Author Sean Topham says 3D printing company Icon is "really quite aggressively shaking things up." Its structures are made of "Lavacrete," a quick-drying cement-like mix, and printed using a computer-controlled nozzle that builds up layers vertically. ICON has been awarded a contract by NASA to develop a construction system for the lunar surface. "It's using what's there," says Courtenay Smith, and "a really good application for Earth ... What have we got here that we can use, rather than bringing things from the other side of the world?"
It’s an uncomfortable truth, but many of our houses are bad for the planet. They’re defined by a pattern of consumption, from the raw materials to build them, to the fuel required to sustain them, and the waste generated by them.
Despite an improvement in building energy efficiency, 2021 saw carbon emissions from building and construction hit an all-time high.
But what if a house could nurture the people living inside and the world outside too? What if a house could feed its occupants? Power itself? Boost biodiversity? Bond a community? And at the end of its life, leave no trace?
It would be ambitious to expect one house to do all that. But as demonstrated by a recently published book, many are being designed to promote a more equitable, more sustainable way of living.
Authored by Courtney Smith and Sean Topham, “Houses That Can Save the World” features over 150 projects – some concepts, the majority built – from all over the globe. Some repurpose existing spaces, such as Ensamble Studio’s off-grid cave dwelling in Menorca, Spain. Others revive and update ancient construction methods, like ZAV Architects’ adobe building community in Hormuz, Iran.
Then there are those employing cutting-edge technologies, including ICON’s 3-D printed homes, which have already been constructed in North America. In November, ICON announced it had been awarded a $57 million contract by NASA to develop a construction system for the lunar surface.
Grouped into 19 themes including “Breathe,” “Dig” and “Float,” the projects’ variety and scope is evidence there is no one-size-fits-all house for the challenges of the 21st Century.
“We found lots of people doing lots of really innovative things and doing things differently on a local level,” Topham says.
Smith says focusing on the local – from building materials to construction techniques – is a throughline of the book, and a counterpoint to prevailing attitudes in the construction industry.
The author says that 20th Century modernist design has spread, and as people have become more affluent, they have either expected or aspired to “live in concrete cleanliness.” “We forget that to construct (houses) in this kind of modernist way – that has become a global international style since the 1930s – we are destroying our planet,” she argues.
“You’re basically trying to mold the place to the material – and the result has been more detrimental than positive,” Smith adds.
The concrete and cement industry has grown tenfold over the past 65 years, steel production threefold, while low-carbon timber production per capita has experienced nearly stagnant growth, per a recent UN Environment Programme report.
The same report calculated that in 2021, the manufacturing of key building materials concrete, steel and aluminum “added a further 4% of global energy use and 6% of global emissions.”
“Houses That Can Save the World” contains plenty of examples of the good that can come from molding materials to the place.
In Mpigi, Uganda, Upcycle Africa co-founder Johnmary Kavuma lost his grandmother when her house collapsed due to flooding caused by plastic waste clogging drainage ditches, says Topham. The social enterprise now collects plastic bottles and uses them as a building material in its roundhouses, alleviating a pollution problem while providing new homes.
Despite their positive outlook, the authors acknowledge that implementing the ideas in their book can be challenging.
“As soon as you move away from (typical construction methods) it either becomes difficult to find the people to do it, it becomes incredibly expensive or it’s really time-consuming,” says Topham. “I think for your average homeowner, to do anything remotely like the examples in the book is so difficult. A lot of those barriers need to come down.”
Nevertheless, the writers are keen to practice what they preach. Smith plans to overhaul the heating at her period Texan home and fit a solar array on the roof.
The trend towards a more conscious way of building “is truly a global movement, and that in itself gives me hope,” says Smith.
CNN asked the authors to select the houses they believe could be gamechangers. To learn more about them and other projects, scroll through the gallery at the top of the page.