How sustainable is wood?

So if, like us, you’re committed to playing your part in a sustainable future for our world, knowing how to identify sustainable wood will help you to make the right selections when looking for materials for your new wood flooring, cladding or decking.

As you can probably tell, this can be quite a complex matter. With the planet’s trees being harvested at a frightening rate, it’s about more than just the environmental features of the wood itself – and it’s our responsibility to make choices that protect the world’s forests.

What makes wood sustainable?

There are many materials available for construction projects, each with its pros and cons, but none can claim to combine usefulness, availability, and sustainability as well as wood does. Here, we explore some environmental advantages that wood brings to the table.

Wood is renewable and recyclable

Compared with competing building materials such as metal, plastics, stone, and concrete, wood offers a series of benefits – key among these is that it is a renewable resource – as a natural product, wood supplies can be renewed by planting new trees and sustainable forestry.

At Thermory, we strive to contribute to the sustainable management of forests, and there is a strong movement in this area by many timber manufacturers. At the end of its use as a construction material, wood can also be re-used, recycled, or downcycled.

Wood has a smaller environmental impact than the alternatives

The level of carbon emissions from wood production is less than 100 kg of CO2 per 1,000 kg produced, compared with over 300 kg for brick and over 2,000 kg for steel.

In addition, global studies assessing the lifecycle of building materials have found that wood is less damaging in terms of air and water pollution, solid waste, and the use of energy and ecological resources.

Wood’s lifetime embodied energy – the amount of energy consumed through the production process – is more than three times lower than that of steel, plastic, and concrete, all of which also require more effort and resources to dispose of at the end of their useful life.

Wood byproducts such as bark and shavings can additionally be used as a biofuel, offsetting energy used in the production process.

It’s biodegradable

Wood that has been used in construction may still be milled and repurposed for other building or home improvement projects.

Even when it reaches the very end of its lifecycle though, wood doesn’t require a special process to return its nutrients to the earth – as long as it’s given suitable conditions, it will break down naturally itself, which also makes it ideal for composting.

By contrast, plastic can take up to 1,000 years to break down, and recycling or downcycling steel and concrete requires significant amounts of energy – albeit less than producing them as new from virgin materials.

Trees absorb carbon dioxide, and wood holds it in

As any other process, timber production demands resources, but it also offsets them in the long run. An average hardwood tree, such as alder or mahogany, will absorb around 22 kg of CO2 from the atmosphere per year, as well as other polluting gases including nitrogen oxides, ammonia, and sulfur dioxide.

The really great thing is that once the tree has been turned into wood for use as a building material, it locks the carbon dioxide away for the duration of its usage, which could be anything from a few decades to hundreds of years.

Wood makes it easier to achieve sustainability certification

When working with restrictive regulatory requirements for sustainability, wood is an ideal building material that can help when it comes to gaining permissions for a project. Wood’s versatility and sustainability features can make it much easier to attain third-party certification.

Conforming to recognized standards for sustainability can give the building project a positive public image – and in some cases, it can be the difference between getting a contract or not in the first place.

How does certification support sustainably managed forests?

Sustainable forest management means that woodlands are managed carefully and properly protected. This means that the forests are used in a way and at a rate that maintains their biodiversity, productivity, regeneration capacity, vitality and their potential to fulfil relevant ecological, economic and social functions in the long run, at local, national, and global levels. Sustainable forestry stands for not causing damage to other ecosystems or endangered species.

There are various global institutions involved in encouraging and supporting responsible forestry by setting out standards and certifying producers according to them. The best known of these are the Forestry Stewardship Council (FSC) and the Programme for the Endorsement of Forest Certification (PEFC).

The Nordic Swan Ecolabel, which is used to certify environmentally friendly products, also lays out specific requirements for wood-based products covered by the label. Meanwhile, the European Union has introduced legal measures to protect EU forests by limiting annual harvests and setting out requirements for replacing felled trees, making buying European wood a sustainable choice as the region’s timber industry now plants more trees than it harvests.

Most Thermory products can be provided with FSC, PEFC or Nordic Swan Ecolabel certification, helping our customers ensure that they buy sustainable wood flooring, decking, cladding and wall panels.

Sustainable wood treatment – how is the wood prepared?

Once wood has been harvested, it can be treated in various ways to preserve it, extend its lifespan and get it ready to use. If you’re familiar with Thermory, you’ll know that we’re all about thermal modification, which presents numerous benefits related to durability, dimensional stability, rot and pest resistance and safe and sustainable use and disposal.

The other option is chemical treatment, for example acetylation or furfurylation, where the wood is impregnated with certain chemicals, in some cases followed by additional steps such as heating. While these processes can offer sustainability benefits by enhancing the moisture and pest resistance, durability and dimensional stability of the wood, they also raise health and environmental concerns that can be avoided with the chemical-free thermal modification process.

As no chemicals are used in the thermal modification process, thermally modified wood products are safe and there’s no need to handle them as hazardous waste after use.

From sustainable wood to lasting urban environments

With the urban population steadily growing and climate change becoming a pressing topic, cities have the challenge to offer high-quality, affordable and environmentally friendly housing.

Natural resources like wood are the only truly renewable building materials. As every new-grown m³ of wood binds a full ton of CO2, wood as such is not only climate-neutral, but climate-positive. The more wood we store (e.g. in buildings), the less CO2 the atmosphere needs to deal with.

For example, Powerhouse Telemark by Snøhetta is a co-working building in Porsgrunn, Norway designed to be carbon negative and produce more energy than it will consumer over a 60-year lifespan.

Benefits of building with wood

Timber is no new construction material. Various inspiring buildings from around the world show that this naturally sustainable material can be used in creating oustanding architecture.

Compared to steel or concrete, wood can support its own weight better, which allows for larger spaces and fewer necessary supports in building designs. Even high-rise buildings have been created with it. Wood is also good material for prefabrication of mayor construction elements. This leads to a high material and time efficiency, reduced waste and cost control.

With so many tree species available, architects can construct their vision as easily as when using artificial materials. For example, timber cladding products made from pine trees tend to have distinctive knots that reinforce the natural beauty of it. Wood cladding can be painted any color needed and variety of cladding profiles give plenty of options for designing a truly unique building.

Better yet, as an organic material, wood maintain a comfortable and healthy indoor climate. Studies have shown that environments with wooden structures have positive psychological and physical effects on humans.

Read more about the positive impact of wood on health and well-being

Life cycle of wood buildings

Advanced technologies in wood production allow to prevent and forget a lot of negative processes like twisting, cracking and decay. For example, during the thermal modification process, the wood’s density decreases and its structure changes, which gives thermally modified wood many advantages.

Unlike chemical impregnation, thermal modification enhances the wood throughout, not just the outer surface, resulting in boards that are stable and durable in every sense.

With proper care, wooden houses can serve for hundreds of years and even after the material’s life as cladding, it can be reused for other use cases.

Why bother buying sustainable wood products?

It can be tempting to go for a cheaper option, but as well as negatively affecting habitats and the longevity of the planet’s forests, supporting irresponsible forestry can damage neighbouring ecosystems, cause local environmental issues, increase carbon emissions, reduce levels of embodied carbon stored by trees and result in poor-quality wood products. Over the long term, these issues can be significantly damaging to the environment.

Buying wood that has been certified by one of the above organizations gives the reassurance that you aren’t at risk of contributing to these unwanted outcomes for both the planet and your own project. You’ll also know that the forests used are being responsibly managed, meaning the producers are replacing harvested trees.

Thermory and sustainability

A big part of the reason we’re so passionate about this strong, elegant natural material is that when it comes to sustainability, the benefits speak for themselves. Because Thermory’s specialized thermal modification process doesn’t require any chemical processes, our wood is highly durable, providing strength and stability that stand the test of time.

Wood is a superb construction material – and alongside its versatility, aesthetics, and insulating properties, the environmental advantages over the alternatives only strengthen this claim.