Net-Zero Energy Buildings: Key Features, Benefits, & Challenges

With an increasing emphasis on reducing energy consumption and finding ways to utilize renewable resources, net-zero energy buildings (NZEBs) have emerged as a promising solution to achieve maximum energy efficiency and sustainability in the construction industry. These buildings generate renewable energy and reduce energy consumption, resulting in zero net energy consumption. In this blog, we will explore the key features, benefits, and challenges of NZEBs.

In this blog, we will explore the key features, benefits, and challenges of NZEBs.

The Importance of Net-Zero Energy Buildings

NZEBs are structures that produce as much energy from renewable sources as they consume on an annual basis. This is important because it reduces the adverse impact on the environment from dependence on fossil fuels and saves the owner money over the life of the building.

NZEBs also reduce the total operational carbon output attributable to the building, both on site and at the utility power plant. This reduction in operational carbon output further enhances the environmental benefits of NZEBs by reducing greenhouse gas emissions, which contribute significantly to global warming.

In addition, these highly sustainable structures often offer improved airflow and natural daylight benefits, adding substantial value to the properties due to their efficiency and green building technology. All in all, NZEBs can save thousands of dollars in annual utility expenses while drastically reducing their overall environmental footprint.

How Do Net-Zero Energy Buildings Work?

NZEBs harness enough renewable sources, such as wind, solar and geothermal power, to produce all the energy required for day-to-day operations. To ensure optimal efficiency, engineers and architects evaluate factors such as climate and geography when constructing these innovative structures. For example, projects located in dryer climates exposed to intense sunlight will employ larger amounts of photovoltaic (solar) power systems than those of wetter regions with moderate temperatures.  Projects located in coastal or central plains regions typically experience more consistent, sustained wind velocities, resulting in shorter payback periods for wind-powered generator systems.  Other factors include mild climates that allow for passive heating and cooling designs, as well as the building site orientation, which impacts energy consumption in almost any climate.  Many NZEBs utilize passive heating/cooling techniques—such as natural ventilation, light shafts, and high performance insulation systems—in order to minimize energy consumption. Geothermal energy systems, like ground coupled heat pumps, also help to reduce the energy demands of a building, making it easier to achieve net-zero energy consumption at a lower overall price point.

Achieving net-zero energy consumption is really a two-step design process.  First, the building must be designed to utilize the most energy-efficient systems possible to reduce the amount of energy that is required to operate the building. Then, once the energy efficiency is maximized, the appropriate amount of local renewable energy sources, such as solar or wind power, can be designed to generate enough power to offset the total energy consumption of a building on an annual basis.  It is usually not practical to achieve instantaneous net-zero energy at all hours of the day and in all seasons.  Therefore, a NZEB is typically still connected to the utility grid. However, the key desired outcome is a net-zero energy consumption balanced across the entire year. 

Building owners stand to benefit financially in both the short and long term, since NZEBs are much more cost-effective to operate than utility company-dependent buildings, which rely heavily on non-renewable resources including fossil fuels.

With this smart technology leading the way to a more eco-friendly future, net-zero energy buildings have become both an attractive asset to sustainability initiatives and an important step towards a greener planet!

Challenges of Achieving Net-Zero Energy Buildings

Designing Net-Zero Energy Buildings

As stated previously, a net-zero energy building is a building that produces as much energy as it consumes on an annual basis. In order to achieve this, the building must be highly energy efficient and produce its own renewable energy.  Since the design of both the building and the renewable energy sources occurs before the building is built, it requires complex energy modeling software to ensure that the end goal is achieved once the building is constructed and operating.  Construction quality control becomes even more important, as shortcomings in the construction of the building can adversely impact energy consumption, resulting in a building that falls short of its net-zero goals.

While the concept of NZEBs is not new, the technology and knowledge needed to achieve this goal are now becoming more readily available and at a price point that makes sense for many building types.

The Cost of NZEBs

One of the biggest challenges facing the development of net-zero energy buildings is the cost. The technology and materials needed to make a building highly energy efficient are often more expensive than traditional construction methods.  Onsite renewable energy sources such as photovoltaics and wind power come at a high initial cost that must be amortized over the life of the building.  However, the cost of renewable energy sources can be partially offset by more efficient building design that results in lower capacity HVAC systems, saving money relative to a traditionally designed building.

Therefore, it is important to design the building to achieve net-zero energy consumption at the lowest possible initial cost, to ensure that it is economically viable to construct the building as planned.  Overshooting the net-zero energy goals can result in unnecessary upfront costs that could kill the project in its infancy, or result in cutbacks that jeopardize the overall sustainability objectives.   Prudent design, accurate calculations and tight construction quality control are essential to ensuring an economically viable NZEB design.

Finding the Right Location and Orientation

Another challenge associated with NZEBs is finding an appropriate geographic location, including both site selection and building orientation.  These factors are often ignored during the design process. However, properly sited and oriented, a building can substantially reduce its energy consumption, reducing both the cost of the building and reducing the cost of renewable sources to supply it with sufficient energy to reach net-zero.

In order for a building to be truly net-zero, it must be geographically located in an area with good access to sunlight and/or wind resources, or both.   Additionally, the site must also have enough space to accommodate the necessary renewable energy systems.  These may be located on the building, on the site or even utilized as shade structures for parking areas.   Again, creative and efficient design solutions lead to a cost-effective net energy facility.

Overcoming Barriers to Adoption

In addition to the challenges associated with the cost and location of NZEBs, there are also several barriers to their widespread adoption. One major barrier is the lack of awareness among consumers and builders about the benefits of these types of buildings.  Misgivings about the potential cost of a NZEB can often result in resistance to even investigating the possibility of achieving net-zero.  This is where the design team can be of particular value in educating owners.  The advent of quick and easy “shoe-box” energy modeling software can help architects and engineers present ideas for environmental sustainability initiatives very early in the design process, so these concepts can be presented to owners for consideration without the expenditure of large sums of time and money by the design professionals.  Once the sustainability objectives have been set, it is much easier to develop more detailed models and systems to achieve those objectives as the design progresses.

Creating a Business Case for NZEBs

One of the most important challenges facing those working to promote net-zero energy buildings is creating a business case for their adoption. Many decision-makers are reluctant to invest in these types of projects due to the high upfront costs and lack of familiarity with the technology.   It is important for the design team to investigate the availability and applicability of incentive programs offered at the federal, state and local levels, including both government programs and utility company programs, to help offset some of the upfront costs, making the business of sustainable design much more attractive to owners and investors.

Beyond the upfront costs, NZEBs often have dramatically lower operating costs than traditional buildings, making them a wise investment in the long run. Often, life cycle costs can be utilized to make the business case for sustainable design.

Conclusion

At Schnackel Engineers, we are deeply dedicated to responsible engineering and strive to create a more sustainable future for our clients and the planet. Our cost-efficient MEP engineering design services utilizing AI for MEP^TM technology can provide a viable path for creating energy-efficient buildings in which owners, investors and occupants can feel comfortable about their environmental impact.

By working together, we can reduce both initial costs and operating costs to make great strides toward gaining net-zero status, and ultimately create a healthier world for generations to come. We invite you to join us on this journey of sustainability!

Contact us today to learn more about our AI for MEP^TM technology applied to net-zero energy buildings and how they can contribute towards achieving true sustainability.