What are Earthships and how can they help with bushfire rebuilding?

What are Earthships and how can they help with bushfire rebuilding?
Staff reporterMarch 8, 2020

GUEST OBSERVATION

Recent disastrous bushfires have rebooted debate about how to (re)build in the Australian bush. Questions are being asked about building standards, whether a fire-proof home is possible, the value of fire bunkers when it’s too late to leave, and if we should even live in the bush any more.

I suggest homes and community buildings in bushfire-prone areas can be made much more fire-resistant, perhaps even fire-proof, by adopting earth-covered, off-grid structures – known as Earthships – as the new standard.

Built for survival

Houses sheltered by earth have a higher chance of survival in a bushfire. This is because earth-based constructions are non-flammable (while topsoil can burn and smoulder, clayey, sandy and gravelly soil does not).

A typical Earthship design has double-glazed windows to the north to let in winter sun, while mounds of earth, pushed up to roof level, protect the south, east and west walls. Taking this a step further, an earth-covered house includes a layer of earth over the roof.

The north-facing double-glazed windows (an essential element of passive solar design) is the only part of the building that needs some other protection.

Bushfire building codes and standards already demand that windows have extra-thick, toughened glass to resist burning debris and intense heat. Double glazing (two layers of glass separated by a small air gap) offers extra protection. In very high-risk areas, bushfire shutters are a requirement.

Although not demanded by building codes, automated sprinklers could be used to spray water on the windows. But automated systems are problematic during a bushfire when power and water supplies are likely to fail.

Independent water supplies (big water tanks) and pumps (usually petrol or diesel) are often a condition of approval for new homes in fire-prone areas. However, these are difficult to automate because of choke, throttle, ignition and refuelling issues.

Examples around Australia

Enter the Earthship. Invented by American architect Michael Reynolds, thousands have been built all over the world, often by owner-builders.

I built Australia’s first council-approved Earthship – Earthship Ironbank - in the bushfire-prone Adelaide hills. Australian examples can be found in all states, including at Ironbank in South Australia, Kinglake in Victoria, East Augusta and Jurien Bay in Western Australia, and Narara and Marulan in New South Wales.

Earthships have an electric pump powered by solar panels and a battery for day-to-day water supply – and to fight fires. Sprinklers can then spray water on any vulnerable areas regardless of grid failures and without needing to deal with the flammable fuel that petrol and diesel pumps require.

The standard Earthship design has another feature that could save lives. Underground pipes called earth-tubes or cooling tubes bring fresh air into the building at a nice temperature (better than outside) due to the heat-exchanging effect of the earth around the pipes. When wet fabric is placed over the end of the pipes, these can filter out bushfire smoke.

Earth-covered homes are very air-tight, which combined with the earth-tubes helps keep out smoke and reduce asphyxiation risks.

Another defence mechanism is the “greenhouse”, a sunroom and corridor space on the sunny north side used for passive heating and cooling, treating wastewater and growing food. Yet another layer of double glazing isolates the greenhouse from the living spaces behind it. Adding indoor sprinklers (commonplace in commercial buildings) to the greenhouse could create a “wet buffer zone” and stop embers blowing into living areas where flammable furnishings are a hazard.

An iconic Earthship feature is the tyres used to form the exterior earth walls. While empty tyres are highly flammable, in this design they are not. The tyres are filled with compacted earth and protected by a layer of earth many metres thick (inside walls are rendered). There is already evidence of their fire-resistant nature.

Safer for the planet too

My PhD research focused on the energy efficiency and environmental footprint of the Earthship, comparing it to other construction systems and designs.

Earth is a low-cost, readily available material. It takes very little energy to dig it up, needs no processing and minimal (if any) transport. It is difficult to think of a more sustainable, inexpensive and non-flammable material.

I found off-grid homes minimise their eco-footprint by kicking three very dirty habits: the power, water and sewage grids. “Earthy” construction methods, such as Earthship, rammed earth, mudbrick and strawbale, also have much lower environmental impacts.

Earth-covered buildings are renowned for their energy efficiency. Earth insulates and has “thermal mass”, an architectural term for dense materials (e.g. concrete, brick, rammed earth, water). Thermal mass evens out temperature changes by absorbing heat when it is too hot inside and releasing heat when it is too cold inside. This means minimal heating and cooling bills.

There are a few “tricks” to getting council approval. Hire an experienced structural engineer and use a private certifier or surveyor for building rules consent as they are better equipped to certify compliance with the National Construction Code. The one aspect of the Earthship I couldn’t get approved was an indoor greywater garden and toilet-flushing system.

Parts of the roof are earth-covered with fire-fighting sprinklers on the roof and windows. If I was building again I’d prioritise bushfire resilience by making it fully earth-covered with fire shutters, sprinklers and a safe room.

Further study is needed to scientifically validate my proposal here. However, we already have some evidence that Earthships, with a few minor design changes, might be the most sustainable, liveable, economical, fire-resistant buildings ever conceived of.The Conversation

Martin Freney, Lecturer in Industrial and Sustainable Design, University of South Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Editor's Picks

Spyre Group brings successful Queensland blueprint to Melbourne with Hampton Ltd
Saxon Street by Milieu to bring new housing and urban design to Brunswick’s cultural core
Construction begins at Fishermans Bend Innovation Precinct
Gurner reveals new plans for final Jam Factory stage
Tian An launches North Village, Auburn Square second stage

Related Projects

16-22 Maud Street, Newstead QLD 4006
16-22 Maud Street, Newstead QLD 4006
16-22 Maud Street, Newstead QLD 4006
Price
Contact agent
35-37 Mount Street, Prahran VIC 3181
35-37 Mount Street, Prahran VIC 3181
35-37 Mount Street, Prahran VIC 3181
Price
Contact agent
118-124 Benelong Road, Cremorne NSW 2090
118-124 Benelong Road, Cremorne NSW 2090
118-124 Benelong Road, Cremorne NSW 2090
Price
Contact agent
118-120 Matthew Flinders Drive, Cooee Bay QLD 4703
118-120 Matthew Flinders Drive, Cooee Bay QLD 4703
118-120 Matthew Flinders Drive, Cooee Bay QLD 4703
Price
Contact agent
26-62 Kinross Road, Thornlands QLD 4164
26-62 Kinross Road, Thornlands QLD 4164
26-62 Kinross Road, Thornlands QLD 4164
Price
Contact agent
9-11 Baroonba Street, Whitebridge NSW 2290
9-11 Baroonba Street, Whitebridge NSW 2290
9-11 Baroonba Street, Whitebridge NSW 2290
Price
Contact agent
18 Ransley Street, Penrith NSW 2750
Perle, East Side Quarter, Penrith - 18 Ransley Street, Penrith
18 Ransley Street, Penrith NSW 2750
Price
Contact agent
Ernest Cavanagh Street, Gungahlin ACT 2912
Raya, Gungahlin - Ernest Cavanagh Street, Gungahlin
Ernest Cavanagh Street, Gungahlin ACT 2912
Price
Contact agent
39 Browning Street, South Brisbane QLD 4101
39-41 Browning Street, South Brisbane - 39 Browning Street, South Brisbane
39 Browning Street, South Brisbane QLD 4101
Price
Contact agent
675 Gardeners Road, Mascot NSW 2020
Kiara North, Mascot - 675 Gardeners Road, Mascot
675 Gardeners Road, Mascot NSW 2020
Price
Contact agent
187 Salvado Road, Jolimont WA 6014
Jolie, Jolimont - 187 Salvado Road, Jolimont
187 Salvado Road, Jolimont WA 6014
Price
Contact agent
47 Maning Avenue, Sandy Bay TAS 7005
Grace Residences - 47 Maning Avenue, Sandy Bay
47 Maning Avenue, Sandy Bay TAS 7005
Price
Contact agent
Cove Lane, Narooma NSW 2546
Cove, Narooma - Cove Lane, Narooma
Cove Lane, Narooma NSW 2546
Price
Contact agent
52-56 Ramsay Street, Five Dock NSW 2046
Ava, Five Dock - 52-56 Ramsay Street, Five Dock
52-56 Ramsay Street, Five Dock NSW 2046
Price
Contact agent
2375 Gold Coast Highway, Mermaid Beach QLD 4218
The Alfred - 2375 Gold Coast Highway, Mermaid Beach
2375 Gold Coast Highway, Mermaid Beach QLD 4218
Price
Contact agent
129-131 Russell Ave, Dolls Point NSW 2219
ALLURE COLLECTION - 129-131 Russell Ave, Dolls Point
129-131 Russell Ave, Dolls Point NSW 2219
Price
Contact agent
62 Constitution Avenue, Parkes ACT 2600
The Eastbourne on Commonwealth Park - 62 Constitution Avenue, Parkes
62 Constitution Avenue, Parkes ACT 2600
Price
Contact agent
155 Old Burleigh Road, Broadbeach QLD 4218
Sandpiper, Broadbeach - 155 Old Burleigh Road, Broadbeach
155 Old Burleigh Road, Broadbeach QLD 4218
Price
Contact agent
33 Vulture Street, West End QLD 4101
33 Vulture Street, West End QLD 4101
33 Vulture Street, West End QLD 4101
Price
Contact agent
19 Governor Terrace, Murarrie QLD 4172
Park Hill Village Collection, Murarrie - 19 Governor Terrace, Murarrie
19 Governor Terrace, Murarrie QLD 4172
Price
Contact agent
122 Marine Parade, Miami QLD 4220
Nalu, Miami - 122 Marine Parade, Miami
122 Marine Parade, Miami QLD 4220
Price
Contact agent
34 Jacaranda Place, Indooroopilly QLD 4068
34 Jacaranda Place, Indooroopilly QLD 4068
34 Jacaranda Place, Indooroopilly QLD 4068
Price
Contact agent
167 Old Burleigh Road, Broadbeach QLD 4218
167 Old Burleigh Road, Broadbeach QLD 4218
167 Old Burleigh Road, Broadbeach QLD 4218
Price
Contact agent
21 Queens Way, Yeerongpilly QLD 4105
Yeerongpilly Green - 21 Queens Way, Yeerongpilly
21 Queens Way, Yeerongpilly QLD 4105
Price
Contact agent
445-449 River St, Ballina NSW 2478
Solhaven - 445-449 River St, Ballina
445-449 River St, Ballina NSW 2478
Price
Contact agent
52 Sunset Boulevard, Surfers Paradise QLD 4217
52 Sunset Boulevard, Surfers Paradise QLD 4217
52 Sunset Boulevard, Surfers Paradise QLD 4217
Price
Contact agent
6 Jack Brabham Drive, Hurstville NSW
Horizon Hurstville - 6 Jack Brabham Drive, Hurstville
6 Jack Brabham Drive, Hurstville NSW
Price
Contact agent
49 Seena Drive, Edgeworth NSW 2285
49 Seena Drive, Edgeworth NSW 2285
49 Seena Drive, Edgeworth NSW 2285
Price
Contact agent
Lot 118 Ocean Steamers Road, Port Adelaide SA 5015
Lot 118 Ocean Steamers Road, Port Adelaide SA 5015
Lot 118 Ocean Steamers Road, Port Adelaide SA 5015
Price
Contact agent
203 Ashmore Road, Benowa QLD 4217
203 Ashmore Road, Benowa QLD 4217
203 Ashmore Road, Benowa QLD 4217
Price
Contact agent
41 Warrs Road & 7 Horizon Drive, Maribyrnong VIC 3032
41 Warrs Road & 7 Horizon Drive, Maribyrnong VIC 3032
41 Warrs Road & 7 Horizon Drive, Maribyrnong VIC 3032
Price
Contact agent
774 Ripley Road, Ripley QLD 4306
774 Ripley Road, Ripley QLD 4306
774 Ripley Road, Ripley QLD 4306
Price
Contact agent
6 Homelea Court, Rivervale WA 6103
6 Homelea Court, Rivervale WA 6103
6 Homelea Court, Rivervale WA 6103
Price
Contact agent
7002 Ripley Road, Ripley QLD 4306
7002 Ripley Road, Ripley QLD 4306
7002 Ripley Road, Ripley QLD 4306
Price
Contact agent
136-148 Fox Valley Road, Wahroonga NSW 2076
136-148 Fox Valley Road, Wahroonga NSW 2076
136-148 Fox Valley Road, Wahroonga NSW 2076
Price
Contact agent
3 Delos Way, Sorrento WA 6020
3 Delos Way, Sorrento WA 6020
3 Delos Way, Sorrento WA 6020
Price
Contact agent
77 Sutton Street, Redcliffe QLD 4020
77 Sutton Street, Redcliffe QLD 4020
77 Sutton Street, Redcliffe QLD 4020
Price
Contact agent
119 Queen Street & 86 King Street, Bendigo VIC 3550
119 Queen Street & 86 King Street, Bendigo VIC 3550
119 Queen Street & 86 King Street, Bendigo VIC 3550
Price
Contact agent
181 Prospect Road, Prospect SA 5082
181 Prospect Road, Prospect SA 5082
181 Prospect Road, Prospect SA 5082
Price
Contact agent
593-595 Albany Highway, Victoria Park WA 6100
593-595 Albany Highway, Victoria Park WA 6100
593-595 Albany Highway, Victoria Park WA 6100
Price
Contact agent
1-28, 40 Civic Way, Rouse Hill NSW 2155
1-28, 40 Civic Way, Rouse Hill NSW 2155
1-28, 40 Civic Way, Rouse Hill NSW 2155
Price
Contact agent
93-97 Bay Street, Brighton VIC 3186
93-97 Bay Street, Brighton VIC 3186
93-97 Bay Street, Brighton VIC 3186
Price
Contact agent
22-38 & 27-31 The Avenue, Coburg VIC 3058
22-38 & 27-31 The Avenue, Coburg VIC 3058
22-38 & 27-31 The Avenue, Coburg VIC 3058
Price
Contact agent
1F Ashline Street, Wollert VIC 3750
1F Ashline Street, Wollert VIC 3750
1F Ashline Street, Wollert VIC 3750
Price
Contact agent
Lots 100 & 900 Kentucky Court, Cockburn Central WA 6164
Lots 100 & 900 Kentucky Court, Cockburn Central WA 6164
Lots 100 & 900 Kentucky Court, Cockburn Central WA 6164
Price
Contact agent
1260-1272 Malvern Road, Malvern VIC 3144
1260-1272 Malvern Road, Malvern VIC 3144
1260-1272 Malvern Road, Malvern VIC 3144
Price
Contact agent
472 Regency Road, Prospect SA 5082
472 Regency Road, Prospect SA 5082
472 Regency Road, Prospect SA 5082
Price
Contact agent
273A Gorge Road, Paradise SA 5075
273 Gorge Road, Paradise SA 5075 - 273A Gorge Road, Paradise
273A Gorge Road, Paradise SA 5075
Price
Contact agent
426-440 New South Head Road, Double Bay NSW 2028
426-440 New South Head Road, Double Bay NSW 2028
426-440 New South Head Road, Double Bay NSW 2028
Price
Contact agent
270 The Esplanade, Miami QLD 4220
270 The Esplanade, Miami QLD 4220
270 The Esplanade, Miami QLD 4220
Price
Contact agent