Contribution of Cement and Concrete to a LEED-NC project

The most coveted certification is LEED NC. It is based on a points assessment of buildings based on five environmental criteria: sustainable sites, water efficiency, energy and atmosphere, materials and resources, and indoor environmental quality. Two categories are added to the evaluation system : innovation in design and regional priority to look at impacts on a local community, and expertise in sustainable design and construction and design measures.

Concrete, given its versatility, can be used for many purposes in a sustainable building project.

Sustainable Sites

Cement and concrete can earn five points out of a total of 28.

You can treat contaminated land using the Cement-Based Solidification Stabilization Technology.

To minimize any disturbance to the land by protecting the natural environment around the building, parking lots can be built on the lower floors of a building. An underground parking lot reduces the area needed for site development.

Concrete can contribute to the sound management of rainwater. Runoff can be absorbed by using concrete hollow-core paving blocks allowing plants to grow through the blocks, and water to easily penetrate the soil. Pervious concrete can be used. When it is preferable to use sealed surfaces to prevent contaminants from entering the soil, a conventional concrete slab or roller-compacted concrete is particularly suitable. Through a wide range of concrete products for water management—such as precast pipe, concrete retention tanks, and special sumps for separating waste oils and sediments from water to pre-treat the rainwater, the project owner is assured of proven product quality.

Concrete has a high albedo level. It reflects light more than a dark surface. This characteristic reduces the heat island effect, which occurs when higher temperatures are present in a given environment. This increase in temperature is due to reduced green space, which has been replaced with heat-absorbing materials, such as roofs, the walls of buildings and pavements, which are generally darker in colour.

Concrete pavements can reduce outdoor lighting requirements (i.e. parking lots) with their high albedo level.

 Water Efficiency? 

Cement and concrete can earn three points out of a total of 10.?

With effective rainwater management (previously described in the section on Sustainable Sites), water efficient landscaping is possible. Rainwater can be recovered to adequately irrigate the land using concrete water capture and storage structures. It is possible to reduce the use of potable water and treat the wastewater of a building using innovative wastewater treatment methods, which include the use of precast concrete products.

Energy and Atmosphere?

Cement and concrete can earn 26 points out of 35.?

The greatest number of LEED points is awarded to this section. Concrete can potentially earn up to 26 points for optimized energy performance. Concrete components are generally a “mass”. This means that the components have sufficient heat-retaining capacity for the heat to attenuate the daily temperature changes. Buildings made of cast-in-place concrete, precast concrete, tilted-in-place concrete panels, and insulating concrete forms or masonry have a thermal mass that mitigates extreme indoor temperatures and reduces peak heating and cooling loads.

Moreover, concrete can be used in a passive solar energy system. The sun shines on a concrete wall, which stores this energy and distributes it during the night.

Geothermal energy is a method for optimizing the energy performance of a building. A concrete piping system can be used for this type of heating.

Materials and Resources?

Cement and concrete can earn 11 points out of 14.?

Concrete is recognized for its durability. In a major renovation project, structures made in concrete can be left in place in order to preserve a large part of the building structure and shell.

On building sites, it is recommended that resources be re-used. Concrete is appropriate, since it is both re-usable and recyclable.

Concrete can contain recycled materials, such as silica fumes and recycled aggregates.In addition, recycled aggregates from crushed concrete can be used as backfill material. Reinforced steel bars embedded in concrete can also contain recycled materials.

The widespread regional distribution of concrete plants, whether for ready-mixed concrete or precast concrete, makes it possible to serve clients in a general radius of under 160 km. This distance is far below the requirements for LEED region materials. The raw materials used to make concrete are also found regionally.

The recognized sustainability of concrete increases the life of a building, whether in terms of materials, design, construction, or maintenance.

Indoor Environmental Quality

Cement and concrete can earn three points out of 15.?

Since concrete does not release gas, chemical substances, or volatile organic compounds (VOC), and does not promote mould growth, it is an excellent way of assuring indoor environmental quality, especially air quality. Concrete can be kept in its natural state for floors and walls, and save on the costs of finishing materials. Certain companies make sinks, showers, and furnishing out of concrete, which can be integrated into a LEED project. To meet the air quality requirements, concrete pipe can be used for ventilation in large-scale projects.

Innovation in Design 

Cement and concrete can earn four points out of a total of 6.

Four other points are possible through innovation and the design process. Concrete clearly demonstrates its superior performance during a lifecycle analysis. Using water-resistant concrete materials is another wise choice. A concrete covering or structural finish helps reduce VOC emissions. Hiring a LEED certified professional to be on the project team earns another valuable point.

Regional Priority?

Cement and concrete can earn one point out of 4.

A well-structured construction project will help prevent errors during the project, which could otherwise result in wasted materials. Quality and sustainability of a building made of concrete have been recognized and proven, ensuring sustainability of a structure.

There are many other ways to obtain LEED points with concrete. Use your imagination, since concrete is a highly versatile material that easily adapts to the requirements of sustainable building projects.