Teacher's guide:

Knowledge about wood - a brilliant material!

Wood is a brilliant material with significant potential as a sustainable resource. Historically, wood has always been crucial to humanity and has been used for many purposes, ranging from the earliest simple tools to the construction of large, beautiful wooden ships. Nowadays, we even use wood to build modern skyscrapers.

Today, there is a strong focus on using materials that are good for the environment and our planet. Therefore, we are rediscovering that wood is a fantastic sustainable resource for use in construction. Trees absorb CO2 as they grow. Forests can help reduce the amount of CO2 in the air. In this way, the wood we use for construction can act as carbon storage and contribute to reducing CO2 in the atmosphere.

Here on this page, you can learn more about how wood can contribute to making the world a more sustainable place. It's about using wood to the best advantage, for as long as possible, so we generate less waste, fell fewer trees, and have a smaller impact on the environment - all while ensuring that we have enough wood for ourselves now and forests for future generations.

Reuse

Reuse is about using a product again without changing its form or purpose. An example could be a window taken out of one construction and then installed in another.

Recycling

Recycling means using materials or products to create new products or materials. It involves some form of processing of the original product or material to create something new. An example could be transforming wood from demolitions into new wood products or turning it into wood chips.

Reuse and recycling of wood

The potential for the reuse and recycling of wood is enormous, but there are some issues with how we currently use wood. We waste many resources by burning wood too quickly, and we neglect to properly care for wood materials throughout their lifespan.

Our tendency to purchase new wood instead of reusing and recycling what we already have creates significant waste and puts pressure on forest resources.

The time has come to change our consumption patterns. We need to transform our supply chains, develop new products, design differently, and rethink how we use and work with wood.

It all starts with 'saving' the wood materials that were previously considered waste. Afterward, we need to prepare the wood to be used again—either for the same purpose or something new.

This is where you come into the picture.

Task 1 of 2 (15 min.)

Feel free to copy the questions into a writing program to make it easier to write down your answers.

Work independently (7 min.)

1. Describe in your own words what reuse means. Then provide an example of wood reuse in construction.

2. Describe in your own words what recycling means. Then provide an example of wood recycling in construction.

With a partner (7 min.)

1. Read your descriptions aloud to your partner and collectively assess if you agree.

2. Identify an example together where it is challenging to determine whether it is reuse or recycling. Remember to write down your example as you will need it for the joint review later.

Benefits of building with wood

Building materials made of wood offer several advantages, including an annual reduction of 483 million tons of CO2 emissions. This is because wood replaces other materials such as concrete, metal, bricks, and plastic.

The increase in wood construction is driven by several factors:

The growing popularity of wood as a substitute for materials with high carbon footprints, such as steel and concrete.
Increased housing construction where wood is used as an environmentally friendly alternative to conventional materials.
Growing awareness of the environmental benefits of wood and its ability to contribute to climate improvements.

Source: FAO, Gresham House

In the next 30 years, it is expected that the global wood consumption will increase each year by

3,1%

Increasing demand

Wood is a more environmentally friendly material than many of the other materials we use in construction. However, a growing demand for wood for construction, energy, and wood materials is also a challenge.

The need for more wood is due to the increasing population and a simultaneous desire for more sustainable solutions. Our forests cannot meet the growing demand for biomaterials. It requires innovative solutions and a smart approach to ensure that wood remains a sustainable resource for future construction. Therefore, it is important that we use wood wisely.

Durability of wood

Stave churches are strong evidence of the durability that wood can possess.

Buildings that have stood for centuries show how wood, under the right conditions, can last for an incredibly long time. When we use wood wisely, and the construction lasts a long time - or the wood is used multiple times - it limits our need to constantly harvest new wood. This way, we can better meet the demand for wood while simultaneously reducing the need for logging and processing new wood.

En kirke af træ med sort tag og tre tårne. — Heddal Stave Church in Norway, built in the 13th century.

The two models

When we talk about waste management of wood in construction, we typically refer to two models: the linear model and the circular model.

Linear

In a linear model of waste management, a product is discarded after use. No attempt is made to reuse or recycle it, and the material is therefore used only once, after which it is considered waste and either sent to landfill or incinerated.

This results in the loss of valuable resources and a greater environmental impact.

Circular

In a circular handling of wood materials, the aim is to reuse and recycle products so they can be used multiple times instead of just once. The circular approach aims to extend the lifespan of materials and reduce the amount of waste. It requires a significant effort to enable the continued use of wood after its original purpose has been fulfilled.

This increases resource utilization and reduces environmental impact.

Burning

Wood is increasingly used as an energy source. To phase out fossil energy sources such as coal and oil, they are often replaced by energy from burning wood and other forms of biomass. It can be wood leftover from forestry, sawdust from sawmills, or wood pellets and chips from whole trees. However, some of this wood material could have extended its lifespan by being used in products or in construction before being burned.

Although burning wood waste can be turned into energy, it also results in the release of CO2 and other pollutants.

When we burn wood for energy, it is the lowest form of utility we can derive from the wood. Therefore, we should use the wood to its fullest potential before resorting to burning.

Landfill

Wood that is neither reused, recycled, nor used for energy production ends up in a landfill or a disposal facility. Landfilling is the worst option of all because it is neither good for the environment nor for society, and the wood serves no purpose.

When wood that could have been reused, recycled, or burned is instead disposed of in a landfill, it can be considered a waste of resources. Landfilling can also have environmental consequences, as the decomposition of wood releases CO2 and may release harmful substances into the soil and water environment.

When wood contains particularly harmful substances, it may be required to be sent to a landfill or destruction in specialized facilities.

Circularity of Wood

Wood is both a renewable material and has significant opportunities for reuse and recycling. There are many possibilities to extend the lifespan of wood materials and reduce both environmental impacts and the need for new wood:

Upcycling goes beyond ordinary recycling by transforming used wood products into new and more valuable items. For example, old packaging wood can be turned into wall cladding or furniture.
Ecodesign involves considering the environment when designing and producing wood products. Designing products that are easy to repair and disassemble ensures that they can be maintained and reused. It also involves using a limited variety of materials to make the products easier to disassemble and recycle later on.
Constructive wood protection is particularly important in construction, as it can significantly extend the lifespan of wood. This can include protection against sunlight, water, and moisture.
Waste prevention is also crucial. We discard large amounts of wood that could otherwise be turned into (new) products. This waste comes from sawmills, factories, workshops, and construction sites. By improving handling, reuse and recycling, we can reduce the massive waste of wood and increase its lifespan and value.

In every part of the wood's value chain, there is an opportunity for the circularity of wood.

Task 2 of 2 (25 min.)

Feel free to copy the tasks into a document for easier writing of answers to each question.

Individually (10 min.)

Describe in your own words what circularity/circular means and what linear means.
Search for "wood waste hierarchy" on the internet and describe the five steps in the hierarchy.

Together (10 min.)

Collective discussion on reuse and recycling with the presentation of your example where it is challenging to distinguish between them.
Collective discussion on the wood waste hierarchy - does it make sense?