10 Sustainable Building Materials for Schools

Published Categorized as Sustainability
Sustainable Building Materials for Schools

Given the dire state of the planet’s health, there’s growing emphasis on green building worldwide, and choosing sustainable building materials is key to that. So as you design a school to secure the future of children, you might want to consider using sustainable construction materials to help protect that of the planet, too.

Some of the most sustainable building materials for schools include bamboo, wood, rammed earth, cork, precast concrete, reclaimed metal, Insulating Concrete Forms (ICFs), shipping containers, timbercrete, and recycled plastic.

In the rest of this post, we’ll explore in detail what makes these materials sustainable and review the most important factors to consider when choosing eco-friendly construction materials for your school project.

1. Bamboo

Bamboo is a perfect sustainable alternative to wood. And while it resembles wood in many ways, bamboo is a member of the grass family — meaning it’s quicker to regenerate than trees. In fact, the world record for the fastest-growing plant is held by a certain bamboo species that can grow 35 inches (91 cm) per day or at a rate of 0.00002mph (0.00003 km/h).

Bamboo’s rapid rate of growth is, for the larger part, what makes it sustainable. You can harvest it for building purposes every three years, as opposed to waiting 25-50 years for trees to mature (depending on the type of the tree).

So by choosing bamboo as a building material, you’ll help allow forests to regenerate, which is great for the planet’s sustainability. In return, you’ll get to use a building material with excellent strength-to-weight ratio and resilience.

You can use bamboo for a variety of building applications, including flooring, cabinets, scaffolding, roofing, and much more. You’ll especially appreciate the fact that it can take some abuse without replacing too much, which isn’t always the case for other fast-growing, renewable products like hemp.

2. Wood

As far as historically popular building materials go, wood is second only to stone in the construction industry. Over the last thousands of years, this flexible material has been used for all kinds of construction, and you, too, can use it to build various structures and furniture in your school.

One of the main advantages of using wood for construction is that it is a readily available and affordable natural resource, especially in forested areas. It’s strong, relatively lightweight, and provides decent thermal insulation compared to other materials such as steel. Not to mention that wood is a versatile material that you can use for almost any construction application because it’s easy to cut into all kinds of shapes and sizes.

So, while wood does do some damage to our forests, it’s still a decent example of a sustainable construction material, especially when you compared it to plastic and other petroleum-derived construction materials. It’s biodegradable, renewable, and leaves a smaller carbon footprint compared to steel, cement, and plastic.

That’s particularly true for wood grown and harvested with emphasis on sustainable forest management. Bluntly put, these are forest management principles that strive to strike a balance between society’s demand for forest-derived products and the preservation of forest diversity and health.

Sustainably managed forests allow us to take advantage of wood products without tipping off this balance, and you help make the planet healthier by only building with wood grown under such programs.

3. Rammed Earth

Earth-building is one of the oldest trends. China’s Great Wall, buildings in Early Roman empires, and the Alhambra Palace were all constructed using mainly rammed earth, and these are just a few examples. But while earth building has a long history with mankind, its incarnations can also be seen in modern luxury buildings, albeit with some tweaks to produce robust dramatic walls that resemble sedimentary rock. 

Rammed earth walls (or even floors) provide great thermal storage, allowing the sun to warm them up during the day and then retaining the heat to warm up interiors when it gets cold. This makes rammed earth ideal for building school structures, particularly in areas that experience extreme temperature fluctuations.

In terms of structural strength, it doesn’t disappoint, either. When properly prepared, this material can be used to build multi-story load-bearing buildings and has interestingly been used to construct leaning walls in some parts of the world. 

And since walls made of rammed earth don’t require much embodied energy to construct, it qualifies as a sustainable building material. Such walls are made by ramming a mixture of aggregates (including sand, clay, gravel, and silt) between flat panels known as formwork.

Traditionally, a wood pole was used to repeatedly ram the aggregate mixture, but modern technology has replaced the pole with an automated mechanical ram. Apart from the ram, there aren’t too many machines used when building with rammed earth, and that minimizes the carbon footprint.

Advancement in building technology has also created a variation of earth building that uses a unique kind of building block known as Watershed Block. Meant to reduce the carbon emissions caused by intensive use of cement in modern construction, these blocks recycle quarry waste materials to create blocks with half the cement of concrete masonry blocks.

4. Precast Concrete

Precast concrete contributes to sustainable building practices in a number of small, but cumulatively significant ways:

  • For starters, the unique water-cement ratio in this type of construction material makes it very durable and isn’t possible with other cement-based concrete types. Such durability means you won’t have to repair or remake your buildings frequently and will help minimize the environmental impact of construction waste.
  • Its great thermal mass allows it to absorb heat when it’s extremely hot and release it slowly into interior spaces when it gets cold. This helps regulate interior temperatures without overly relying on HVAC systems, which is certainly great for the environment. 
  • While precast concrete is factory-formulated, there’s little waste involved in the manufacturing process. That’s because many plants specialized manufacturing techniques and technology to reduce waste from things like excessive concrete use on construction sites, packaging, formwork and bracing, and debris accumulation on cast-in-place sites.
  • During manufacturing, materials that would otherwise go to a landfill (slag, silica fume, and fly ash: just to name a few) are recycled and incorporated into precast concrete. Even though these are used as supplementary materials, they help further minimize the industrial waste associated with the manufacturing process as well as the amount of cement used in precast concrete.
  • Most of the raw materials for making precast concrete are locally sourced, and most times, the manufacturing plant is located near the aggregate mine. This significantly minimizes the amount of fossil fuel used in transportation and, as a result, helps reduce carbon emissions. 
  • Precast concrete doesn’t release volatile organic compounds (VOCs) or other toxic chemicals into the environment when left exposed.

Indeed, precast concrete is one of the most sustainable materials for building schools, and it doesn’t come up short in terms of structural excellence. Buildings made with this material don’t require as much thermal regulation as those built with traditional concrete and are typically more durable.

5. Cork

Like bamboo, cork is a natural resource that grows rapidly. However, it has one major sustainability point over bamboo: It’s harvested from the bark of a living oak tree, which usually continues to grow and reproduce the building material. That means no trees have to die to produce the material, which is great for our planet’s health.

Cork’s great structural strength and wear resistance make it ideal for floor tiles. Meanwhile, its ability to absorb noise makes it perfect for sound insulation sheets, and its shock absorption qualities make it ideal for subflooring.

One of the main advantages of using cork for construction is that when uncoated, it’s resistant to fire. That, however, doesn’t mean it won’t burn. But even then, it won’t release poisonous gases into the environment. The material is also almost waterproof, meaning it won’t retain water and lead to issues like rotting or mold.

The only major issue you might have with cork as a building material is that it does get brittle over time. However, this might not be a problem in some applications, and your contractor may be able to help you work around it. If they can’t, you can always switch to bamboo or another appropriate sustainable material depending on your construction needs.

6. Reclaimed Metal

It’s no secret that aluminum and steel are high on embodied energy. These materials use up a lot of energy in their production through things like processing the ore, heating, forming goods, and transporting heavy equipment. 

Every time you reuse or recycle any of these metals, you’ll be helping reduce the embodied energy. This is great for sustainability because repurposing these metals means you won’t be creating more demand for them. However little the effect that might have on the overall demand for metal, it’ll make a difference in the planet’s health, especially if more people do it.

The great thing about using reclaimed metal for construction is that it lasts long and does not need frequent replacement. It also doesn’t burn or break easily, making it a viable option for roofing, structural supports, and other tons of construction applications.

In other words, building with reclaimed metal won’t be any different from using brand new metal. You’ll still get the same structural excellence of ordinary metal, only at a cheaper price; not to mention that you’ll be doing something great for the environment.

7. Insulating Concrete Forms (ICFs)

Insulating Concrete Forms (ICFs) refers to a system of formwork used to create cast-in-place concrete walls sandwiched between two layers of insulation material. Walls with this kind of construction have great structural strength and energy efficiency.

While ICFs are usually left in place as permanent substrates for walls, it’s not easy to tell if a building has this kind of construction. That’s because traditional finishes are usually applied to both interior and exterior faces, making the walls identical to traditional ones except with extra thickness.

ICF’s sustainability as a construction material for schools, homes, and residential buildings stems from the fact walls made with the material are virtually airtight, which helps reduce heat loss. By preventing the loss of heat through walls, this insulation material makes buildings more sustainable by minimizing reliance on HVAC systems.

Indeed, ICF has a high R-value of above 3 K·m²/W (in American units: R-17), which basically means it’s great at resisting the flow of heat through it. In a 2012 technical bulletin, Logixicf calculated the R-value of 4” ICF-fitted wall section and compared it to a 6” stud wall with R-19 batt insulation. They found that the wall with ICF had a higher R-value, which translates to better thermal insulation.

So by building your walls with ICF insulation, you’ll be helping protect the environment. In return, you’ll benefit from:

  • Lower electricity bills
  • Better soundproofing
  • Mold, mildew, rot, and insect resistance 
  • Strong walls

8. Shipping Containers

Shipping containers are an excellent example of high-quality waste in our society. There are millions of these vessels all over the world and are only used for shipping. After use, they ‘re disposed of, often when they’re still in great shape.

To help reduce this waste, you can repurpose shipping containers into all kinds of structures when building a school. This will be pretty easy, too, because these vessels are easy to mold to fit infinite design choices. Plus, they’re usually built to last (with steel or aluminum), meaning whatever you choose to build with them won’t require frequent repairs.

9. Recycled Plastic

Recycling plastic is one of the best ways to protect the environment from all kinds of pollution. If you need a reminder of the damage, it can do to our environment, just take a look at the nearest dumpsite. That’s not to mention pollution from the manufacturing process, and the harmful gases it releases into the environment when it burns.

By using recycled plastic when building your school, you’ll help reduce its overall demand since you won’t have to buy more of it. You’ll also be putting plastic that would otherwise end up in a dumpsite to good use, which helps reduce waste.

There’s a ton of ways you can repurpose plastic in construction, but perhaps the best way to do that without compromising operational efficiency would be to use products made of recycled plastic. These can be tiles, insulation materials, structural lumber, bricks, windows, fences, carpeting, or even concrete. 

The beauty of building with such products is that you’ll still get the same operational and structural efficiency you’d expect from each, but with the added benefit of lower cost.

10. Timbercrete

Timbercrete is an award-winning, environmentally-sensitive building material that can be pressed into a wide range of sizes, shapes, colors, and textures. Its sustainability as a construction material is due to the fact that timbercrete is made from wood waste such as sawdust and discarded pallets.

Since its production uses wood that would otherwise go to waste as the main raw material, more trees don’t have to be cut down to make timbercrete, and this is good for the planet’s sustainability.

Timbercrete ‘s unique density and matrix give it better acoustic and thermal insulation properties compared to traditional bricks. It has unique resilience and excellent load-bearing capacity, too, yet it allows you to nail or screw into it like wood. Also, timbercrete blocks are usually larger and lighter than their brick counterparts, and this helps make construction easier and faster.

Better yet, timbercrete is more resistant to the transmission of airborne sound than aerated concrete, meaning it’s better for projects where soundproofing is a priority. At the same time, it provides less sound deflection than higher-density clay and concrete, meaning echo and reverberation will be less of a problem in structures built with timbercrete blocks.

Such acoustic properties make timbercrete ideal for building schools, especially given that children are always loud.

What to Consider When Choosing Sustainable Building Materials for Schools

Sure, choosing any of the above materials is one of the easiest ways to incorporate sustainable building principles in your school construction project. However, different materials designated for the same purpose may vary in terms of sustainability “rating,” and there are considerations to be made when shopping.

To make your school’s buildings as green as possible, consider the following factors when choosing the construction materials:   

Reusability: Reusability largely depends on the durability of the material. Generally, the more durable the material is, the higher the chance it’ll have several years of service life left in it when you decommission an old building. That means it’ll still be in good condition, and you can remove and use it in your next project.

Biodegradability: This simply refers to a material’s potential to decompose naturally when disposed of. Generally, organic materials are faster to decompose and return to the earth, while synthetic ones like plastic take a long time.

But while choosing highly biodegradable materials will certainly help with sustainability, perhaps a more critical consideration would be whether the material in question releases hazardous substances as it decomposes.

Recyclability: Recyclability denotes a material’s potential to be used in the creation of new products. Steel is the most popularly recycled building material, mainly because it’s easy to separate from demolition debris using magnets. Many materials, particularly those that are integrated into building products, are not easy to separate, and this makes recycling difficult.

So when choosing sustainable materials for construction, you should think about how hard it would be to extract each type from demolition rubble should you choose to decommission the building. This way, you’ll encourage recycling, which is great for the environment.

Renewability: Generally, materials that come from renewable resources are more sustainable. Cork, for instance, is more sustainable than wood because it’s extracted from the bark of a tree that continues to live and regenerate the material.

Energy Efficiency: Energy efficiency also contributes to the sustainability rating of construction materials. One of the main goals of sustainable building is to minimize the amount of generated energy that has to be used in a building, and that largely depends on the energy efficiency of the materials used. 

Depending on the material type, this can be measured through:

Final Thoughts

Hopefully, this roundup will help you choose environmentally-friendly materials for your school construction project. But as you make that choice, keep in mind that while helping keep the planet healthy is important, your project’s success is, too.

In some cases, choosing a sustainable material might mean compromising on structural excellence, cost, and operational efficiency. Ultimately, it’s up to you to strike a balance between saving the planet and building the best school within your budget, in the most efficient way.


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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