Richard Francis explores the implications and applications of a bio-based approach to buildings.
By bio-based we mean buildings that are constructed of natural materials (wood, bamboo, algae, etc.) or mimic biological processes (store energy and water, biodegrade without harm, etc.) The term “bio revolution” is much talked about in other industries, including medicine, food and manufacturing. There is every reason to believe that it is coming to construction and real estate. In fact, it is already here.
Traditional and innovative bio-based products are finding their way into buildings at an unprecedented pace. At the same time, wider adoption is stymied by codes and practices, not to mention a large degree of industry scepticism.
This series will look at forces driving change, factors inhibiting growth and variables that will affect how change takes place. In our final piece, we will show that there is a pattern emerging as the scope of ESG widens, one that favours a more natural, bio-based approach to buildings.
Background
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. It is impossible to achieve net zero carbon or healthy buildings without a large 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” and so on. It is no surprise that 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 is only going to grow), we suggest that bio-based principles will become further embedded in buildings. After all, the natural world has been at this (by design and for free) since the beginning of time.
From materials to ingredients
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 sounds familiar, they ought to – the food industry has been grappling with them for decades.
Any serious discussion around net zero carbon buildings now focuses on “whole life carbon” and includes all impacts from the inception of the project to the demolition of the building. 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 they have also been shown to improve the physical and mental health of occupants. 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 impact, bio-based materials are likely to be a preferred choice.
By mimicking biological processes, the built environment can meet not only today’s drivers (net zero carbon, healthy buildings) but also tomorrow’s expectations (regenerative places, circular economy, etc). Bio-based materials have also been associated with better moisture control, improved acoustics and better thermal comfort. All of these improve indoor environmental quality and enhance physical and mental wellbeing. What’s more, they do so passively, without the use of systems, further reducing the need for energy and enabling lower carbon operations.
But the benefits of natural and plant-based materials go well beyond air quality and physical health. There is a large body of research that 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.
Ingredients drive performance
The idea of “nature-based solutions” is at the core of next generation sustainability. Nature-based solutions effectively deal with climate change, water use, waste mitigation, biodiversity, health & wellbeing and so on – 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 too does the role that bio-based solutions will play.
Some of these ingredients are well known and already in place, including timber, hemp, straw, cork and the like. Others are emerging, including bamboo, mycelium and algae. Algae is particularly interesting as it shows the full capabilities of bio-based products.
Algae naturally produces a cement-like substance that is capable of bonding together 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, but which only use 1/10 of the carbon to manufacture. Algae can also be used to make a variety of other construction products, including tiles and façades.
Algae’s appeal goes beyond its carbon properties. Algae has also been used as part of 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 also demonstrating bio-based principles.
Getting beyond the conventional
Other industries facing questions about provenance, manufacturing, environmental impacts and health benefits have moved in the direction of nature-based alternatives as an answer. There is much opportunity for the construction and real estate industries to successfully follow this example. The biggest promise of the bio-based model is that companies can simultaneously meet many of the current and future challenges of the built environment in a single, simple framework.
But before that happens, institutional and cultural barriers will need to shift. In our next article, we will examine the factors holding back the adoption of bio-based materials. For although they have much promise, they will first have to surmount the hurdles of regulation, underwriting and – perhaps most difficult of all – conventional thinking.
