This couple turned glass bottles into a home in Melbourne. Here's how Earthship houses work

After repeatedly losing out in Melbourne's property market, an Australian couple bought land in Tasmania and built their own unusual home using recycled glass bottles, rammed earth and passive-solar design.

In Short

• Matt Ellis and Kate Tucker built their Earthship near Cygnet, Tasmania
• The home uses recycled glass bottles, rammed earth and passive-solar principles
• So, what exactly is an Earthship, and how does it work?

Australian couple Matt Ellis and Kate Tucker wanted a home of their own but repeatedly found themselves priced out of Melbourne's property market. After losing out to higher bidders several times, they eventually decided to take a different route: buy land and build their own home.

They purchased 1.5 hectares near Cygnet in Tasmania and began building a house inspired by the Earthship movement. The unusual home combines recycled materials with design techniques intended to make a house more energy and resource efficient.

The project took nearly three years to complete. The couple had initially expected to spend around A$600,000, but the final cost reached about A$880,000.

WHAT IS AN EARTHSHIP?

An Earthship is a type of building designed around the idea of using recycled or natural materials and passive systems to make a home more self-sufficient.

The concept was developed by American architect Michael Reynolds in New Mexico in the 1970s. Earthships typically incorporate features such as thermal-mass walls, passive solar heating, rainwater collection, renewable energy and systems designed to reduce dependence on conventional utilities.

Importantly, not every Earthship looks the same. The basic principles can be adapted to different climates, sites and architectural styles.

WHY ARE OLD BOTTLES USED IN THE WALLS?

One of the most striking features of the Tasmania house is its glass-bottle walls.

Recycled bottles can be incorporated into walls as bottle bricks, particularly for internal partitions, feature walls and greenhouse or sunroom areas. When sunlight passes through the coloured glass, it can create patterns of light inside the house.

But the bottles are not what makes the main structure strong. Bottle walls are generally non-load-bearing; the surrounding mortar or cob provides their stability. Structural support comes from conventional or engineered elements elsewhere in the building.

WHAT ELSE IS DIFFERENT ABOUT THIS HOUSE?

The couple also used rammed earth, which can act as thermal mass. Such thick earthen walls can absorb heat and release it gradually, helping moderate indoor temperatures.

The house also uses passive solar design, with its orientation and windows designed to make better use of natural sunlight. A greenhouse is another part of the design.

DID THE BOTTLES MAKE THE HOUSE CHEAPER?

Not necessarily.

Although using discarded materials sounds like an obvious way to reduce construction costs, this project ended up costing considerably more than the couple's original estimate. Construction difficulties, delays and other complications pushed the final bill to around A$880,000.

That is an important part of understanding Earthships: using recycled materials does not automatically mean building a cheap house. The concept is more about changing how a building uses materials, energy, water and its surrounding environment.

WHY IS THE EARTHSHIP IDEA DIFFERENT FROM A NORMAL ECO-FRIENDLY HOUSE?

The key difference is that an Earthship tries to combine several systems within the house itself, from thermal mass and passive solar heating to water management, renewable energy and, in some designs, food production.

In other words, it is not simply a house with recycled materials. The larger idea is to design the building itself as part of the resource system.

- Ends