The steel industry continues making inroads in advancing sustainable construction and because of its high strength-to-weight ratio steel is being used on more and more projects. Today there are even steel buildings with low to zero carbon ratings.
It’s the efficiency of steel as a resource that lends to its credibility as a sustainable product. Made from an abundant earth material, it is also 100% recyclable and it can be infinitely recycled without loosing its preferred properties. In fact, the worldsteel association reports that steel used in construction has a recovery rate of 85%. Steel is also heavily reused, or repurposed, and steel makers are increasingly designing products with reuse in mind.
Structural beams, and roofing and wall elements top the list of steel items being designed with reuse as a criteria. Even though many steel barrels have lives of just six months, when reused 10 times the lifespan extends to five years. It’s common for railroad tracks to be switched left to right to extend use on main lines. When rails become too worn for high volume tracks they can be analyzed for cracks and then installed on tracks with lighter traffic. Even complete units such as wind turbines can be moved to other locations when being replaced with more powerful ones.
There are several reasons why sustainability continues being an important consideration in development and in construction. Population growth tops the list, followed by a doubling of material consumption every 20 years. Global warming, inefficiencies in production and dwindling resources taken together put an increasing strain on the environment and on future development. Construction alone is responsible for consuming 40% of global energy and raw materials, and moving construction materials can account for 10% of a country’s energy expenditure.
When construction businesses understand the challenges of sustainability there are steps they can take to improve it.
The first is to make wise choices when it comes to the materials selected for projects. Almost all industries now have information on the sustainability of the products they produce making it easier to choose wisely based on the needs.
In the design phase, owners and developers can scrutinize opportunities for using low-enegy solutions and for minimizing environmental impact. The design phase is also a good time to consider what future uses the building might have so that at the end of its original use it can be more easily adapted. Another tactic is to exceed building regulations. For example, some current building regulations require a maximum air leakage rate of 10 m3/m2/hr, whereas pre-finished steel clad buildings are regularly achieving a rate of 3-42-3 m3/m2/hr, (this is complicated but if you want to dig into it check out this PDF).