Introduction
How Structural Steel Supports Sustainable Design: An Overview of Its Environmental Benefits, Steel is an alloy of iron and carbon with improved strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels, which are resistant to corrosion and oxidation, typically need an additional 11% chromium. Steel is also common in the building envelope (walls, roofing), fasteners, building services, substructures and concrete reinforcement. Compared to today’s average construction practice, modern steel construction can offer.
Benefits of How Structural Steel Supports Sustainable Design: An Overview of Its Environmental Benefits
Material efficiency – resulting in e.g. less natural resource usage, less transports, less emissions and less energy usage, Ultra-high recyclability – resulting in e.g. less natural resource usage, less waste, less energy and less emissions, Quality and durability – resulting in sustainability favors, Dry construction – resulting in less health hazards, less waste, less energy usage and less emissions.
Sustainable designs/benefits of modern steel
Sustainability and construction of How Structural Steel Supports Sustainable Design: An Overview of Its Environmental Benefits
How Structural Steel Supports Sustainable Design: An Overview of Its Environmental Benefits, How Structural Steel Supports Sustainable Design: An Overview of Its Environmental Benefits. Sustainability includes environmental, economic and social concerns for achieving a long-lasting development of the society. Sustainability of Construction here comprises the major health and environmental aspects related to the life cycles of all types of buildings. The usage of energy during the building’s service state, called operational energy, is one of the most important sustainability issues for the construction sector. Energy primarily affects the environment due to the production and distribution of electricity and water for heating and cooling.
sustainability focus is on recyclability.
Embodied energy
The production of 1 kg of finished steel product for constructional usage demands about 18.6MJ/kg of energy in average, including all processes and energy types (Worldwide average). Compared to a 50-year life cycle of a multi-storey steel building, the production of all embedded steel components contributes to less than 2% of the total energy usage. As only 10-30% of the steel building is steel, the origin of the building’s embodied energy is mainly in the cement production, the lime refining for gypsum boards, iron reduction by coke and electric arc processes for scrap melting.
Operational energy
How Structural Steel Supports Sustainable Design: An Overview of Its Environmental Benefits, The operational phase includes 85-95% of the life-cycle energy usage of a multi-storey building. The framework itself has insignificant influence on the operational energy, but the thermal efficiency of the building envelope in combination with adapted building services is important. Small insulation improvements can have big influence on the total energy usage. Steel systems in exterior walls can be very efficient if used correctly.
Modern technology
shows that metal framing can be designed to have a prime performance concerning thermal performance. National building regulations set the heat flow limitations for different types of buildings. The national differences are of course significant depending on the climatic conditions, and the operational energy is directly related to the type of activity within the building. Furthermore, especially in office buildings energy is also used for cooling. In industrial
buildings heating is often at a low level as processes might produce heat or as indoor temperature requirements are low.
Transports
Combustion of fossil fuels is the activity having most influence on the mentioned environmental effects. All heavy transports, except for electrified trains supported by electricity from ‘carbon free’ power plants, emit CO, NOX, SOX, HC and other pollutants, and use finite fossil resources. Construction transports are today dominated by trucks, and the increasing international trade causes more and longer transports. Steel structures are light and material efficient, and in most cases fabricated off-site. Therefore there is less weight to transport, a minimum of waste to move to recycling or deposit, and the instant erection and low degree of in-situ production makes the logistics very efficient. The accurate design and shape stability of steel profiles also result in a minimum of constructional waste. Though, the disadvantage of a high degree of prefabrication may be additional transports between production site and construction site.
Raw materials and water
All new construction needs material, much material. Virgin materials from nature are needed when recycled material not exist in necessary amounts or quality. The virgin materials needed for steel construction are mainly metal ores, limestone, oil, coal, natural gas and some other minerals. The recycled material input is mainly steel, other metals, plaster, glass and water. Steel construction is unique because of its high degree of recycled content and recyclability, and therefore the need for limited virgin resources is relatively small. Producing 1 kg steel from ore demands about 2,5 kg of material input. The other 1,5 kg is also being used as by-products or being vaporized. In a modern production plant only about 60 g out of the 2,5 kg are sent to deposit as non-usable waste, which prove another type of excellent material efficiency.
Emissions
The emissions to air and water related to steel construction are in level with other building systems with same functions and size in a life cycle perspective. Most emissions originate in combustion of organic matter, i.e. process for material production, heating, conversion to usable energy, and also transports. Main airborne emissions are CO, NOX, SOX and dust, which cause most of the environmental effects. By amount CO stands for about 98% of the
airborne emissions. Specifying steel also means that the built in elements not will be released as emissions in the
future, as the steel and some other important steel construction materials are fully material recyclable and will not be combusted or deteriorated at a deposit.
Waste and land-use
The waste issue is primarily directly related to the issues of recycling and raw materials. The large amount of constructional waste is a big problem in some regions where controlled disposal areas are small or non-existing. In severely exploited areas, and in close-urban areas with difficult topography or other unpleasant nature conditions, green land is very attractive for man as well as for nature. Steel construction handles questions concerning waste and land-use in many ways:
• The high degrees of recyclability, reusability and prefabrication means less waste
generation,
• Off-site production means small construction sites,
• Light structures, short construction time and material strength means possible vertical
extension of existing buildings, use of developed land and construction on bad soil or in
tectonic areas,
Indoor environment
Europeans tend to spend 90% of their life indoors, and children even more. The building physics is therefore very important for health and well-being. The relationships between indoor environment and human health are very complex. Main issues are moisture, thermal comfort, sound and air quality, and the size of each issue vary between different countries.
National Regulations on Sustainability
There are many different activities on the topic sustainability in European countries. The different governments have environmental targets, both for outdoor and indoor environment, which can have an effect on the construction industry. However, these targets are often generally expressed and there are few specific environmental regulations. Environmental issues are integrated in all aspects of the building process and sustainability issues are often
dealt with in combination with other topics.
Opportunities for steel
Taken the summary of national regulations on sustainability and the trends in sustainability work, several opportunities for steel can be identified. There are also challenges to be embraced in order to secure a prosperous development as to sustainability issues for steel. It is also noticed that some of the work in the sustainability area concerning constructions are based on voluntary undertakings or related to financial questions e.g. better insurance
conditions and conditions for funding. As well as in regulations as in voluntary undertakings, opportunities and challenges can be identified.
Energy conservation
• Expose the possibilities of good thermal insulation using steel systems. Using slotted steel studs and/or external insulation or other efficient techniques a building envelope with excellent thermal performance can be achieved. . It is also of great importance to communicate the
good performance of steel systems as to thermal bridging.
• There is a challenge to communicate the excellent performance of steel systems today.
• One challenge could be the use of transports on an increasing global market. This should be an issue not only for steel, but for all materials. As to steel it could be a benefit as steel is a lighter material, thus transports have less impact and there is less waste.
Occupational wellbeing and safety
• Using steel systems, building components with low risk of acquiring problems related to moisture.
• The European procedure for providing structural safety in case of fire. This procedure is quite realistic as it takes account of real fire characteristics and of existing active fire fighting measures. It consists in estimating the real behavior of a structure subjected to the natural fire which may arise under those real fire conditions. The consideration of real actions leads to real safety and also to optimized economy Thanks to this Natural Fire Safety Concept, it’s possible to design unprotected steel structures able to ensure the stability of building in case of fire.
Life performance
• An increased lifecycle perspective is advantageous for steel as steel constructions have long life with high quality and flexible solutions. The anticorrosion solutions are really effective (coating, galvanisation, stainless steel)
• To Emphasize the low maintenance of different steel constructions.
• Steel enables the use of modular buildings for temporary locations
Land Use
• Prefabrication reduces need for space at the building site.
• Waste reduction as waste is reduced by an increased prefabrication. Also a well functioning system for recycling significantly reduces the need for deposits.
• Vertical extension reduces the need for land for e.g. new dwellings.
• Steel is an excellent material to use as to high-rise buildings.
Conclusion
Sustainable construction does not have to mean new big investments or inventing new materials, just to use “the right materials in the right combinations in the right place”. Sustainability improvements will often generate economical benefits, e.g. lower costs for heating and maintenance, goodwill and market advantages, and also a future world where we can live. The World Business Council for Sustainable Development stated that “Business can benefit from pursuing sustainability in two ways: By generating top line growth through innovation and new markets, and by driving cost efficiencies”. The benefit for man and environment is high quality survival.
