Technical Considerations in a Zero Energy Home
Authors: Small Dorothy S. 
Published: June 2009

Building a zero energy home requires several major considerations: site selection for the home; considerations to use less; conservation of what you produce; and evaluation the best choices of renewable resources. This paper discusses the use of climate data collection software, heat loss and heat gain considerations and software; how to achieve a zero energy building and qualifying as a LEED (Leadership in Energy and Environmental Design) Certified Platinum home. Site selection is the first step. This first step can be taken after you have identified your goals. What alternative energy systems do you want to use? Do you want to use more than one alternative source? What other site considerations are important? In my case, I wanted to use solar energy as my primary alternative energy source. Why? I want comfort, reliability and ease of use. Other alternatives may require more maintenance. Wind power will be a second source that will be incorporated to produce electricity when the PV system can not produce. The site selected is a south facing mountain that has a steady breeze most of the time. Another consideration for me is the ability to use earth-sheltering as a measure of high efficiency construction. The south-facing mountain also provides the opportunity to “nestle” into the mountainside. Calculations and basis of design are presented. Using less is a key mindset that we all need to move toward. Using less does not mean that you suffer. This house will be comfortable year round with little effort because the house uses passive solar design for lighting and space heating, active solar hot water for additional heating of the floor and domestic hot water, and PV/wind/biodiesel generator backup to generate electricity for lighting and other typical electrical loads. The construction materials provide high R-values and green products that contribute to excellent indoor air quality. SIPs (Structural Insulated Panels) will be used as the structural components for the walls and roof. All electrical appliances, refrigerator, lighting, and washer/dryer were selected to use less electricity and water. Data describing the energy requirements are provided. Reuse all that you can. I am incorporating a masonry heater, also known as a Russian Fireplace. The combustion efficiency of the masonry fireplace is typically 92–94 percent with very low emissions. The masonry fireplace will provide passive mass for passive release of the woodburning energy during the evening and heat hot water coils in the fireplace as well (as the hot water backup system). The use of hard woods from the land will provide heat overnight, heat for cooking and supply additional BTUs for domestic hot water and radiant heat. Many of the building materials that are selected for construction are from the land; stone and whole cut wood from the land will be used for esthetic appeal and thermal mass thereby reducing harmful manufacturer’s emissions. My site is an excellent site for a hybrid solar and wind power (with a biodiesel generator as backup) system. The orientation and wind profile of the land is optimal for solar and wind energy applications. Site specific data and optimization of active solar, passive solar and PV/wind systems are presented. Life cycle costs are presented to show the cost comparison using Years-to-Payback and Return on Investment approaches for the energy systems and LEED certification costs for new construction.