9 Building Materials – How Much Do They Pollute Our Environment?
What is a Carbon Footprint?
The term “Carbon Footprint” is essentially describing how much carbon is being emitted by a certain object, action, or a group. It is important to keep in mind that it is also measured as a competing component to “Ecological Footprint”. Ecological Footprint measures how much we require from nature to sustain our needs. If there is carbon being accumulated in our environment, that means that there is not enough biocapacity to absorb those emissions. In the context of Ecological Footprint, it tells us how much land area and nature we need to neutralize the carbon emissions.
In the Context of Buildings…
Buildings play a huge role since human civilization. It acts as a place of shelter, a place to work and communicate, and also a place to organize a where dedicated things are in a community. As human civilization continues to improve and change, so does the buildings that we create. We began to explore different ways to build a structure, from the perspective of physics, visual aesthetics, unique purposes, and also the materials.
One of the biggest issues we are all facing right now is how to preserve our planet and slow down its deterioration from pollution. Being innovative and creating sustainable building goals is an essential part of the construction industry. The choice of materials we choose to utilize in erecting our future buildings play a huge factor in how it plays its role in saving our environment. Different building materials emit different levels of carbon footprint when being created. Let us explore below the 9 main materials used is constructing buildings today, and see how they compare to each other in terms of their level of pollution.
Our 9 Common Building Materials – Ranked Lowest to Highest in Carbon Footprint
1. Rammed Earth
Rammed Earth ranks as the lowest in carbon footprint, as it is basically an ancient technique that only uses natural raw materials such as earth, chalk, lime, and/or gravel. It is considered to be the most sustainable building method. With an average of 48kg embodied carbon per m³, it is slowly making a revival in modern buildings as it is good for the environment and has a unique and beautiful aesthetic.
2. Softwood Timber
Second most environmentally friendly building material to produce is Softwood Timber. Softwood is wood from gymnosperm trees such as pines and spruces, while hardwood is from angiosperm trees such as oaks and maples. Softwood timber emits on average 110kg embodied carbon per m³, making it a great choice to use as a finishing material for buildings, especially residential buildings.
3. Cross Laminated Timber
Third on the list for most environmentally friendly building materials is the Cross Laminated Timber. It is a very common building material used in large scale buildings, as it offers high design flexibilities, very lightweight yet very strong, easy to install, and generates almost no waste on construction site. Cross Laminated Timber is also very effective in acoustic and thermal performance. It is created by stacking several layers of dried lumber boards in opposing directions, then bonded with structural adhesives to create a straight rectangular panel. Averaging about 219kg embodied carbon per m³ in emission, Cross Laminated Timber is one of the most used building material today for its low carbon footprint.
Next up is Stone. Stone is one of humanity’s first building material, and it is as straightforward as it sounds. Stone is great in that it requires basically no manufacturing to produce as it is a fully natural raw material, and it is so durable that structures that are built thousands of years ago are still standing strong to this day. Stone emits about 237kg embodied carbon per m³, making it a very solid choice (no pun intended) for building materials.
5. Clay Brick Wall
Fifth on the list is Clay Brick Wall. Similar to Stone, Clay Brick is also one of the oldest building materials and has been used in early civilizations. It is very easy to produce, resistant, and durable to all weather conditions. Just like Stone, many structures produced with Clay Brick centuries ago are still standing strong to this day. Its production is very simple; it is simply mixing clay and water. Averaging on 345kg embodied carbon per m³, it puts Clay Brick as a decent choice of material for constructing buildings with carbon footprint in mind.
6. Reinforced Concrete
Starting to reach the high end of the carbon footprint list, is Reinforced Concrete. Concrete has a low tensile strength, and are usually reinforced by steel bars inside to make is suitable for buildings. Reinforced concrete is the most common material used today for constructing the foundation stages of a building (walls, foundation, columns, etc.) With an average of 635kg embodied carbon per m³ during the production and use of Reinforced Concrete, it makes it one of the most harmful material to our environment due to how it is commonly used and relied upon.
Seventh on the list for least environmentally friendly building material is Glass. Glass is by far a building material that we see the most today; it exists in pretty much every single building on the planet. There are laws that require structures to have a certain percentage of natural light to enter into it, make Glass a must use material. Unfortunately, Glass on average produces 3600kg embodied carbon per m³, which is a significant jump from the previous materials on the list.
8. Steel Section
Second most unsustainable building material is the Steel Section. Out of all the industries, the construction industry uses steel the most, accounting for more than 50% of the world’s demand for steel. It’s very flexible in design, affordable, and strong, but the carbon footprint that is produced from the manufacturing process to delivering is immense. With another significant jump from Glass, it carries on average 12090kg of embodied carbon per m³.
Last but not least, the one material that leaves the most carbon footprint is Aluminum. Along with Brick, Cement, and Steel, Aluminum is considered today as one of the most critical construction material. It is also an abundantly available natural resource. It is commonly used because it has a high strength to weight ratio, easy to use, low transportation cost, and low maintenance. However, the carbon footprint of aluminum is especially high compared to the rest of the list, as it brings on 18009kg of embodied carbon per m³ on average.