The building industry contributes a massive percentage of global carbon emissions. However, innovative green technology is making it possible to reduce the embodied carbon of buildings.
Using low-carbon and carbon-neutral construction materials is key to reducing a building’s embodied carbon footprint. Some examples of these materials include cross-laminated timber and mycelium insulation.
Cross-laminated timber
As the world struggles with climate change, builders are looking for more sustainable ways to construct buildings. Among the many options that are emerging, one of the most promising is cross-laminated timber (CLT). This innovative material is made from lumber glued together in layers, and it can be used to construct anything from apartments to office towers. The material is very durable and has a high strength-to-weight ratio, making it ideal for modern, high-rise construction projects. CLT is also extremely sustainable. It is made from wood that is grown in forests, and it uses fewer resources than concrete or steel. It is also more flexible than concrete, which makes it easier to adapt to changes in design.
The first CLT building in the United States was constructed in Whitefish, Montana, and is called the Long Hall. Designed by OOPEAA, the structure is eight stories tall and built from prefabricated larch timber modules. The project was the result of a collaboration between the U.S. Forest Service and the Whitefish School District to create a more environmentally friendly building. The building is a prototype for future CLT structures.
Although the use of CLT in construction has gained popularity, it is not without controversy. Critics point out that the production of the product is energy-intensive and that it can produce emissions when burned. The construction process itself can also contribute to greenhouse gasses, as it requires the removal of large trees from forests. However, proponents of CLT argue that the benefits of this alternative construction method outweigh the negative impacts of its production and use.
The use of CLT is gaining traction in the US, with a number of new structures being planned and built. The Brock Commons tower structure, for example, was constructed in just ten weeks, four months faster than a traditional building of its size. The material is also a great alternative to concrete and steel, with a low carbon footprint and reduced impact on the environment.
Solar panels
Solar panels are one of the most popular carbon-neutral building materials available today. They can be used to power both residential and commercial facilities, as well as industrial plants. Their production, however, requires a lot of energy. Therefore, it is important to use them as efficiently as possible. This way, you can cut down on your electricity costs and contribute to the fight against climate change.
A solar, or photovoltaic (PV), panel is made up of a number of individual cells that convert sunlight into electrical energy. Each cell measures about 10 x 10 cm and is protected from the environment by a glass or plastic covering. The individual cells are combined in strings to achieve the desired output voltage and current capability of a PV system. The modules are connected to each other with conducting wires sized according to the module current rating and fault conditions, with bypass diodes between each string of modules for safe operation.
The main advantage of using PV modules is that the raw materials needed to produce them are plentiful. The primary component is silicon, which is a naturally occurring element and the second most abundant in the Earth’s crust. A ton of silicon can produce as much electricity as burning 500,000 tons of coal.
Another advantage of using solar PV modules is that they are lightweight. This allows for easier transportation to the build site, which can save money. In addition, they can also be pre-fitted together before arriving at the site, which shortens construction time and reduces labour costs.
Compared to steel, wood is less costly and lighter, which can help reduce a building’s embodied carbon footprint. However, it is important to source materials with Forest Stewardship Council (FSC) certification and use eco-friendly finishes that are free of volatile organic compounds. Ideally, the materials should be local to reduce transport emissions.
Regen cement
Concrete and cement account for a large part of the carbon footprint of construction. To reduce this, it is possible to replace a significant portion of the Portland cement in concrete mix with alternative supplementary cementitious materials (SCMs) such as ground granulated blast furnace slag (GGBS) or pulverised fly ash (PFA), which are industrial waste products that significantly cut embodied carbon. These can be used at a ratio of up to 80% of the total cement in the mix.
However, these SCMs still have a high energy consumption during production. This is because the clinker used to make Portland cement has to be heated to very high temperatures. A recent innovation in cement technology, however, is making it possible to use a more sustainable fuel source. This is called CO2 capture, and it enables the production of a low-carbon concrete.
Hanson’s Regen cement uses a combination of GGBS and PFA to produce concrete with up to 70% fewer carbon emissions than traditional Portland cement. This new type of cement is made from recycled industrial waste and is able to capture carbon dioxide during its production process. It is a good choice for buildings that require a large amount of concrete, because it can limit the temperature increase during pouring and curing.
One of the biggest advantages of Regen cement is that it helps to reduce the risk of a chemical reaction known as alkali-silica reaction (ASR), which can cause cracking in concrete structures. Its use in concrete results in less heat being released during hydration and also leads to a more refined pore structure, which makes it more resistant to ASR than conventional Portland cement.
Using carbon-negative building materials is essential for reducing the embodied carbon in construction projects. This will help to offset the unavoidable emissions from other elements of a build and enable the industry to achieve zero-carbon or net-zero targets. Methods such as carbon offsetting are not enough to meet these targets, so it is important for the construction sector to adopt innovative green alternatives to typical building materials.