North Arrow Studio has completed a compact, corrugated metal accessory dwelling unit in East Austin's Chestnut neighbourhood featuring a custom, circular pivot window that is reminiscent of the round opening in a birdhouse.

Aptly named the Birdhouse, the 900-square foot (84-square metre) ADU shares a narrow 5,900-square metre (550-square metre) lot with a 1939 single-storey house and three large protected pecan trees.

North Arrow Studio's principal architect Francisco Arredondo described the two-bedroom, two-bath house as "simplicity carried to the extreme".

"There's simplicity in the footprint, the massing, and the material palette throughout," Arredondo said. "But it's also a smart little house that makes me smile."

The home was strategically placed around the trees to create a courtyard between the main house and the ADU while providing privacy for the separate living quarters.

The L-shaped plan features a bedroom, bathroom, kitchen and living room featuring a roll-up garage door on the ground floor, all wrapped around an external pecan tree.

Upstairs, the main suite sits within the vaulted ceiling of the double-gabled form. Four five-foot (1.5-metre) diameter circle windows sit under each gable and use the surrounding tree canopy for privacy.

"They create a resemblance to a traditional birdhouse and bring a sense of whimsy to the design," the studio said.

One of the custom-fabricated steel windows serves as the required egress for the room.

"We began with a pivot design and worked our way towards a final swing design that opened up to the pecan tree's canopy," the team explained.

The rounded-window motif carries throughout the house with miniature custom steel circle windows.

"Strategically selected walls are curved to soften edges and draw you into the spaces," the studio said. "Interior finishes are simple and restrained apart from a few accent walls that give life to each room."

The monotone ADU is wrapped in light corrugated metal that "is a nod to the many metal sheds and accessory buildings already found throughout the neighborhood, but with a modern and playful twist".

The soft, rounded edges and neutral colour complement the existing house and provide an accent along the alley, and the metal runs up the walls and becomes the roof material as well.

In the courtyard, a curved polycarbonate wall brings light into the hallway and creates a softly glowing, semi-transparent effect.

Corrugated metal was selected for its sustainability and resilience as the envelope is 100 per cent recyclable, repels sun and heat in Texas summers and is durable and low-maintenance, according to the studio.

"Working with a tight budget and constrained footprint can be very helpful in creating a story for the design," the studio said. "The constraints begin to guide you and lend opportunities to be creative with traditional materials and spaces in ways that typically wouldn't be considered."

In 2014, North Arrow Studio created a stilted home in the Texas Hill Country that references Mies Van der Rohe's glass Farnsworth House.

The photography is by Chase Daniel.

Project credits:

Builder, developer, owner: Brita Wallace, Digs ATX
Styling: Ben Newman Studios