Going Green And Sustainable With Steel
The future global challenge for the construction industry is clearly to meet the world’s growing needs while at the same time limiting the impact of its burdens. Is steel the construction material that will lead us towards a green and sustainable tomorrow?
We should be aware that the building industry provides 5% to 10% of worldwide employment and generates 5% to 15% of the GDP. Meanwhile, the built environment accounts for 40% of energy consumption, 40% of CO2 emissions, 30% of the consumption of natural resources, 30% of waste generation and 20% of water consumption. Necessity is the mother of invention, they say, and the journey of steel has been driven by need as well. Whether you are concerned about climate change or not it’s on a lot of mind these days. Owners may be shooting for a LEED rating or simply want to know what impact a steel building has on the environment.
Greenhouse gas emissions have been reduced significantly in the creation of steel (-20% in CO2 emissions and energy consumption over 20 years). Milling steel takes almost no water. Any water used is recycled back to the environment, cleaner than when it was taken).
Durability
Steel is durable; a steel building will stand for decades with minimal maintenance. When treated correctly it doesn’t corrode. Steel unlike other materials doesn’t require a new coat of paint every year hence lesser maintenance required.
Flexibility
Steel frame is flexible, thus, super-resistant to dynamically changing natural forces like wind and earthquake.
Ductility
Steel is ductile in nature, hence indicates or warns before failure
Pre-fabrication
No waste is created at the jobsite. The building frame and panels arrive ready for assembly.
Because steel is light for its strength, the foundation requirements are reduced and fewer resources used to engineer it. Steel piles or traditional foundations are used which can be disassembled after the building life is over. On the contrary, it is not feasible to pre-manufacture a wood frame or concrete structure.
Prefabrication also allows the pre-fitting of windows and doors to ensure a tight seal to eliminate air leaks that drain energy.
When you replace greenery with concrete more solar energy from the sun is pulled into the earth resulting in a phenomenon known as heat island effects. The reason behind this phenomenon is reflectance. A black or dark color roof may reflect as little as 10% of received solar energy. A white or steel roof may reflect as much as 90% of solar energy. Put another way, a steel roof can reduce the absorption of solar energy from 225 to 25 watts per square meter.
Thermally efficient
Although steel readily transfers heat, it is easy to install insulation within the steel frame under the wall and roof panels and the floor system. Insulated roof and wall systems can significantly reduce HVAC costs.
Further Energy Saving with Solar
If saving energy due to your home’s superior insulation wasn’t enough, be mindful of the fact that steel frame homes are amazingly strong and can support solar panels without a problem. Solar panels add value to your home while reducing your energy bill, since you are creating your own! A typical return on investment for a solar panel is 15-20% and the investment continues to grow as energy is becoming more and more costly.
High Strength to Weight Ratio
Firstly, Steel has a high strength to weight ratio; therefore it takes less material to construct a building of a specific size and design than if you were to use wood or concrete. Hence resultant conservation of natural resources could be from 30% up to 70%.Secondly, high strength steels reduce the weight of trucks allowing them to carry more goods for the same amount of CO2 emissions per km.
Lastly, Steel’s compressive & tensile strength is equally good, whereas concrete has approximately 1/10th the tensile strength of steel.
End of Life
The concept of circular economy needs to be adapt which refers to a move from linear business models, in which products are manufactured from raw materials, used and then discarded, to circular business models where products or parts are repaired, re-used, returned and recycled. This is all based on a life cycle approach. In a well-structured circular economy, steel has significant advantages over competing materials. Four keywords define these advantages: Reduce, Reuse, Remanufacture and Recycle.
Recyclability
Steel is a unique material in its capacity to be continually recycled without loss of properties or performance. For instance; Steel’s strength does not wear down, creep or buckle and can easily be repurposed for other projects. It is also 98% recyclable, placing it at the epitome of environmentally-conscious building frame materials.
Steel’s recycling rate reaches high levels: 98% for beams, 65-70% for reinforcement bars. It can also be easily recycled into new studs, joists and other components used in construction of new buildings. The recycling of steel also reduces the burden of disposal in landfill facilities and prevents the accumulation of otherwise abandoned steel products.
Reusability
The use of steel scrap reduces carbon emissions from the steel life cycle. In addition to this, production of steel results in the generation of byproducts that can reduce CO2 emissions by substituting resources in other industries. For example, steel making slag is also used as civil works aggregates thereby saving natural resources and reducing environmental impact.
Steel is more durable than any other construction material and can be disassembled and reassembled or reused at the end of the building’s life.
GREEN Certificate
Steel is the only building material with an automatic default value for recycled content in the LEED program (Steel Framing Alliance, 2016), making it more sustainable. It meets the requirements of the world’s leading green construction certifying agencies, such as the National Green Building Program, which certifies residential buildings, and the US Green Building Council’s LEED program, used for both residential and commercial structures.
Conclusion
“The greatest threat to our planet is the belief that someone else will save it.”– Robert Swan, Author However, steel is that viable alternative that may transform our tomorrow. It can become a leader in the environmentally conscious age in which the construction industry is about to enter. If we’re prepared it is possible that industry and nature will coexist on some of the largest scales imaginable.
