In most Australian bushland settings the ever-present threat of bush-fires has forced Councils and other Authorities to encourage, even insist, on houses being designed and constructed to minimise the possibility of house loss due to bush-fire.

Earth Sheltered Houses meet these requirements.

ROOF SPACES

The roof space of a traditional house is dry, dusty, hot and highly flammable. Recent evidence has shown that most house loss during a bush-fire is caused by burning embers entering roof spaces through the multitude of gaps and cracks that exist between the various elements of a house. Obvious places are roof coverings, gutters and eaves linings.The arrival of burning embers can occur before, during and even well after the main fire front has passed over the house, and often the occupants are not aware for some time that the roof is alight.
Tiled roofs are notorious for ember entry and even a well built and maintained iron roof is susceptible to damage from air-born objects during a fire storm, and therefore not as safe as might be expected. A properly designed and constructed Earth Sheltered House has reinforced concrete floor, walls and roof built integral with each other and therefore offering no gaps for the ingress of embers, and effectively eliminating the “roof space” altogether.

STAY COOL

The earth covering to the roof and majority of the walls means that even during a bush-fire, the inside of the house will remain relatively cool, enhancing the ability of the occupants to act appropriately. There is no need for the occupants to be outside as the exterior of the house is non-combustible and they are safer staying inside. Every time the doors are opened increases the chances of ember entry.

SPRINKLER SYSTEMS

External sprinkler systems are often called for by the CFS as a requirement for building in a bush-fire prone area. The addition of water storage tanks and a fire fighting pump to a properly installed sprinkler system means that after the fire front has passed, any burning vegetation can be extinguished. I have adopted the use of concrete water tanks as retaining structures for the earth mounds that flank the sides of the house, thus serving two very important functions for the price of one.

WINDOW SHUTTERS

When the fire front of a bush-fire is approaching a house, possibly up the north facing slope, the wind speed can reach cyclonic proportions. In this situation the windows are vulnerable. The use of toughened glass set in aluminium frames is a minimum standard and the integration of roller shutters into the overall design is recommended. Shutters not only protect the window glass from damage, but also provide thermal comfort and security throughout the year. There are models available that have battery back-up, and will lower themselves when activated by high temperatures or smoke, so they will operate even if you are not there.