Articles da finire 58 Building Future

Green & Sustainable: Building for the Future

By: Kendall Jones on October 4th, 2016

Over the past two decades, green and sustainable construction has evolved from a fringe movement to achieving mainstream status. In a recent study conducted by Booz Allen Hamilton for the USGBC, they expect green construction spending to increase from $150.6 billion in 2015 to $224.4 billion in 2018. The study also predicts that between 2015 and 2018, green construction will generate $303.4 billion in Gross Domestic Product (GDP), support 3.9 million jobs and provide $268.4 billion in labor earnings.

Drivers of Green Building

Market and client demand have been two of the major forces driving green construction. Over the past few years, we have also seen a number of state and local governments adopting regulations, requirements and initiatives focused on green and sustainable buildings.

Reducing energy usage and water usage are the top environmental issues driving green construction. In 2015, residential and commercial buildings accounted for nearly 40% of U.S. energy consumption, according to the U.S. Energy Information Administration. Reducing construction waste, lowering greenhouse gas emissions and conserving natural resources are some of the other environmental concerns that are forcing us to reevaluate how our buildings are constructed.

A number of states including Maryland, Washington and Colorado have green requirements for state-funded public building construction and renovations. The California Public Utility Commission has set net zero energy goals for all new residential construction by 2020 and commercial buildings by 2030. Zero net energy buildings create as much renewable energy as the building consumes in a year. Federal agencies like the General Services Administration and the Department of Defense also have green requirements for new construction and major renovations.

The private sector is also in on the action. Companies like REI, Columbia, PNC Bank and Harris Teeter all have green retail locations. Kohl’s Department Stores announced a major commitment to conserving the environment by encouraging long-term sustainability.

Walgreens built the world’s first net-zero energy retail store in Evanston, IL. The new store produces renewable energy from three separate sources: a geothermal energy system, over 800 solar panels and two 35-foot wind turbines. Corporations like Google, Apple, Facebook, Starbucks and Nike have all committed to using 100% renewable energy for their operations.

Here are some of the trends shaping the future of green and sustainable construction.

Renewable Energy

Renewable energy, primarily solar, wind and geothermal, continue to gain in popularity as sustainable alternatives to power the built environment. Solar panels are being integrated into everything from roof shingles to building façades to road pavers.

Initiatives like the Paris Agreement to reduce greenhouse gas emissions and combat climate change and net zero energy building goal in California are moving us toward greater adoption of clean and renewable energy sources. Earlier this year at the North America Leader’s Summit, the leaders of these three countries established a continental goal of converting to 50% clean energy by 2025.

Net zero energy buildings, buildings that create as much energy as they consume, and even net positive energy buildings, buildings that generate more energy than they consume, are coming to the forefront. Net zero and net positive energy buildings happen through a combination of design, energy efficiencies and renewable energy production. Use of renewable energy is rapidly increasing as costs to implement continue to fall.

Healthier Buildings

Constructing healthier buildings has been gaining in popularity over the past few years. Owners and developers have started realizing the benefits of healthy buildings, for both the building occupants and their bottom line. Two of the main contributors to delivering a healthy building is improved or increased daylighting and better air quality.

Eliminating the presence of volatile organic compounds (VOCs) in building products such as furniture, paints and carpeting can go a long way in improving air quality in a building. VOCs are compounds that can easily become vapors or gases and short-term exposure can cause irritation of the eyes and respiratory tract, headaches and dizziness. Long-term expose can damage organs such as the liver and kidneys as well as the central nervous system.

A move to create greater transparency in building products to satisfy the need for architects and specifiers to be able to identify building products that are healthy, sustainable and environmentally friendly has been growing. The two most well-known and widely used building product declarations are environmental product declarations (EPDs) and health product declarations (HPDs).

HPDs concentrate on disclosing a building product’s list of ingredients and their health effects. EPDs focus on the environmental impacts of a building product throughout its lifecycle. EPDs provide a building product’s environmental data based on its life cycle assessment (LCA).

The WELL Building Standard, launched in 2014, focuses on enhancing the health and well-being of people through the built environment. The standard measures, certifies and monitors building occupant health and well-being in seven categories: air, water, nourishment, light, fitness, comfort and mind.

Green & Sustainable Building Materials

According to a study by BCC Research, the U.S. market for green building materials is expected to grow from $43 billion in 2014 to $69 billion in 2019. Green building materials cover those that are made from renewable resources, are recyclable at the end of their life, manufactured using environmentally friendly processes, made from salvaged, recycled or waste content or is beneficial to the interior built environment.

Concrete and steel are two of the most commonly used building materials in the world. The problem is the production of steel and concrete materials account for about 8 - 15% of global greenhouse gas emissions annually. Innovations in the manufacturing processes of these two building materials are helping to reduce those emission amounts, but we’re still a long way off from being able to call them green and sustainable building materials. This is why there has been a push from some advocates to use mass timber in place of steel and concrete in larger projects such as skyscrapers.

Examples of mass timber include cross-laminated timber (CLT), laminated strand lumber, laminated veneer lumber and glue-laminated timber. If the timber is sourced responsibly, it provides a completely sustainable and renewable building material. Carbon emissions from manufacturing mass timber products are a fraction of those created by the production of steel and concrete and CO2 absorbed during the tree’s life remains trapped in the building products produced.

The Cradle to Cradle Certified Products Standard (C2C) is a certification tool used to rate the green profile of manufactured products covering everything from building materials to clothing to office supplies. The C2C verification focuses on a product’s toxicology, recyclability and manufacturing processes. To get certified, a product must satisfy material health, material reutilization, renewable energy, water stewardship and social fairness benchmarks.

Stringent Building Certification Programs

For years, LEED was the only game in town when it came to green building rating systems. In 2000, the U.S. Green Building Council (USGBC) only had 24 projects certified in its Leadership in Energy and Environmental Design (LEED) rating system. Today, that number has grown to 26,643 certified projects in the U.S. comprising nearly 3.5 billion gross square feet of building space.

The USGBC established their LEED rating system back in 1998. The current iteration, LEED v4, was launched in 2013 and expanded to cover 21 market sector adaptations by including things like data centers, existing schools and warehouses and data centers. With each new version of LEED, new credits and prerequisites are added or altered to incrementally create a more rigorous certification process. This measured approach, while strengthening the standards, has made it easier to adapt to stricter requirements with each new version.

The Living Building Challenge, which is administered by the International Living Future Institute (ILFI), is hands down the most stringent green and sustainable building certification program. To be certified as a Living Building, the project must meet the requirements seven performance areas or “Petals”. The seven Petals include site, energy, water, health, materials, equity and beauty. The seven Petals are subdivided into 20 imperatives with each imperative required to be met in order for a project to be certified as a Living Building. These imperatives include requiring that the building is built on a previously developed site which includes greyfields and brownfields. The project also has to achieve net zero water and net zero energy.

The International Green Construction Code (IgCC), while not a rating system, was developed to govern the environmental impact of buildings and structures through model code regulations that promote green and sustainable construction. The IgCC was developed in conjunction with a handful of sponsors including the American Institute of Architects (AIA) and ASTM International. Adoption of the IgCC has been on the rise with cities like Dallas and Baltimore adopting it as mandatory with a few exemptions.

Conclusion

Other trends to keep an eye on in green and sustainable construction include:

Diversion of nonhazardous materials to landfills by recycling construction waste and deconstructing, rather than demolishing, buildings. This means waste that would otherwise end up in landfills gets recycled or reused in other building materials.
Reducing water usage by through rain harvesting and blackwater and greywater treatment systems.
Improving energy efficiency with things like cool roofs, green roofs, LED lighting, increased natural lighting and using low-emittance windows and glazing. Energy monitoring and management systems and advancements in heating and cooling systems such as displacement ventilation will all aid in reducing energy use in buildings.