Could a carbon-loving superculture be the answer to sustainable living?

Irish filmmaker Steve Barron began considering his contribution to the world after taking a big step. “I had turned 60 and had a new granddaughter,” he says, “that’s when I really started to focus on what I wanted to leave behind.”

Best known for directing some of the most famous music videos of the 80s, including Michael Jackson’s “Billie Jean”, and for his work on television series such as The Durrells, he felt a strong urge to do his part for the environment. When a friend mentioned hemp, the fast-growing, carbon dioxide-consuming super crop so versatile it’s being explored as a building material, Barron was converted. In 2016 he bought a smallholding in the Cambridgeshire countryside, turning over 50 acres of farmland into growing hemp (the plant can absorb 15 tonnes of CO2 per hectare). He commissioned architect Paloma Gormley of Practice Architecture to help design his house, ensuring it was built on the footprint of the old barn which she replaced with a similar aesthetic, although contemporary, which would blend into the surrounding countryside.

A factory in Leicestershire was able to strip the tough outer fibers of hemp plants, revealing their woody core, which was mixed with lime and sand to form hemp concrete poured into 8ft by 4ft panels to build the walls of the three-bedroom house. The building was then clad in a weatherproof mix of exterior plant fibers and resin, pressed into a wavy pattern to mimic the metal of the old barn. It took a year to build the Margent Farm, which was completed in 2019, when the filmmaker’s daughter and her young family moved in.

Barron is now working with researchers at the University of Cambridge to develop applications for natural fibers such as hemp, which is increasingly used in the home building industry. Hemp blocks and panels require much less energy to manufacture than materials such as concrete and they act as an excellent insulator. Margent Farm is warm in winter, cool in summer and requires minimal energy (which is provided by a mix of solar and wind power and a biomass boiler) to operate. “It’s so quiet and peaceful,” Barron said. “You feel a sense of well-being just by being there.”

Hemp home prototypes like Margent Farm are becoming increasingly popular. A few miles west of central Oxford, Knight Frank offers a five-bedroom family home built with hempcrete, paneling and bricks (and timber) for £1.6million. The home measures 3,630 square feet and was originally designed by architect John Pardey for HAB Housing, the sustainability-focused developer founded by TV presenter Kevin McCloud.

Andrés Stebelski of AS Arquitecto, based in Mexico and Europe, believes that it is impossible to see architecture “without recognizing that everything comes from nature”. As he says: “Since our beginnings, we have built using materials available around us. His design for Casa Carpinos in Mexico City puts this into practice: a family home designed as a Brutalist box over 5,000 square feet pierced with gray framed windows, it is covered in a natural clay stucco that gives the outside a soft and textured earth. -toned finish. “I like the mix of very clean lines and the fact that you can see the hand of the person who built the house in the clay,” he says.

Ancient building techniques are also used in Morocco where modern builders are increasingly returning to traditional materials such as kabash and adobe (mud bricks) as they are naturally fire resistant, energy efficient and durable. In the palm-lined oasis of the Palmeraie on the outskirts of Marrakech, the technique informs the design of the lavish mansions, where brick walls are clad in earth and lime in the style of adobe bricks (Villa A – a 9,688 sq.m. five-bedroom house, a 115ft swimming lake and views of the Atlas Mountains – is for sale at Stella Gallery, POA).

There are many different versions of Adobe around the world. Cob (a mixture of earth, water and straw, often mixed with lime) has of course been used to build houses in the UK since prehistoric times, and a new version called CobBauge, which meets the standards of contemporary thermal constructions, was developed by researchers from the University of Plymouth – the initiative quickly turned into the Anglo-French CobBauge project, as part of the European Union’s commitment to reduce CO2 emissions bringing cob construction into the mainstream. In countries with warmer climates, rammed earth (a mixture of aggregates such as gravel, sand, silt and clay pushed into formwork to create walls) is also being experimented with.

American architect Rick Joy began working with rammed earth, which dates back to the Neolithic period, after discovering it while studying at the University of Arizona and falling in love with the terracotta-hued buildings of the Sonoran Desert. “The way it captures light is so amazing – I can’t get enough of it,” he says. “Dining while smelling the earth is simply magnificent.”

The practical advantages of rammed earth construction are enormous. To find the material, says Joy, you just have to “dig a hole”, and its high thermal mass means it absorbs heat during the day and releases it at night, which is ideal for desert conditions. Visually, too, the buildings merge with their surroundings, which can be appreciated in one of Joy’s best-known adobe houses in Tucson – a 4,750 square foot house with exposed rough adobe walls topped with a roof. in weathered corrugated steel sheet. Joy built the house in three sections “to look like a train of wagons” – although it could just as well be interpreted as a spectacular rock formation. One wing houses the main living space, another the bedrooms, with a separate garage and workshop.

The appearance of cracks can be a problem in adobe houses, but Joy sees them as part of the overall charm. “I can enjoy aging gracefully,” he says. “I find perfection very boring.” He also acknowledges that this is a much bigger problem in colder countries and says the technique cannot be exported everywhere. “I constantly get calls from people in the UK asking if I can help them, and unfortunately I can’t,” says Joy. “It’s not the rain that’s the problem, it’s freezing and thawing.”

Those lucky enough to hunt for a home in Arizona will find some fine examples for sale, however, including a contemporary four-bedroom home in Paradise Valley for $12.5 million at real estate agent Engel & Völkers Scottsdale. The 6,200-square-foot Desert House (which includes a separate one-bedroom guest house) sits on 2.8 acres with views of Camelback Mountain, which is reflected in the design of its earth-toned mud walls. roses and its dramatically tilted roof. Equally striking is an adobe, steel, glass and stone home for sale near Scottsdale that offers three bedrooms on 7,412 square feet, designed around a central courtyard, and is listed for $8.995 million. with Sotheby’s International Realty.

Contemporary homes can, of course, be created from much less substantial materials – some just from pre-fabricated timber frames, straw insulation, textured cork siding and a little ingenuity. . Luca Compri of Milan-based LCA Architetti has created such an example just outside the Italian city. It took around two years to design and build his barn-style home at a cost of around £380,000, but since 2020 he’s been enjoying the benefits of cork cladding to the full – the family’s annual fuel bills are soaring around €300 per year. , compared to around €1,500 in their apartment built in the 1990s.

Compri also reminds us of the social and economic benefits of a more informed approach to home building. It highlights the use of chaff and straw once discarded by rice farmers, now being explored in sustainable construction. This creates new opportunities for them in times of globalization crisis – and a much-needed source of income.