Straw building boom could open new market for growers

Britain’s cereal farmers produce enough straw each year to support low-carbon construction on a major scale, with researchers suggesting the material could create a new commercial outlet for growers.

The University of Bath estimates the UK produces around 9.9 million tonnes of straw annually, with supply potentially sufficient to support up to 300,000 low-rise buildings under some scenarios.

The study examined whether agricultural straw could replace some higher-carbon construction materials, including concrete and steel, while also creating additional demand for a cereal co-product.

For cereal growers, construction could provide another commercial outlet for straw alongside established markets such as livestock bedding, feed, bioenergy and horticulture.

However, researchers stressed that any significant shift into construction would need to compete with those existing uses rather than relying on an entirely unused resource.

Charlotte Taylor, lead author of the study and a researcher in the University of Bath’s Department of Architecture and Civil Engineering, said: “Straw is an incredibly common resource here in the UK.”

She added: “It’s used as livestock bedding and feed or ploughed back into fields to improve the soil. It’s also used for energy generation, horticulture, and even mushroom cultivation.”

Despite its availability, straw remains a niche building material in Britain.

“However, despite being a renewable, low-carbon and historically important building material, very little straw is currently used in construction,” Taylor said.

“In the UK, less than 20 new homes a year are built using it as a material.”

Researchers modelled several scenarios to assess how much straw could realistically be redirected into the construction sector.

They found that diverting material from other uses, including bioenergy and industrial markets, could provide enough straw for up to 300,000 low-rise buildings.

The study also found that around 60% of the straw currently left in fields would be needed to meet that level of demand.

Another scenario suggested that growing more straw on currently unused land could provide enough material for about 163,000 homes, with additional supply from other sectors still required to reach the higher figure.

The researchers said the 300,000 figure represents a potential supply scenario rather than a forecast of how many straw buildings will be constructed.

They also found that the UK has a consistent surplus of straw relative to potential construction demand, even when fluctuations in crop yields and existing uses are taken into account.

The biggest barriers, the study suggests, are likely to emerge beyond the farm gate.

A lack of established supply chains between farms and building sites, limited numbers of builders experienced in straw construction and caution among developers, lenders and insurers were all identified as obstacles.

Logistics could also prove difficult, with straw production concentrated in particular farming regions and the bulky material requiring storage and transport to construction sites.

Some straw-based construction methods are also currently less efficient than conventional techniques, which could limit wider uptake unless costs and processes improve.

The study estimates that large-scale use of straw in buildings could store between 1.8 million and 3.1 million tonnes of carbon dioxide each year for the lifespan of those structures.

Researchers also say the material could help reduce reliance on construction products with high embodied emissions.

Construction accounts for around a quarter of UK carbon emissions, according to figures cited by the study, with a substantial share associated with materials such as steel and concrete.

Straw can be used in highly insulated structural walls in low-rise buildings, but researchers argue that stronger supply chains, clearer regulation and greater confidence among builders, lenders and insurers will be needed before the approach can expand at scale.

For cereal farmers, the opportunity will ultimately depend on whether the construction sector can develop a reliable market capable of competing with established agricultural and industrial uses for straw.