The US produces millions of tonnes of rice waste each year. Now people are building homes with it

HomeNewsUS & CanadaUKUK PoliticsEnglandN. IrelandN. Ireland PoliticsScotlandScotland PoliticsWalesWales PoliticsAfricaAsiaChinaIndiaAustraliaEuropeLatin AmericaMiddle EastIn PicturesBBC InDepthBBC VerifySportBusinessWorld of BusinessTechnology of BusinessNYSE Opening BellTechnologyWatch DocumentariesArtificial IntelligenceIntelligence RevolutionAI v the MindTech NowHealthWatch DocumentariesCultureWatch DocumentariesFilm & TVMusicArt & DesignStyleBooksEntertainment NewsArtsWatch DocumentariesArts in MotionTravelWatch DocumentariesDestinationsAfricaAntarcticaAsiaAustralia and PacificCaribbean & BermudaCentral AmericaEuropeMiddle EastNorth AmericaSouth AmericaWorld’s TableCulture & ExperiencesAdventuresThe SpeciaListTo the Ends of the Earth EarthWatch DocumentariesScienceNatural WondersClimate SolutionsSustainable BusinessGreen LivingAudioPodcast CategoriesRadioAudio FAQsVideoWatch DocumentariesBBC MaestroDiscover the WorldLiveLive NewsLive SportDocumentariesSite searchHomeNewsSportBusinessTechnologyHealthCultureArtsTravelEarthAudioVideoLiveDocumentariesWeatherNewslettersThe US produces millions of tonnes of rice waste each year. Now people are building homes with it9 minutes agoShareSaveAdd as preferred on GoogleNick AspinwallModern MillThe recently completed Palisades properties in California are among the new US homes using rice husk panelling (Credit: Modern Mill)A notoriously stubborn agricultural waste product, rice husk is now being repurposed as a sturdy and resilient construction material.

In 2023, David Fine had a problem. He had been hired to renovate a luxury ski condo development in Park City, Utah, in the US. But the building requirements were proving challenging.

The existing condos had begun to rot under the town's famous powdery snow, which piles up for months during the long winters. The homeowner's association had spent a year searching for a material that would absorb moisture while also resisting the increasingly frequent wildfires that threaten the mountaintop locale in summer.

They considered products like extruded aluminium, which would protect the condos against fire but appear synthetic. Wooden sidings such as cedar, on the other hand, would achieve a more pleasing aesthetic, but with a weaker fire rating.

Finally, they came up with an outlandish-sounding solution: panel boards made from rice husks – a byproduct of rice farming. "Their focus was to find something that looked like wood, that was beautiful, and that was a little better fire-rated than traditional wood siding," Fine says. Rice husk panels, it turned out, "checked all those boxes".

Previously viewed as a waste product and even pollutant, rice husks are now attracting attention for their potential as a versatile, sustainable construction material. With hundreds of new homes in the US now using rice husk panelling, and other rice husk products from porches to playgrounds available, why are some developers choosing this agricultural throwaway over classic materials?

While growing on the plant, rice husks protect the grains from moisture and pests. But when the crop is harvested, they become one of the most stubborn agricultural waste products to deal with.

The world produces around 150 million tonnes (331 billion lb) of rice husk each year, much of it burned on farms or at roadsides, posing risks to both human health and the environment. In the US, which grows some nine million tonnes (20 billion lb) of rice annually, rice husk is sometimes converted into biomass energy, though even then there's not always a clear use for the ash left behind.

A pioneering solution kills two birds with one stone – repurposing this agricultural waste as a durable and sustainable building material of the future.

Alongside the use of materials made from rice husks in panelling and other construction materials, research suggests rice husk ash could provide an alternative to cement, which is responsible for 8% of global carbon emissions.

Christopher Guimond first became curious about rice byproducts when he discovered US rice producers let the waste decompose in the ground and release polluting clouds of methane, a potent greenhouse gas. An engineering student, Guimond started to believe that rice husks would make the perfect material to use at scale in construction.

"The fascination was to take this thing that was a throwaway and leverage its properties," he says.

Guimond is now the chief executive of Modern Mill, the first US-based company that manufactures construction products out of rice husks at scale. Since it was founded in 2018, the company says it has diverted over nine million kg (20.5 million lb) of rice husks from landfill, including as the panelling for Fine's ski condos.

It is often easier to adopt a new floor tile material than it is to adopt a new material for a beam – Sabbie MillerAround the world, other companies including Resysta in Germany and design firm Ricehouse in Italy are producing or using all kinds of construction materials, from decking to paint, made from rice husks. Modern Mill is even using it to make playgrounds.

Rice husks protect the precious grains from wind and rain, and their high silica content allows them to resist moisture and decay, meaning they naturally boast the same properties as many traditional construction materials. "The whole point of the rice husk is to protect the rice while it grows," Guimond says. "What is it protecting it from? Moisture, pests, rot, those types of things."

In addition to protecting against moisture, the high silica content means rice husks are surprisingly resilient to fire, according to Fine. Modern Mill's product is designated as Wildland Urban Interface (WUI) compliant, meaning it has passed California's fire safety testing.

Timber has long been considered a sustainable building material. It is abundant in continental climates and has comparatively low carbon emissions compared to materials like concrete and steel.

But it can also have environmental and financial downsides, from vulnerability to price shocks to the depletion of old growth forests and the carbon they store and absorb.

Rice isn't the only unusual alternative building material being tested out. In the Global South, bamboo is increasingly being used as an alternative to concrete and more expensive, slower-growing tropical hardwoods. But the wide availability and low cost of rice husk, added to the fact it is a waste material, gives it a distinct advantage.

A recent study found that using the fibrous residues from crops like rice, wheat and maize for buildings, rather than burning them, could produce a significant carbon sink, since the carbon caught in these residues would be locked away for decades.

Sabbie Miller, an expert in sustainable building materials and professor in civil and environmental engineering at the University of California, Davis, notes however that whether or not a particular building material will be low-carbon can be very nuanced and requires a detailed life cycle assessment.

Research has found that rice husk panels perform as well as traditional materials when it comes to thermal and acoustic control. In Italy, for example, rice panels were used within Casa LH, a project recently completed by Ricehouse, to control its acoustics and thermal performance.

The house, designed to rebuild a previous structure, features large south-facing windows and an open kitchen that brings sunlight and air but also seasonal heat and echoes. "We had to add another way to insulate more and guarantee acoustic comfort," says Valentina Savioli, a communications officer at Ricehouse. Using rice as insulation was an easy decision "just because of how much volume and biomass [it] has", she adds.

However, more widespread adoption might prove tricky since Italian contractors are generally sceptical of less common building materials, says Savioli.

There can be similar concerns in the US, as well as barriers like cost, says Miller.

"There can be hesitancy to use materials if, for example, an engineer could compromise their license or ability to get hired if there is a material failure," she says.

However, adoption of non-load bearing rice husk products (the case for Modern Mill's panels) will likely face fewer challenges than using them in load bearing materials, she adds. "It is often easier to adopt a new floor tile material than it is to adopt a new material for a beam."

Some US states, however, do already approve alternative structural materials such as earth blocks (made from dirt mixed with water and chemical stabilisers) or hemp.

And researchers have studied the potential of rice husk ash as an alternative to cement, either by being added to a cement mixture or by replacing cement entirely, especially as a binder in earth blocks. This would reduce the amount of cement needed in construction, lowering both carbon emissions and material costs, and means rice husk could be used as a component of structural materials.

A 2025 study proposed combining rice husk ash, wood ash and rice straw to make a low-cost, carbon-negative material that could eliminate the need for cement.

If rice husk materials like these are developed, they would be particularly useful in areas of the Global South where most rice waste is burned and billions of people lack adequate housing.

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In Africa, for example, new construction usually uses concrete and suffers from poor quality. "It’s like the worst of both worlds," says Ariana Karamallis, director of global engagement at housing non-profit Build Change, based in Colorado. When using innovative materials like rice husk, she adds, it's crucial to find a "sweet spot" between affordability, scalability and relating to the community – and to avoid testing novel techniques on the most vulnerable.

Rice husk may have the most long-term potential in rice-producing areas of the Global South, but it is already being used in buildings in the US.

Since the Park City condo project was completed, Fine has used rice husk panels in five additional projects, with several more in the pipeline. While it costs slightly more to install compared to cedar, the long-term maintenance costs are lower due to its resistance to moisture, sun and fire, he says. He believes rice husk products are on the cusp of becoming competitive and will likely beat cedar in price once more people learn how to install them.

"I'm always looking for ways to put a product out that will last a long time, longer than hopefully I'm alive," he says. Rice husk products, he says, might prove to be just such a material.

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