Sustainability Benefits of Energy-Efficient Construction

By Lisa Kopochinski

Over the past 20 years or so, green and sustainable construction has evolved from what many called a fringe movement to one that has definitely achieved mainstream status. Reducing energy and water usage remains the top environmental issue driving all types of construction—including school projects

Now, we are hearing much more about net-zero energy construction. Exactly, what is this and how does it differ from green and sustainable construction?

The U.S. Green Building Council (USGBC), creators of the Leadership in Energy and Environmental Design (LEED) rating system, follows a widely accepted definition of green building—the planning, design, construction and operations of buildings and spaces with a focus on the following considerations—water and energy use, indoor environmental quality, material selection, and the building’s effects on its site.

By this definition, designing, constructing and operating buildings for energy efficiency is integral to green building. Similarly, net-zero energy or net-positive energy design and construction strategies are often incorporated into green building projects. A net-zero energy building is generally defined as a building that produces at least as much energy as it uses.

“Green building starts with the understanding that buildings have profound impacts on the natural environment, as well as the people who interact with them every day,” said Anisa Heming, director for the Center for Green Schools at USGBC.

“LEED offers projects a sustainable approach to construction because it considers the building’s future impacts on the planet and on people.”

LEED, a globally recognized symbol of sustainability achievement, provides a framework to create healthy, highly efficient and cost-saving green buildings. According to USGBC, there are more than 2,300 LEED-certified schools globally, and another 2,200 that have started the process.

Perkins and Will is a global architecture firm with offices across the U.S. and international locations, including Dubai and London. Formed in 1935, the company has designed many education projects.

“Energy efficient construction can mean a lot of different things, depending on the building or the system being designed,” explained Alison Binford, senior project manager, associate at the Austin studio of Perkins and Will.

“It generally includes reducing energy consumption and minimizing reliance on the electrical grid or fossil fuels. This can be achieved through building orientation to minimize heat gain, use of efficient HVAC equipment, providing or tying into renewable energy sources (wind turbines, solar panels), and technologically advanced building system controls, amongst many other things.”

Angela Whitaker-Williams, Austin practice leader, principal at Perkins and Will said that a true energy-efficient building goes well beyond efficient air conditioning systems.

“The design approach must consider energy savings in every aspect of the building—from the way the users arrive (access to mass transit), to systems that increase or decrease energy use (lighting, HVAC, insulation), to the resources used in the building (water, lighting, consumables), and to the durability of building materials. Thinking holistically about energy reduction goes down to considering the embodied energy of how building materials are manufactured and transported. Thinking about all levels of energy required to make and use a building gives us as designers opportunities to make decisions to reduce overall energy use.”

Over the past number of years, Perkins and Will has seen a significant growth in the number of school clients focusing on energy consumption of their buildings.

“According to the U.S. Department of Energy, electric lighting in buildings consume, approximately 15% of all energy generated in the United States,” said Whitaker-Williams. “We can reduce that energy usage on artificial lighting by designing with daylighting strategies.”

This study also found that at the student level, daylighting improves student performance by an estimated 20% in math and 26% in reading. Daylight enhances health by enhancing vitamin D, mental performance, and awareness of circadian rhythms.

“In designing for daylighting, there is a careful balance of letting in the light without increasing the solar heat load on the air conditioning system,” continued Whitaker-Williams. “We use a balance of expanses of high-performance glass and shading devices”

Additionally, she said at the school district level, energy efficient building design can make excellent use of taxpayer investment as it stretches limited maintenance and operational funds. Many schools have a lifespan of 50-plus years, so designing to save 10% to 15% of the energy bills can add up to substantial savings.

At the global level, energy-efficient design limits damage to the ecosystem, reduces greenhouse gases, carbon footprint, and global warming.

One project Perkins and Will is especially proud of is the Eastside Early College High School and International High School project in Austin, Texas. With a major focus on energy-efficient design, the school is a STEM early college program focused on health, fitness and environmental science.

“Our early goals on the project was to reduce energy and use the building as a learning tool for students to easily see and understand the strategies such as looking at the variability of shading forms based on solar orientation,” explained Whitaker-Williams.

“We used the Energy Performance Calculator based on ISO Standard 13790, which is a normative tool developed by the High-Performance Buildings Laboratory of the Georgia Institute of Technology. This drove our design decisions from exterior building forms, fenestrations, daylighting, glare and building systems selections.”

For the $80-million Eastside School project, Perkins and Will team conducted computer modelling studies early in the design process to determine the most efficient strategy for building elements.

“The large overhangs at the perimeter glass were designed as a direct result of the envelope parametric analysis, which informed the exact dimensions that would maximize the shading of the glass, reducing the heat-gain, while still optimizing daylight and views for the interior spaces. This computer modeling, in addition to full energy modeling, drove the design and reduced costs for our air conditioning, as well as lighting systems,” said Binford.

Matt Wolkow is vice president of operations and engineering at Schneider Electric, which has locations throughout the United States. Schneider Electric implements capital recovery and reinvestment projects to help K12 school districts and other public entities modernize facilities, drive sustainability efforts and reduce energy consumption to achieve their vision. The company develops connected technologies and solutions to manage energy and process in ways that are safe, reliable, efficient and sustainable.

“Schools are facing shrinking budgets, rising public interest in sustainability, and limited resources for making energy saving investments,” explained Wolkow.

“We’ve worked with schools across the country that have been struggling with deferred maintenance and limited maintenance staffs to modernize their infrastructures for a lower cost through energy savings performance contracts (ESPCs)—a financial model that has been growing rapidly in popularity. It is a contracting vehicle that helps schools fund overall infrastructure improvement plans by capturing energy savings and, therefore, energy efficiency.”

Over the past 25 years, Schneider Electric has implemented more than 750 ESPC projects across the nation, saving clients nearly $2.5 billion.

Editor’s note: This story is an abridged version of a feature that appeared in the July/August issue of School Construction News.