Earth-sheltered homes: a limited and costly solution for high-risk bushfire zones Alternative housing solutions for bushfire-prone areas raise concerns and costs

With an increasing frequency of extreme fire conditions across larger regions of Australia, we must explore alternative options for living in high-risk bushfire areas. One such option is underground or earth-sheltered housing, which is gaining popularity in these regions.

However, before we embrace this type of housing as a widespread solution, we must consider its complexities. Factors such as design and construction challenges, cost, and occupants' behavior must be carefully weighed. Moreover, there is limited real-world evidence of how these homes perform during bushfires.

A broader question is whether we should allow more people to live in bushfire-prone areas at all. Doing so could lead to more deaths and injuries.

Earth-sheltered homes are often integrated into slopes, but they can also be built on flat ground by excavating or covering the building with earth. In Australia, concrete is typically used for the building structure to support the weight of the soil covering the roof and walls. These earth-covered areas can also be planted with vegetation.

Due to the large amount of earth in contact with the exterior, special attention must be paid to ensure the building is watertight and structurally sound.

These homes typically have one main wall of windows facing away from the earth-covered side to allow for natural light. Building regulations require the inclusion of rear windows in light wells or vents for proper ventilation.

One advantage of earth-sheltered homes is their ability to maintain a stable internal temperature. They also use significantly less energy for heating and cooling, up to 84% and 48% respectively, compared to buildings with black roofs. Additionally, these homes offer opportunities for improved aesthetics, landscaping, gardens, and recreation, offsetting the limited windows and building constraints.

However, bushfires present complex risks, and earth-sheltered homes may only be a useful but expensive and limited solution in areas with existing housing. Since there is a lack of evidence on their performance during fires, they may not be the most effective solution in these areas.

Furthermore, the cost of implementing bushfire-resistant measures such as heat and flame-resistant windows can significantly increase the cost of construction, estimated at $53,000 to $273,000 compared to a typical home.

The orientation of these homes can also pose a challenge, as the window side is often facing downhill, making it more susceptible to intense bushfire attacks. In some cases, this may require the removal of natural vegetation, which can have negative ecological impacts and increase the risk of landslides.

While it is possible to engineer a home that can withstand bushfires, human factors such as poor maintenance, unsafe storage of flammable items, and modifications to the property can increase the risk of destruction. Despite education campaigns, people continue to put themselves in dangerous situations before and during bushfires, increasing the likelihood of injury and death for both residents and responders.

The psychological effects of extreme fires on those affected are significant, with almost three-quarters of individuals experiencing anxiety for up to two years after the 2019-2020 Black Summer bushfires. Even if a structure survives, the isolation, loss of communication, and intense conditions of extreme fires can have a profound impact on individuals.

Therefore, it is crucial to consider people's varying levels of awareness and ability to assess bushfire risk. It is unwise to increase the population in bushfire-prone areas that will only become riskier over time. Instead, we should explore a range of solutions, such as earth-sheltered homes, to reduce risks in existing residential areas. However, at a larger scale, building low-density housing in these areas conflicts with the need for higher-density housing in established areas to accommodate Australia's growing population. Higher-density housing would provide better access to services, infrastructure, jobs, and public transport.

In conclusion, while earth-sheltered housing may be a viable option for some in bushfire-prone areas, it is not a widespread solution. We must carefully consider the complexities and limitations of this type of housing and explore other solutions that prioritize safety, sustainability, and long-term planning.

David Lamy
David Lamy Author
David Lamy owns the Bachelor in Atmospheric Science Degree. He is associated with Industry News USA from last 2 years. With proficiency in his work, David obtained a strong position at Industry News USA and heads the Science section. “Weather forecasting” is the field of his interest. He bags total 5 years of experience in this field. Apart from his routine work, David loves to explore his cooking skills. He has participated in various cookery shows.