Is Wood a Sustainable Building Material? 7 Facts

Published Categorized as Sustainability
Wood Lumber

People have been creating wooden buildings for more than 10,000 years, making wood one of the earliest building materials harnessed by humans.

Wood is generally a sustainable building material, especially when compared to plastics and metals. Most trees reach maturity when they’re between ten and fifteen years old and remove carbon dioxide from the atmosphere as they grow. However, the logging industry is a major source of carbon dioxide.

This article will discuss the sustainability of wood as a building material, which should help you decide whether to use wood for your next project.

1. Some Trees Grow Very Quickly

Hardwood trees are the primary source of wood building materials, which is why tree growth is imperative to wood’s sustainability. After all, the longer a tree takes to grow to a harvestable size, the less sustainable the wood harvested from it.

While some trees can take up to half a century to fully mature, many grow to harvestable size within ten to fifteen years. However, some reach a harvestable point much faster due to rapid growth. These species may be particularly valuable due to their sustainable nature.

The Fastest Growing Tree Species

The fastest growing tree species may be the Empress Splendor (Paulownia fortunei), which can grow up to 20ft (6m) in height in a year. This tree reaches harvestable size within ten years, making it a sustainable alternative to slow-growing hardwood species.

Other fast-growing tree species include:

  • Eastern cottonwood. This tree can grow up to 12ft (3.7m) yearly.
  • Austree hybrid willow. This hybrid willow can grow up to 6ft (1.8m) per year.
  • Thuja Green Giant. These border trees can grow up to 5ft (1.5m) annually.

2. Some Trees Can Regrow if Their Roots Are Still Intact

Cutting down a tree to harvest lumber can be destructive, especially when the tree is uprooted. But some hardwood trees can regrow from freshly cut stumps, reducing the negative impact on soil health and texture.

Tree species capable of such regrowth are valuable assets to sustainable logging operations, as they generate less soil-related pollution and help reduce the labor required to replant harvested trees.

Elms and willows are excellent examples of sustainable tree species capable of growing back from stumps.

3. Trees Can Capture Carbon Dioxide

Like other plants that undergo photosynthesis, hardwood trees produce oxygen while consuming carbon dioxide. As such, expansive lots filled with trees can help reduce CO2 levels, one of the leading contributors to poor air quality and airborne pollution.

The larger the forest (no matter how temporary it might be), the greater the carbon dioxide removal, making wood building material sources incredibly eco-friendly and sustainable.

A hardwood tree can absorb about 46lbs (21kgs) of carbon dioxide yearly, so a logging operation with 1,000 trees could reduce more than two metric tons of airborne CO2.

Oak trees tend to absorb more carbon dioxide than other hardwood species, but maples and birches are also adept at taking in CO2 and producing clean oxygen.

4. Species That Grow in Nutrient-Poor Soil Are Uniquely Sustainable

The percentage of arable land (land capable of growing crops) is limited. Still, many hardwood trees can thrive in nutrient-poor soil incapable of traditional agriculture.

This soil adaptability ensures that the supply of hardwood building materials remains sustainable.

How Soil Condition Affects Sustainability

Hardwood tree species that only thrive in moist, fertile soil can be a drain on resources. After all, growing these trees can require excessive amounts of water and fertilizer, draining local water supplies and contributing to fertilizer-related groundwater pollution.

Trees that can thrive in droughts and nutrient-poor soils need far fewer resources and generate less pollution, making them eco-friendly alternatives to more sensitive trees.

Hardwood Species That Can Flourish in Nutrient-Poor Soil

Most types of pine can thrive in dry, nutrient-poor soil, effectively making the tree one of the easiest-to-grow and most sustainable sources of wood building materials.

Some types of oak and cedar can also grow well in challenging environments, which makes them equally attractive to logging companies looking to reduce their carbon footprint and embrace sustainable practices.

5. Well-Maintained Wood Can Last Decades

Durability is another aspect to consider when determining whether wood is a sustainable building material. After all, materials that degrade quickly generate higher production needs to keep up with demand.

But most tree species don’t mature to a harvestable size until they’re at least a decade old. Fortunately, wood is one of the most durable natural materials, only falling behind dense minerals like quartz and diamonds in terms of longevity.

While wood is prone to rot when exposed to moisture, well-maintained wood treated with oil (like linseed oil) or wood tar can last a century or more.

One of the oldest homes in the world, King’s Farm (Kirkjubøargarður) in the Faroe Islands, is primarily made of wood logs, and some of its rooms date back to the 11th century, making them more than 900 years old! The thick black tar covering its exterior has helped it resist rot for hundreds of years.

Still, this centuries-old home isn’t the only example of wood building material’s durability.

The C. A. Nothnagle Log House in Greenwich Township, New Jersey, was built in the 1600s. The hardwood floor installed during the 1700s survives today. This shows how durable wood building materials can be, especially when properly maintained.

While most consumer plastics can also last hundreds of years before decomposing, wood building materials don’t contribute to soil, air, or water pollution like plastic does.

6. Logging Practices Generate Tons of Pollution

Plastic manufacturing facilities produce an average of one ounce of carbon dioxide per one ounce of PET plastic.

The global manufacturing industry produces about 82 million metric tons of PET plastic every year. Consequently, general plastic production (not including other types of plastic) generates millions of tons of carbon pollution annually.

Logging companies also produce tons of carbon each year, but those shouldering most of the blame aren’t practicing sustainable harvest procedures.

The largest logging companies often use gas-powered machines to cut down trees, and some remove the entire specimen, including the roots. Sustainable practices (like partial harvesting) may help reduce the carbon dioxide footprint from wood harvesting processes.

7. Bamboo Might Be More Sustainable Than Hardwood Trees

Bamboo is often touted as one of the planet’s most durable and sustainable wood-based building materials.

But bamboo isn’t wood.

Instead, bamboo is a relative of straw-like grasses, like marsh horsetail (Equisetum palustre). But there is some truth to the sustainable nature of bamboo building materials.

After all, bamboo can:

  • Grow up to three feet per day.
  • Survive long periods of dry weather.
  • Be used to create flooring, furniture, and a variety of textiles.

Due to the fast-growing nature of most bamboo species (most plants are ready for harvest in just four years), many companies that focus on producing raw building materials are opting to cultivate bamboo instead of hardwood trees.

But bamboo differs from hardwood in several ways, and it’s crucial to consider those differences when determining its sustainability.

How Bamboo Differs From Hardwood

Bamboo grows in tall stalks with hollow centers and thick, fibrous exteriors. This significantly differs from hardwood trees with solid interiors.

Due to bamboo’s open interior, it tends to be far more lightweight than hardwood. Transporting large quantities of cut bamboo stalks often requires less energy than hauling heavy hardwood lumber.

The growth rate of bamboo also significantly differs from the growth rate of hardwood trees. Bamboo can grow several feet daily, while many hardwood species may only grow a few feet yearly.

Additionally, some types of bamboo proliferate wildly, creating dense bamboo forests over the course of a single year. On the other hand, most hardwood trees prefer to grow apart from one another, so more land is required to grow them.

Hardwood trees can take ten to fifty years (depending on species) to mature to a harvestable point. Compare that to bamboo plants, many of which are ready to harvest after only four years!

Dried bamboo stalks can be processed into flooring planks, furniture, clothing, and cutlery (just to name a few uses). The multipurpose applications of bamboo have made it a popular resource for many commercial industries.

However, untreated bamboo isn’t nearly as durable as hardwood. Without plastic polymer coatings and strong adhesives, bamboo items would degrade quickly. On the other hand, hardwood can remain durable and resilient after a few oil applications.

Transforming bamboo into a strong building material requires pollution-generating elements. Consequently, bamboo is not the most reliable or eco-friendly building material.

The Most Sustainable Trees Used To Make Building Materials

Wood is generally a sustainable building material, but what are the most sustainable trees used to produce building materials? To find out, we’ll need to compare:

  • Water needs
  • Growth rate
  • Soil preferences

After all, a fast-growing tree can be comparatively unsustainable if it needs several gallons of water each day or nutrient-dense soil. Alternatively, a tree that flourishes in nutrient-poor soil and doesn’t require lots of water can be less sustainable than others if it grows slowly.

By weighing these three essential factors, we can determine which hardwood trees and woody plants are the most sustainable option for building materials. The helpful chart below breaks down each element for various species that are often lauded as being highly sustainable.

Tree Name and SpeciesWatering FrequencyGrowth RateSoil Adaptability
Austree hybrid willow (Salix matsudana x Salix alba)Immediately after planting: twice per week
After three months: once per week
About 6ft (1.8m) per yearAdaptable; survives in most soil types
Black cherry (Prunus serotina)Immediately after planting: once per week
After three months: twice per month
About 3ft (0.9m) per yearSemi-adaptable; doesn’t thrive in water-saturated soils
Eastern cottonwood (Populus deltoides)Immediately after planting: once per week
After three months: once per week
About 12ft (3.7m) per yearSemi-adaptable; doesn’t thrive in water-saturated soils
Eastern white pine (Pinus strobus)Immediately after planting: once per week
After three months: once per week; less during heavy rainfall
About 2ft (0.6m) per yearHighly adaptable; can survive in dry, nutrient-poor soils
English elm (Ulmus procera)Immediately after planting: once per week
After three months: once per week
About 3ft (0.9m) per yearAdaptable; survives in most soil types
Quaking aspen (Populus tremuloides)Immediately after planting: once per week
After three months: once per week
About 2ft (0.6m) per yearAdaptable; Survives in most soil types
Tortoise shell bamboo (Phyllostachys edulis)Immediately after planting: once per week
After three months: once per week
About 25ft (7.6m) in one year (maximum height)Semi-adaptable; grows well in fertile soils that are kept moist
Tulip tree (Liriodendron tulipifera)Immediately after planting:once per week
After three months: once per week
About 2ft (0.6m) per yearAdaptable; survives in most soil types
White ash (Fraxinus americana)Immediately after planting: twice per week
After three months: once per week
About 2ft (0.6m) per yearAdaptable; survives in most soil types
White oak (Quercus alba)Immediately after planting: once per week
After three months: twice per month
About 2ft (0.6m) per yearAdaptable; prefers moist soil but can tolerate droughts

After comparing water needs, soil preferences, and growth rates, it seems that the most sustainable type of tree is the Austree hybrid willow. Though it’s not the fastest growing tree, its soil tolerance and comparatively low water requirements make it highly sustainable.

Final Thoughts

Wood is a sustainable building material. Growing trees can help remove carbon dioxide from the atmosphere, and wood harvested from fast-growing trees requires few resources (fertilizer, water).

Most types of hardwood are exceptionally durable, so they enjoy longer lifespans than single-use plastic or rust-prone metal materials. Some tree species can regrow if their roots and stumps are left intact, which makes reforesting a lot easier compared to when cutting trees down to the roots.

However, the logging industry produces millions of tons of carbon emissions each year. Sustainable tree-harvesting practices may help offset this pollution.

Sources

By Giovanni Valle

Giovanni Valle is a licensed architect and LEED-accredited professional and is certified by the National Council of Architectural Registration Boards (NCARB). He is the author and managing editor of various digital publications, including BuilderSpace, Your Own Architect, and Interiors Place.

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