--Unfortunately, there is not a recipe for constructing a net zero energy building, but these guidelines provide a fundamental basis of how net zero energy is acheived through smart design and innovative technologies.

Alternative Energy Source

Alternative energy can come from a variety of sources: solar, wind, geothermal, and biomass.  These renewable energy sources can be harnessed in a variety of ways to provide power, heating, and cooling to a building and lower supplemental consumption by traditional grid utilities. The most influential factor in acheiving net zero energy in a building is choosing what type and how much alternative energy will be used.  Simply put, the alternative energy  source should be chosen based on the natural resources offered by the particular region of the world the building site is located.  A marine or coastal building site might consider wind while a tropical site might consider solar, and an inland moderate site may want to explore the local geothermal resources.  These are by no means strict guidelines for choosing a source but offer a logical basis of how to choose which source a feasibility analysis should be performed on.

In addition to an alternative energy source, other sustainable construction design, technologies and components must be used in order to further lower a building's demand of traditional grid utilities.

Passive Solar Design

One aspect of building design that has been around for hundreds of years but is very underconsidered is how the building will behave according to the sun.  Solar gain is responsible for heat gain that can drive the costs of cooling a building through the roof.  On the other hand the sun offers valuable natural light, and solar gain in the winter can help to heat a building.  Passive solar refers to a building's ability to naturally collect, store and distribute energy as needed according to a builing site's particular climate. 

Paying close attention to the building's orientation on the site, and window and door placement is essential to passive solar design.  In addition it is important to use components of a high performance building envelope, further reducing energy loads to create a net zero energy building. 

High Performance Building Envelope

Today, many building materials and technologies are designed to contribute to a building's ability to lower heating and cooling loads.  The concept of superinsulation is to make a building as air-tight as possible.  This can be done by adding multiple high performance insulations to a traditional structure, or by using panelized or site casted wall systems that eliminate thermal bridging while offering sound structural performance.  These non traditional wall structural systems are structural insulated panels (SIPs) and insulated concrete forms (ICFs).  Unfortunately, these panels can not alone be responsible for creating a superinsulated envelope as windows and doors will likely be present on everyside of the building.  The highest whole wall R-value is acheived by using SIPs and ICFs in combination with superinsulated doors and windows. 

Lighting and Daylighting

In commercial buildings, only one energy load is more demanding than heating and cooling individually.  That is the energy consumed by lighting.  In recent years, lighting products and systems have improved significantly to contribute to lower demands.  Of course, using no artificial lighting at all is the most beneficial to lowering consumption.  A typical net zero energy building will effectively allow daylight to penetrate deep into highly occupied spaces, and employ a high-tech sensored lighting system that adjusts artificial lighting output based on the amount of daylight present.  In addition, occupancy sensors can be used for areas that do not constantly need to be lit.  Of course, the artificial light source itself can draw less power when CFL adn LED bulbs are used.

Low Consumption Technology/Appliances

Other than lighting, additional electrical consumption comes from appliances and office equipment.  Fortunately, many manufacturers accross many industries have sustainability initiatives that focus on lowering the power consumed by their products.  Many rating systems such as the U.S. Government's Energy Star program make it simple for consumers to choose the right products that will help to acheive a net zero energy goal.