News - The sustainable approach: Recyclable, energy-efficient steel offers unique building solutions
Brian Ribic and Ken de Souza
Jul 1 2009 12:00AM
With buildings representing approximately 40 percent of primary energy use globally and the figure set to rise, there is great potential for increased energy savings. As energy costs and consumption increase, builders face the challenge of creating increasingly sustainable spaces.
By 2050, energy saved in buildings could help reduce more carbon dioxide emissions than the entire transportation sector. Therefore, the challenge becomes an opportunity —and steel is an important part of the solution.
Construct with Steel
Recognized as a mainstay by builders, steel offers functionality, durability and strength along with environmental benefits. It is dimensionally stable and can be provided in exact sizes, which helps reduce building site waste. When it comes to reusing old steel materials, the magnetic properties of the metal make it easy to separate and move.
From an energy-savings and environmental perspective, the ability to create tight building envelopes using steel provides numerous benefits. Most importantly, creating a structure with steel helps reduce air loss, resulting in improved heating and air-conditioning performance.
In residential use, steel-built homes experience exceptional heat and cooling loss protection with the help of thermal barrier insulating materials.And, using steel helps preserve natural resources. For example, a typical 2,000-square-foot ( 186-m2) home requires approximately an acre’s worth of trees, according to the Steel Recycling Institute. When using steel, only the equivalent of six scrapped automobiles is needed.
Steel framing, for use in residential construction, contains a minimum of 28 percent recycled steel and is completely recyclable at the end of its long, reliable life. Building products made from ArcelorMittal steel can be credited, for example, with the maximum number of points for the materials and resources credit aspect of the LEED rating system.
Steel Solutions
An excellent example of steel at work in construction is the Alberta Water and Environmental Science Building at the University of Lethbridge in Alberta, Canada. Completed in 2008, the architect selected steel cladding and light-gauge steel framing for this project because it required material that was easily available and ready to use, sustainable and durable, and cost-effective.
The AWESB serves as the administrative center for the Alberta Ingenuity Centre for Water Research and also functions under the province’s investment in water research. The day-to-day activities handled in the space ensure the long-term safety, quality and sustainability of Alberta’s water resources. With this in mind, design objectives included reflecting environmental responsibility, maximizing energy and water use, and being compatible with the university’s stated preference for simplicity and geometric conciseness.
Light-gauge steel framing was used throughout the project: for exterior wind bearing walls and interior nonload-bearing walls, with prepainted galvanized steel cladding used on the two side wings of the building. The light-gauge steel framing and steel cladding allowed for faster installation than conventional framing and also eliminated the need to heat and hoard during colder periods. In addition, prepaint minimizes time and cost required and provides a high-quality finish.
The project was completed on time and on budget, resulting in an attractive, environmentally friendly space. The University of Lethbridge will be monitoring the functionality of the space and the energy costs to validate their design assumptions.
The Future
To speed up the pace at which energy-efficient practices and technologies are being adopted, the World Business Council for Sustainable Development created the Energy Efficiency in Buildings project. As a demonstration of its commitment to sustainability in construction, ArcelorMittal recently joined 13 companies in this project.
The project aims to transform buildings’ energy use, stimulate innovations and encourage new business models affecting market demand and the supply chain. Interestingly, the EEB project discovered that building professionals often overestimate the costs and underestimate the potential to reduce emissions in energy efficient buildings. Enhanced communication to shift these behavioral barriers is a key factor in increasing action on energy efficiency.
Brian Ribic is the manager of construction marketing and analysis at ArcelorMittal USA, Chicago, and Ken de Souza is the manager of global research and development, Americas, in the Hamilton, Ontario, Canada, offi ce. Visit www.arcelormittal.com.
