footprint overlapping the root system would result in an uneven rainwater supply to the roots, which could cause a shock to the trees. Rainwater collected on the roof is therefore taken under the house, channelled into a trickling irrigation pipes and then evenly fed to the tree roots.

Lightweight construction seemed the most appropriate response to the existing trees requirements, however straw-bales were chosen as a preferred form of insulation. This decision required all perimeter walls to be prefabricated as ladder-frames and later assembled on site. It also resulted in unusually thick perimeter walls, seldom employed in timber framed buildings.

The house was mainly constructed out of timber, whose grain and texture inform both interior and exterior spaces. Wall linings use different grades of plywood: rough sawn, painted black on the outside, and sanded, clear-treated on the inside. The floor and ceilings are also in clear-treated plywood. The roof structure is resolved with Laminated Veneer Lumber beams, which are left exposed on the inside of the ceiling.

Project typology: new house
Site: Margaret River, Western Australia
Floor area: 290 sqm
Year: 2013
Number of inhabitants: 2 adults + 3 children