Commercial architects of NZEBs incorporate innovative technologies to decrease the nation's energy consumption and create a greener and more sustainable society. Net-zero-energy buildings (NZEBs) produce as much energy as they use, a financial, environmental, and quality of life win for everyone — and it's gaining popularity.

A 2018 energy-efficiency study reports that 61 percent of facility management leaders plan to have one or more nearly zero, net-zero, or positive energy/carbon status facilities within the next ten years. The passing of bills and energy codes by legislatures and executive orders further push us towards net-zero energy buildings. A ten-fold increase in NZEB construction shows no signs of slowing, expanding opportunities for green office building architects as they lead the way towards a sustainable country.

Why We Need Net-Zero Office Buildings

Commercial buildings represent 19 percent of the energy consumption in the U.S. Building commercial NZEB will save building owners and renters money and combat our dependency on fossil fuels. NZEB also helps reduce carbon dioxide emissions, a known cause of global warming and climate change.

Energy Codes and Standards Guide Net Zero Energy Architecture Design

Building codes help to guide architects in the design of energy-efficient, sustainable, and net-zero-energy buildings. In the U.S., architects can refer to the International Energy Conservation Code (IECC), used or adopted in 48 states, Puerto Rico, the District of Columbia, and the U.S. Virgin Islands. In Canada, architects can cite the National Energy Code for Buildings (NECB) and the National Building Code of Canada (NBC). In North America, the ASHRAE 90.1 and International Green Construction Code Adoption Map (IgCC), used or adopted in 14 states and the District of Columbia), provide architects significant guidance towards designing an NZEB.

10 Architectural Tips for Achieving a Net-Zero-Energy Office Building

Architects can achieve an NZE office building with innovative materials and methods. Please read on for Fox Blocks ten architectural tips for designing an NZE office building.

1. The Whole-Building System Approach

The whole-building system approach aims to construct NZEBs that efficiently use natural resources and reduce waste. It treats an office building as a single energy system, where each part impacts the entire building's efficiency. During the design phase of a net-zero energy building, the building team works together to select construction materials, assemblies, and systems that utilize renewable energy sources and minimize energy use.

The whole-building system’s success depends on all building team members, including the architects, developers, engineers, builders, owners, and the building's occupants participating in all parts of the building's design and construction.

2. Building Energy Modeling (BEM)

Building energy modeling (BEM) helps architects improve the building's energy efficiency and occupant comfort. BEMs use project-specific features like weather, building orientation, window location, building materials and methods, and more to predict/estimate a building's energy efficiency and demonstrate that it meets energy codes. The BEM can also help architects minimize construction costs at both the elemental and whole-building level. For example, a BEM can identify insulation levels required to achieve performance targets cost-effectively and offset an expensive, higher-quality envelope by requiring a less expensive, smaller HVAC.

3. Passive Solar Design

Passive solar design works with nature, resulting in lower energy bills. Specifically, an office building's orientation on its site and window placement should take advantage of the Sun's energy by maximizing or minimizing solar gains.

• A north-south orientation of the building minimizes direct sunlight during the summer (which lessens cooling demands) while maximizing daylight during the winter (which reduces heating demands).
• Maximizing windows on the south side of an office building takes advantage of the sunlight during the day. The windows also need overhangs, providing shade in the summer and sunlight in the winter. These windows further allow natural light to bathe the office space throughout the day, reducing artificial light's need and improving the workers' indoor environmental quality.
• Minimizing windows on the cold, shaded north parts of the building saves energy.
• To avoid solar heat gain and the glare from direct Sun, limit windows on the east and west side of a building.

4. ICF Above-Grade Walls

A zero-net-energy office building requires wrapping the entire building, including the above-grade walls, with a continuous (CI) layer and air and moisture barrier, as mandated by the ASHRAE 90.1 and the 2018 IECC, increasing the envelope's effectiveness ensuring a comfortable indoor environment. Fox Blocks insulated concrete forms (ICF) are a superior above-wall system for creating a high-performing, mass wall, building envelope of a net-zero-energy office building.

High thermal mass Fox Blocks ICFs, with an R-value of 23, produce a tight building envelope for an NZEB plus contribute thermal mass advantages. Simple to install, they prevent thermal bridging and the transfer of heat by conduction. Fox Blocks surpass ASHRAE/ANSI 90.1 energy code requirements for all climate zones. A Fox Blocks' solid monolithic concrete wall, with a perm rating less than 1.0, controls moisture intrusion and accumulation into the wall system, creating good indoor air quality and improving employee productivity.

5. ICF Below-Grade Walls

ICF foundations provide a superior design option for NZE office buildings. Uninsulated below-grade foundations account for up to 25 percent of a building's total energy loss.

Fox Block ICF foundations, along with a waterproofing product, provide durability and insulation to below-grade walls, stopping thermal bridging and lessening heat loss (R-value＞20) — contributing towards comfortable, healthy, and productive office spaces. An ICF foundation effectively resists cracking, lateral forces, buckling, and moisture intrusion — all of which can cause structurally damaging and unhealthy mold.

6. Cool and Insulated Roofs

A cool and insulated roof protects an office building against solar heat gains in the summer and keeps it warm in the winter, lengthening the roof's service life and improving indoor comfort and air quality. Dense roofing materials, like tiles, slate, or clay, reflect the sunlight with reflective or light-colored pigments.

High-performing roofing insulation reduces heat loss during the winter by 25 percent. It also limits moisture infiltration through the roof, preventing the growth of structurally damaging and unhealthy mold. Cool and insulated roofs reduce energy bills and improve an office building's indoor environmental quality.

7. Renewable Energy Systems

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

However, the design of an NZEB should connect to a traditional energy source (electric, natural gas, etc.) in case the generated renewable energy can’t meet the building's energy needs. Suppose a facility generates more energy than it uses. In that case, it can transmit the excess to the utility grid, helping the building achieve the energy balance needed.

8. Windows and Doors

About 20 percent of air infiltration occurs through cracks and holes in the windows, doors, and skylights in a building. Therefore, an NZE office building design should include ENERGY STAR® storm windows, doors, and skylights, improving the occupant's comfort and reducing heat loss by 25% to 50%. Installing automatically darkening windows (electrochromic and thermochromic) controls glare and brightness from direct sunlight. Louvers and shades can block out the summer's heat but will let the warmth in during the cold winter months.

Office buildings' with outdoor views and natural light improve workers' cognitive performance.

9. High-Efficiency HVAC and Ventilation Systems

An office building's heating and cooling system accounts for 34 percent of its energy use; therefore, an NZE office building should include high-efficiency heating and cooling systems that use less energy. For example, a 95 percent efficient HVAC system loses 5 percent of the energy it produces. HVAC professionals must install the systems per ENERGY STAR® specifications. Improper installation of an HVAC can lower the efficiency of a system by up to 30 percent.

An NZEB requires an energy recovery ventilation system because the air-tightness of an NZEB can trap pollutants (volatile organic compounds radon and formaldehyde). An energy recovery ventilation system also controls ventilation and reduces energy loss by transferring energy from outgoing conditioned air to fresh incoming air.

10. Lighting

Lighting contributes up to 10 percent of an office building's yearly electricity costs. To lessen energy use and costs, the design of an NZEB should include controls such as timers, photocells that turn lights off when not in use, and dimmers. Examples of energy-efficient lighting include light-emitting diodes (LEDs), compact fluorescent lamps (CFLs), and halogen incandescent.

Architects Can Achieve Net Zero Energy Building Design with Innovative Technology

Designing NZE office buildings requires architects to incorporate innovative materials and methods, like ICF construction, renewable energy sources, BEM, etc. A high-performing NZEB provides employees with a healthy, comfortable, and productive indoor environment, and saves money through reduced energy use and improved structural integrity. More and more business leaders plan to incorporate or construct NZEBs — a result of increasing public commitments and global initiatives for climate change and the need for carbon neutrality.

Please contact the professionals at Fox Blocks today to take the first steps in designing a net-zero-energy office building.