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.