Bio-based buildings: ‘Nature is the template for what we increasingly expect from building operations’

By bio-based, we refer to buildings constructed of natural materials (wood, bamboo, algae, etc.) or those that mimic biological processes (for example, storing energy and water or biodegrading without harm). The term “bio revolution” is often discussed in other industries, and there is every reason to believe it is coming to construction – in fact, it is already here.

Traditional and innovative bio-based products are finding their way into buildings at an unprecedented pace. However, wider adoption is stymied by codes and practices, not to mention a large degree of industry scepticism.

This series will examine forces driving change, factors inhibiting growth, and variables that will affect how change occurs. A pattern is emerging as the scope of environmental, social and governance (ESG) standards widens, favouring a more natural, bio-based approach to buildings.

The drive for net zero carbon and health and wellbeing has set in motion a new and unprecedented screening of building materials. This scrutiny has made bio-based products an early winner in next-generation construction. Achieving net zero carbon or healthy buildings is impossible without a hefty dose of natural materials.

But construction is just the beginning. Nature is the template for what we increasingly expect from building operations. This includes running on renewables, storing surplus energy, conserving water, being circular, etc. Unsurprisingly, nature-based solutions and biodiversity gains are the next big thing in ESG.

As we enter a period defined by “zero” (carbon, waste, plastics … you name it, the list will only grow), we suggest that bio-based principles will become further embedded in buildings. After all, the natural world has been at this by design since the beginning of time.

A pattern is emerging as the scope of environmental, social and governance (ESG) standards widens, favouring a more natural, bio-based approach to buildings.

The newfound interrogation of materials is striking but not entirely surprising. After all, other industries have faced these questions for years. If the issues around net zero carbon sound familiar, they ought to – the food industry has grappled with them for decades.

Any serious discussion around net zero carbon buildings now focuses on “whole life carbon” and includes all impacts from the project’s inception to the building’s demolition. The focus on embodied carbon is really a question about ingredients, “material miles,” and manufacturing processes, and so the sustainability lessons from other industries are both appropriate and instructive.

As with food, building materials that are more local, natural, and less processed are much more likely to be better for humans and the environment. Bio-based materials are naturally less carbon-intensive but have also been shown to improve occupants’ physical and mental health. One of the most effective ways to mitigate the propagation of indoor pollutants is by choosing non-toxic, sustainable, bio-based materials.

The list of available materials is growing daily and includes products such as insulation, floor and wall coverings, and even plant-based paints and finishes. Over time, we expect that more “exotic” materials like mycelium and algae will supplant conventional and more polluting traditional materials. With costs commensurate with conventional materials but with added environmental and health impacts, bio-based materials are likely to be preferred.

By mimicking biological processes, the built environment can meet today’s drivers and tomorrow’s expectations. Bio-based materials have also been associated with greater moisture control, improved acoustics, and enhanced thermal comfort, contributing to indoor environmental quality. What’s more, they do so passively, without the use of systems, further reducing the need for energy and enabling lower-carbon operations.

However, the benefits of natural and plant-based materials go well beyond air quality and physical health. A large body of research demonstrates that occupant mental wellbeing is significantly enhanced in environments where natural and bio-based materials are utilised. The use of timber in indoor settings, for example, has been linked to limiting mental stress and anxiety, promoting relaxation, improving cognitive performance, and even lowering blood pressure.

Bio-based materials have also been associated with greater moisture control, improved acoustics, and enhanced thermal comfort, contributing to indoor environmental quality.

Nature-based solutions effectively address climate change, water use, waste mitigation, biodiversity, health and wellbeing – in other words, all the things that will be expected of buildings in the near term. As the concept of ESG widens and deepens, so does the role that bio-based solutions play.

Some of these ingredients are well known and already in place, including timber, hemp, straw and cork. Others, such as algae, are emerging. Algae is particularly interesting as it shows the full capabilities of bio-based products. The plant-like organism naturally produces a cement-like substance capable of bonding sand with gravel or stone to make concrete. This “biogenic limestone” is what produces strong structures like coral reefs. By using biogenic limestone instead of quarried limestone as the filler, cement could become not only net neutral, but also carbon negative by pulling carbon dioxide out of the atmosphere and storing it permanently in the structure.

Companies have already used this process to produce bricks of comparable strength and durability to conventional bricks, which only use 1/10 of the carbon to manufacture. Algae can also be used to make various other construction products, including tiles and facades.

Algae’s appeal goes beyond its carbon properties. It has also been used in buildings to actively purify the air. When incorporated into structures and activated by sunlight, the algae generates oxygen and “eats” carbon dioxide – a perfect example of a bio-based material demonstrating bio-based principles.

Other industries facing questions about provenance, manufacturing, environmental impacts, and health benefits have moved toward nature-based alternatives as an answer. The construction and real estate industries have an opportunity to follow this example successfully.

The most considerable promise of the bio-based model is that companies can simultaneously meet many of the built environment’s current and future challenges in a single, simple framework. But before that happens, institutional and cultural barriers will need to shift. Although bio-based materials hold much promise, they must first surmount the hurdles of regulation, underwriting and – perhaps most challenging – conventional thinking.