In our last article we looked at how plant-based products and principles can reduce embodied and operational carbon. Minimally processed plant-based building components require less energy to manufacture and can be an important part of low carbon objectives. But the benefits of plant-based building “ingredients” go far beyond carbon concerns. As with food, plant-based buildings can also be much healthier for people. The comparison of buildings to food is an apt one. In the same way that plant-based food promotes better individual and planet health, so too can buildings based on the same ideas.

If net zero is the dominant sustainability concern for our industry, then healthy buildings is a close second. Interest in healthy buildings has risen steadily over the last decade and is now a top real estate concern. But what if the same strategy that enabled net zero carbon buildings also fostered human wellness?

This is the promise of the plant-based model - to simultaneously meet many of the current and future challenges of the built environment in a single, simple framework. For example, plant-based materials are naturally less carbon intensive, but they have also been shown to improve the physical and mental health of occupants. By mimicking the things plants do naturally, 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).

In this article, we will explore how natural and plant-based materials assist human health and wellbeing. In addition, we will suggest how plant-based processes (sequestering carbon, removing toxins from the air, conserving water, biodegrading naturally, etc) represent the future playbook of an effective ESG strategy.

The rise of healthy buildings

Many people are acutely aware of what they put in their bodies, but historically they have been much less cognisant of what they put their bodies in. That is changing, in part due to recent events like COVID-19, but also as part of a more generally made connection between an individual’s environment and their personal health. The advent of technology and the profusion of environmental and personal health monitors have allowed people to be much more aware of the conditions of their surroundings and how this may impact their personal health and wellbeing.

The medical impacts of interior environments on occupants have long been demonstrated, albeit up until now mostly in the scientific and professional literature. But the rise of building certifications like WELL and Fitwel and work by various organisations such as the World Green Building Council and the UK Green Building Council have focused mainstream attention on the physical and mental impacts of buildings on personal health. The pandemic drove the point home in a dramatic way, demonstrating very clearly that indoor environments have a very real and direct impact on building occupants.

More recently, the focus on embodied carbon has brought renewed attention on materials and their manufacture. But as this topic expands, it is evident that the carbon component is only one piece of the equation, with challenges such as ensuring that our materials are safe also being a key concern to the future of the built environment.

As interest in healthy buildings increases, and as a focus on materials becomes the norm, it is very clear that building products are going to face much more scrutiny as we move ahead. This will be assisted and facilitated by the growth in indoor environmental quality monitors that have become much more prevalent since the advent of healthy building certifications and COVID-19.

How plant-based materials can help

Timber and other plant-based materials (including bamboo, cork, mycelium, etc) are non-toxic and chemical-free (provided they have been manufactured and treated in a sustainable manner). One of the most effective ways to mitigate the propagation of indoor pollutants is by choosing non-toxic, sustainable, plant-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.

As highlighted in our mass timber office series - plant-based materials have also been associated with better moisture control, improved acoustics and better thermal comfort.[1] 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 plant-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.[2]

Timber, bamboo, cotton, cork, cellulose and even algae are beginning to supplant conventional materials in sustainable construction. All of these are sourced from nature, are safe to handle and require much smaller amounts of energy to produce in comparison to the heavily processed and often chemically laden products that are typically sourced in projects.

None of these findings are particularly surprising or new – research documenting the power of natural materials (including plant-based products) has been around decades. What is driving the new interest in healthy materials is the simultaneous benefits that plant-based materials deliver – healthy buildings and low embodied carbon materials. It is possible for the number one and two concerns of buildings to be effectively mitigated by a single strategy – the use of natural, bio-based, minimally-processed plant-based products.

Beyond materials

It is not just about materials. Thinking about what plants need and what plants do can be an effective mindset for delivering low carbon, healthy buildings. For example, plants need plenty of natural light and fresh air. These are two of the most important components of a healthy building – and some of the more difficult things to deliver under wellness certifications. Utilising sunlight and natural ventilation are also important strategies for reducing operational carbon.

While very important, net zero carbon is just one aspect of ESG and any comprehensive building strategy needs to think beyond this concern, because it is only the beginning of “net zero”. We are already seeing calls for “zero plastic” and “zero toxins” in other industries. With a plant-based strategy, buildings will begin to counter these concerns.

Other areas likely to face net zero drivers include water and waste. Plants both store and use water carefully, and this will be an important consideration for future buildings. Plants also consume natural materials, biodegrade naturally and without harm. One of the leading arguments for using more natural materials in buildings is to eliminate plastic which is harmful to humans and the environment in the short and long term.

The issue around plastic waste is of particular concern for the built environment. The construction industry consumes 20% of all plastics and 70% of all polyvinyl chloride (PVC) produced globally each year.[3] The performance of plastic depends on the use of toxic additives and there are many studies raising early warnings about the growing evidence of plastic's burden on human and environmental health. That is why we are beginning to see further regulation around plastics in the US and EU.

While natural materials cannot currently fill all the roles of plastic, there is a growing interest in replacing plastics with plant-based materials where this is opportunity or reducing the need for artificial materials entirely. The plant-based model operates under the assumption that what is good for the environment is also good for humans, and when it comes to buildings this is a pretty accurate assumption. What’s more, consumers of other products have also made the connection between personal and environmental health, so presenting a “plant-based” approach to construction and operation would resonate easily.

Active building solutions

In addition to preventing pollution in the first place, plant-based products are emerging that can actively improve indoor environmental quality for occupants. There are now building products that can reduce CO2 from outside air and improve the quality of indoor environments. Whereas conventional products like drywall release volatile organic compounds (VOCs), there are new drywall alternatives that actually “eat” pollutants by capturing them from the air. Such products can eliminate up to 70% of VOCs that are present in the indoor environment.

The choice is not limited to drywall – many air “purifying” paints are emerging that accomplish the same function. They remove harmful pollutants that are generated from other products like furniture, carpets and so on.

Likewise, a plant-based approach that utilises photovoltaics to capture the sun and convert it to energy not only reduces CO2, it also can help eliminate the need to burn fuels within a building. Such burning generates NOx and other localised pollution at and near site. This is just another example where plant-based approaches have the combined effect of improving environmental and personal health.

Going forward: what to expect

We are beginning to understand that environmental and personal health are not two separate things but rather intimately related. The growing list of ESG regulation and targets will require a more systems-like thinking about buildings and their impact. This is why we think that a plant-based framework begins to make sense.

As the focus on materials expands, embodied carbon is likely to be just one concern among many. Any sensible approach to materials ought to link lower embodied carbon with other future concerns like toxins, carcinogens and so forth. To date, not enough work has been done in this area, but the profusion of technology and interest make this area ripe for further regulation, litigation, and all manner of risk. One way around this is to choose plant-based materials in the first instance, thereby anticipating the requirements of tomorrow.

We also know that organic, natural, “free from” and plant-based concepts are well-received and understood by the mainstream public. Items with these labels started out as niche products, but they are now beating conventional products by miles. Buildings are likely to be no different and so in addition to mitigating risk, a plant-based approach to places represents a very important, if currently underutilised, business strategy for the built environment. We expect that to change, and faster than we think.

Current business practice is to consider a variety of initiatives to “cover” ESG aspirations, including pursuing multiple building certifications and frameworks for design, net zero carbon, wellness, post-construction performance and so on. This is expensive, duplicative, often difficult, technical in nature, and, quite frankly, frustrating for almost everyone involved. As ESG expands rapidly, and focuses on buildings as a “whole,” there is the real possibility that today’s leading standards will have evolved by the time a project is finished, especially as the focus moves from design to performance. Therefore, thinking well ahead, around corners and beyond the current piecemeal approach to ESG is not idealistic but realistic and grounding your approach to buildings in plant-based principles may not be risky but in fact the most natural and valuable thing to do.

G&T has a wealth of knowledge and experience on best practice approaches to delivering healthy buildings. Find out more about our plant-based series and read the previous articles, or get in touch with one of our team about your project today.

[1] Also see the work of the World Green Building Council at the Better Places for People website library.

[2] For a good summary of the health benefits of wood and plant-based products see here.

[3] For a good review of plastics in construction see here.