ICON + BIG-Bjarke Ingels Group
Around the world, innovative homes are redefining how we live. A new book, "Houses That Can Save the World," collects more than 150 examples. Scroll through the gallery to learn more about them.

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?"
Courtesy Thames & Hudson
Plugin Houses, China, People's Architecture Office (2016-2018) -- In the dense hodgepodge of some of the old urban neighborhoods in Beijing and Shenzhen, houses are being updated with new sections that can be slotted into or around existing and dilapidated structures. The prefabricated panels can be carried through narrow streets, explains Topham, giving a new lease of life to buildings that might otherwise be bulldozed, and keeping families in communities they have lived in for generations.
courtesy Thames & Hudson
Buoyant Ecologies Floating Lab, Oakland, California, Architectural Ecologies Lab (2019) -- It may not look like home, but this prototype building is providing insights into the future of marine living. The polymer structure acts as a breakwater to reduce coastal erosion, while its curved and ridged shape is designed to collect rainwater above the surface and provide a habitat for ocean invertebrates on its underside. "I think this is one of my favorite projects in the book," says Topham, who says the concept is being tested further in the Maldives, where it could find application bolstering the islands' shoreline, and also capturing nutrients for mangroves.

courtesy Thames & Hudson
Villa Vals, Vals, Switzerland, SeARCH and Christian Müller Architects (2009) -- This cave-like home cut into a Swiss hillside is accessed via an underground tunnel beginning in a nearby barn. Its circular facade allows an abundance of light into the property while having a low impact on the landscape. "What I found so fascinating about it is this idea that links us back to our primeval selves: I need shelter, how do I attain it? Well, I dig myself in," says Smith. "When I spoke to (architect) Christian Müller he said (his) intention was to let nature take the lead. And I found that not only poetic, but also it's a great way of thinking about resources."
courtesy Thames & Hudson
Flat House, Cambridgeshire, UK, Practice Architecture (2019) -- The client for this English project makes hemp-based products, and wanted to build using hemp grown on site. Hemp was processed into prefabricated hempcrete blocks, which don't have structural properties, says Topham, but are good at heat insulation and moisture control. The blocks were slotted into a timber frame and the building covered with cladding made from hemp fiber and a sugar-based resin. Hempcrete is biodegradable, so in theory, "once (it's) finished with it can be dismantled, and the material used can be put back into the land," says Topham.
Courtesy Thames & Hudson
House for Trees, Ho Chi Minh, Vietnam, Vo Trong Nghia Architects (2014) -- Designed to fit into the dense urban living of Vietnam's largest city, these homes have turned their deep flat roofs into giant containers for flora. "I just love this idea of having a house that is essentially like a massive plant pot," says Topham. Their composition creates internal courtyards, while the green roofs acts as a filter for the city's aerial pollutants. "The planting has to come first," he adds, "rather than doing it as an afterthought."
courtesy Thames & Hudson
Mud Shell prototype, London, UK, MuDD Architects (2018) -- The European architecture firm put on a show at the London Design Festival with a simple, quick-to-build structure with a high-tech twist: it was completed by a drone operating a hose covering it in sprayable clay. The delivery method has the potential to find other uses. Architect Stephanie Chaltiel has trialed drones that can carry 220lbs of biomaterial than could be used to treat hard-to-access facades, potentially replacing the need for scaffolding.
courtesy Thames & Hudson
Jintai Village Reconstruction, Bazhong, China, Rural Urban Framework (2017) -- Homes in the village had been destroyed by an earthquake in 2008 and then a landslide in 2011. Rural Urban Framework collaborated with the government and non-profits on a replacement 22-house community with many elements to promote self-sufficiency, including garden roofs, water collection, a biogas generator and reedbed waste treatment system. The ground floor level is entirely communal. "All of these homes move away from the idea of consumption to circular architecture," says Smith. "They're a good example of how you can go back to an understanding of yourself and your community as an autonomous system."
courtesy Thames & Hudson
Casa Covida, San Luis Valley, Colorado, Emerging Objects (2020) -- A 3D printed house built from adobe, in keeping with the area's vernacular. The wood used in the building is from trees damaged by mountain pine beetle. An inflatable roof protects residents from inclement weather and traps heat.
courtesy Thames & Hudson
Building with Earth, Macha, China, Professor Mu Jun and Bridge to China (ongoing) -- A collaboration between academics at the Beijing University of Civil Engineering and Architecture and a charitable organization, is reintroducing ancient building techniques in rural China. In Macha, Professor Mu and a team of students and craftspeople are educating residents in how to construct and maintain their houses from rammed earth. The buildings are cooler in the summer, warmer in the winter and cheaper to build than typical houses, according to the project. The skills residents are learning can also offer a potential income. "It's this incremental model," says Smith, "that begins to expand outwards as people begin to take their knowledge back into their own hands."
courtesy Thames & Hudson
A Guy, a Bulldog, a Vegetable Garden and the Home They Share, Madrid, Spain, Husos Arquitecturas (2018) -- This doctor's apartment conversion was tailored to the needs of his demanding shift work, and his dog. The space was opened up, introducing more light and cooler temperatures, and nooks and surfaces made multifunctional. Graywater from the shower is collected and used in the balcony garden.
courtesy Thames & Hudson
Presence in Hormuz 2, Hormuz, Iran, ZAV Architects (2020) -- These colorful buildings are crafted using the SuperAdobe system by non-profit CalEarth. The method for building these domed structures was pioneered by renowned architect Nader Khalili. Sandbags are filled with moist earth, which are arranged in coils and reinforced with barbed wire and sometimes cement, lime or asphalt between layers. The outside is finished with plaster, protecting the structure from erosion. In Hormuz, 200 buildings were made this way to create a holiday village.
CNN  — 

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.

Courtesy Thames & Hudson
A 2020 ZAV Architects project, Presence in Hormuz 2, in Hormuz, Iran, used a technique called SuperAdobe to construct 200 buildings. Sandbags are filled with moist earth, which are arranged in coils and reinforced with barbed wire and sometimes cement, lime or asphalt between layers. The outside is finished with plaster, protecting the structure from erosion.

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.”

Courtesy Thames & Hudson
Villa Vals in Switzerland, a home built into a hillside and accessed via a tunnel from a nearby barn.

“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.