Australian architect John Ellway has renovated an early 20th-century cottage in Queensland into an open family home intended to encourage indoor-outdoor living.

Named Cascade House, the residence in Paddington required minimal renovations but was overhauled by Ellway to create more playful spaces for the family's three children.

It has been updated with a staggered interior arrangement defined by level changes and open spaces that aim to evoke the feeling of living in a garden.

"The stepping plan allows the living spaces to open onto grass and across the pool, creating an uninterrupted connection to the garden," Ellway told Dezeen.

"The addition creates a place to gather for conversation, meals and games."

Ellway's goal for Cascade House was to keep alterations as light-touch as possible, updating the home with improved insulation, freshly painted walls and a lean-to extension at the back that contains two bathrooms and a laundry room.

"The existing cottage received minimal intervention," said Ellway. "Really only having its floors sanded, walls painted, insulation added and electrical replaced," he continued.

"This was partly to manage cost, but mainly because its original hardwood structure and wall linings were still in great condition as they were protected from rain and sun by deep verandahs which had extended its life."

Cascade House's updated entrance leads onto a long open-plan kitchen and dining space with grey cement-coated walls. Here, a series of birch-plywood units topped with a granite worktop wrap around the end of the room and overlook an outdoor swimming pool.

Set into the lowest level of the site, this open space also features a wall of folding glass doors that allow it to open up to a tree-lined courtyard outside.

"The choice of interior finishes, particularly with the kitchen and bathroom cabinetry, ended up as a collaboration with my client and designer Jacqueline Kaytar," said Ellway. "The birch plywood was a direction she wanted to head in from the very start."

A set of concrete steps leads up to the next level of the house, where a living space fitted with a built-in corner sofa offers views over the rooms and pool nestled a metre below.

"With a four-metre level change across the site, breaking up the sequence into a series of split levels mediated this topography creating spaces to pause as you move higher," said Ellway.

"Changes in level manage privacy, with the cottage being the most private. Bedrooms within can be left messy," he explained. "There is an implied permission to be sought before a visitor is invited to continue stepping up further."

Stepped up from the living area, a porch that opens onto an L-shaped veranda connects the more communal side of the home to the private spaces. These are contained within the cottage's main volume, bordering the opposite edge of the central courtyard.

Four bedrooms branch from the hallway, each featuring white-painted timber surfaces and high ceilings that help to brighten them.

Cascade House is complete with a playroom, laundry room and a pair of bathrooms coated in white tiles at the other end of the cottage.

Other Australian houses recently featured on Dezeen include a Melbourne home that uses perforated brickwork to create private spaces and a cottage extension fully coated in Australian hardwood.

The photography is by Toby Scott.