September 13, 2018

10 Tips Architects and Builders use to Build a Net-Zero Energy Office Building

The Importance of Net-Zero Energy Buildings (NZEB)

Architects and commercial contractors that design and build net-zero energy buildings (NZEB), lead the way towards a green and sustainable country. NZEBs produce as much energy as they use annually.

Commercial buildings represent 19 percent of the energy consumption in the United States. Therefore, implementing NZEB methods in commercial buildings is crucial to combating rising energy prices and fossil fuel dependency. Improving energy-efficiency in commercial buildings is also critical to reducing carbon dioxide emissions, a known cause of global warming.

Architects and commercial contractors that build and design NZEBs are vital to decreasing the nation's energy consumption and creating a greener and more sustainable society.

The Whole-Building System Approach to NZEB

The whole-building systems approach aims to construct NZEBs that efficiently use natural resources and lessen waste. The building team (the architects, developers, engineers, builders, owners, and the building's occupants) is involved in all parts of the building’s design and construction.

The whole-building system approach treats an office building as one energy system in which each part impacts the efficiency of the entire building. During the design phase of a net-zero energy building, the building team works together to select construction materials, assemblies, and systems that minimize energy use and utilize renewable energy sources.

10 Tips for Achieving a Zero-Net Energy Office Building

1. A zero-net-energy office building must have a robust thermal building envelope with a continuous air and moisture barrier. The ASHRAE 90.1 and the 2015 IECC, in fact, require continuous insulation (CI) in many commercial structures.

Wrapping a building with a layer of CI, along with an air and moisture barrier increases the effectiveness of the building envelope and ensures a comfortable indoor environment. An excellent product that provides a high performing building envelope is the Bautex Wall System.

The Bautex Wall System creates energy-efficient exterior walls that contribute towards a zero-net-energy office building.

2. Site orientation (passive solar design) of an NZEB is critical for taking advantage of the sun’s energy. Specifically, in the Northern Hemisphere buildings should be oriented north-south. The north-south orientation minimizes direct sunlight during the summer (which reduces cooling demands) while maximizing sunlight during the winter (which lowers heating demands).

3. The windows of a ZNEB should make the most of natural light and control heat gains and losses. For example, windows that automatically darken when direct sunlight hits them (electrochromic and thermochromic) help control brightness, glare, and heat. Furthermore, shades and louvers on southern facing windows can assist in blocking out the heat in the summer and letting warmth in the winter.

4. A cool roof of an NZEB protects against solar heat gain and keeps the building cool. Denser materials like tiles, slate, or clay or materials that are reflective or have light colored pigments that reflect the sunlight are good cool roof products. Cool roofs improve indoor comfort of a commercial building and reduce energy bills.

5. The heating and cooling systems of commercial buildings account for 34 percent of a building’s energy use. The design of an energy-efficient commercial building should include high-efficiency heating and cooling systems that use less energy.

For example, the most efficient HVAC system is 95 percent efficient; meaning 5 percent of the energy produced is lost. It is imperative that  HVAC professionals install the systems in accordance with ENERGY STAR buildings. Improper installation of an HVAC can reduce the efficiency of a system by up to 30 percent.

6. Providing proper ventilation of an NZEB with an energy recovery ventilation system is essential because the air-tightness of an NZEB may trap pollutants (like radon, formaldehyde, and volatile organic compounds). An energy recovery ventilation system manages ventilation and lessens energy loss by transferring energy from conditioned air going out to fresh incoming air.

7. A commercial building’s office and computer equipment account for 6 percent of a building’s energy. The design of an NZEB must include ENERGY STAR®-labeled office equipment and electronics.

8. Lighting contributes up to 10 percent of a commercial building’s annual electricity costs and is a crucial design consideration of an NZEB. Controls such as timers, photocells that turn lights off when not in use, and dimmers can save energy and money.

Examples of energy-efficient lighting include light-emitting diodes (LEDs), compact fluorescent lamps (CFLs), and halogen incandescent.

9. The design of an NZEB should aim to create as much energy as it uses by installing renewable energy systems, like solar photovoltaic (PV) panels, wind system, small "hybrid" electric system, or microhydropower.

10. Connecting net-zero energy buildings to a traditional energy source (natural gas, electric, etc.) is advisable since the renewable energy generated cannot always meet the building’s energy loads. However, when the renewable energy exceeds the building energy requirements, the surplus energy can be transmitted back to the utility grid, which helps the building achieve the energy balance needed for an NZEB.

The Future of Net-Zero Energy Federal Buildings

In 2015, Executive Order (EO) 13693 introduced new Federal sustainability requirements and expanded upon requirements established by EO 13514, EO 13423, the Energy Policy Act of 2005 (EPAct 2005), and the Energy Independence and Security Act (EISA) of 2007.

Architects and builders interested in federal contracts should take note of Executive Order (EO) 13693. Executive Order 13693 requires federal buildings greater than 5,000 square feet to begin planning for net-zero buildings by FY 2020 or later. Also, federal buildings greater than 5,000 square feet must achieve net-zero energy (and water or waste net-zero, where feasible) by FY 2030.

The Whole-Building System Approach to Constructing an NZEB

Key to architects and builders achieving a net-zero energy office building is applying the whole-building systems approach. The whole building approach ensures that all members of building team work together to minimize energy use and utilizes renewable energy sources; with the ultimate goal of achieving a net-zero energy office building.

Constructing NZEBs is essential towards decreasing energy use, dependency on fossil fuels, and carbon dioxide emissions. Please visit Bautex™ Wall System for more tips on achieving net-zero energy office buildings.  

Adverse impacts of global warming include an increase in wildfires, rising sea levels,  more acidic oceans, and more frequent and severe weather events.


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