Definitions
by Experts

Annual Electricity Consumption Gilijamse, 1995

‚ÄúA zero energy house is defined here as a house in which no fossil fuels are consumed, and the annual electricity consumption equals annual electricity production. Unlike the autarkic situation, the electricity grid acts as a virtual buffer with annually balanced delivers and returns.‚ÄĚ

Gilijamse, W. (1995). Zero-energy houses in the Netherlands. Proceedings of Building¬†Simulation ‚Äė95. Madison, Wisconsin, USA, August 14‚Äď16; 1995, pp. 276‚Äď283
Zero energy house


Annual Electricity Consumption Iqbal, 2003

‚ÄúZero energy home is the term used for a home that optimally combines commercially available renewable energy technology with the state of the art energy efficiency construction techniques. In a zero energy home no fossil fuels are consumed and its annual electricity consumption equals annual electricity production. A zero energy home may or may not be grid connected‚ÄĚ

Iqbal, M.T. (2003). A feasibility study of a zero energy home in Newfoundland. Renewable Energy Vol. 29, Issue 2 February 2004, pp. 277-289


Energy use Torcellini et al., 2006

‚ÄúA net zero energy building (ZEB) is a residential or commercial building with greatly reduced energy needs through efficiency gains such that the balance of energy needs can be supplied with renewable technologies.‚ÄĚ

Torcellini, P. & Crawley, D. (2006). Understanding Zero-Energy Buildings. ASHRAE Journal September 2006, Vol. 48 Issue 9, pp. 62-69


Exergy across District Boundary Kilkis, 2007

‚Äú‚Ķ a building, which has a total annual sum of zero exergy transfer across the building-district boundary in a district energy system, during all electric and any other transfer that is taking place in a certain period of time‚ÄĚ.

Kilkis, S. (2007). A new metric for net- zero carbon buildings. Proceedings of ES2007.
Energy Sustainability 2007, Long Beach, California, pp. 219-224


Scope Boundary Laustsen, 2008

‚ÄúZero Net Energy Buildings are buildings that over a year are neutral, meaning that they deliver as much energy to the supply grids as they use from the grids. Seen in these terms they do not need any fossil fuel for heating, cooling, lighting or other energy uses although they sometimes draw energy from the grid.‚ÄĚ

Laustsen, J. (2008). Energy Efficiency Requirements in Building Codes, Energy Efficiency Policies for New Buildings. International Energy Agency (IEA).
Building Codes


Off-grid NZEB Laustsen, 2008

‚ÄĚZero Stand Alone Buildings are buildings that do not require connection to the grid or only as a backup. Standalone buildings can autonomously supply themselves with energy, as they have the capacity to store energy for night-time or wintertime use.‚ÄĚ

Laustsen, J. (2008). Energy Efficiency Requirements in Building Codes, Energy Efficiency Policies for New Buildings. International Energy Agency (IEA).
Building Codes


On-Grid ZEB Gilijamse, 1995; Parker, et al., 2001; Iqbal, 2003; Laustsen, 2008

Laustsen, (2008): ‚ÄúZero Net Energy Buildings are buildings that over a year are neutral, meaning that they deliver as much energy to the supply grids as they use from the grids. Seen in these terms they do not need any fossil fuel for heating, cooling, lighting or other energy uses although they sometimes draw energy from the grid‚ÄĚ

Laustsen, J. (2008). Energy Efficiency Requirements in Building Codes, Energy Efficiency Policies for New Buildings. International Energy Agency (IEA).


Embodied energy Morbitzer, 2008

‚Äú‚Ķwhere possible, Bed ZED is built from natural, recycled or reclaimed materials. All the wood used has been approved to be sourced from sustainable resources, and construction materials were selected for their low embodied energy and were sourced within 35-mile radius of the site if possible.‚ÄĚ

Morbitzer, C. (2008). Low energy and sustainable housing in the UK and Germany. Open House International. Vol. 33, Issue 3, 2008, pp. 17-25


On-site supply Torcellini, et al., 2006

Use renewable energy sources available within the building’s footprint / PV, solar hot water, and wind located on the building.

Use renewable energy sources available at the site / PV, solar hot water, low-impact hydro, and wind located on-site, but not on the building.

Torcellini, P., Pless, S. & Deru, M. (2006). Zero Energy Buildings: A Critical Look at the Definition. National Renewable Energy Laboratory (NREL), USA
A Critical Look at the Definition

Torcellini, P. & Crawley, D. (2006).


Off-site supply Torcellini, et al., 2006

Use renewable energy sources available off site to generate energy on site. Biomass, wood pellets, ethanol, or biodiesel that can be imported from off site, or waste streams from on-site processes that can be used on-site to generate electricity and heat.

Purchase off-site renewable energy sources.

Utility-based wind, PV, emissions credits, or other ‚Äúgreen‚ÄĚ purchasing options. Hydroelectric is sometimes considered.

Torcellini, P., Pless, S. & Deru, M. (2006). Zero Energy Buildings: A Critical Look at the Definition. National Renewable Energy Laboratory (NREL), USA
A Critical Look at the Definition
Torcellini, P. & Crawley, D. (2006). Understanding Zero-Energy Build


Type of Renewable Energy Source

Esbensen, et al. 1977;¬†Saitoh, 1984; Saitoh, et al., 1985; Stahl, et al., 1995;¬†Voss, et al., 1996; Gilijamse, 1995;¬†Kramer, 2007; Mertz, et al., 2007; Parker, et al., 2001;¬†Rosta, et al. 2008; ‚ÄĚRiverdale NetZero Project-Edmonton, Alberta‚ÄĚ, 2008;¬†Noguchi, et al. 2008;¬†Charron, 2005;

Charron, (2005), gives a definition for zero energy solar homes: ‚ÄúHomes that utilise solar thermal and solar photovoltaic (PV) technologies to generate as much energy as their yearly load are referred to as net-Zero Energy Solar Homes (ZESH).‚ÄĚ

Esbensen, T.V. & Korsgaard, V. (1977). Dimensioning of the solar heating system in the zero energy house in Denmark. Solar Energy Vol. 19, Issue 2, 1977, pp. 195-199

Saitoh, T (1984). Natural energy autonomous house with underground water reservoir.

Bulletin of the JSME Vol. 27, Issue 226, April 1984, pp. 773-778

Saitoh, T., Matsuhashi, H. & Ono, T. (1985). An energy-independent house combining solar thermal and sky radiation energies. Solar Energy Vol. 35, Issue 6, 1985, pp. 541-547

Stahl, W., Voss, K. & Goetzberger, A. (1995). The self-sufficient solar house Freiburg.

Geliotekhnika Issue 1-3, January 1995, pp. 50-80

Voss, K., Goetzberger, A., Bopp, G., Häberle, A., Heinzel, A. & Lehmberg, H. (1996). The self-sufficient solar house in Freiburg РResults of 3 years of operation. Solar Energy Vol. 58, Issue 1-3, July 1996, pp. 17-23 

Kramer, J., Krothapalli, A. & Greska, B. (2007). The off-grid zero emission building.

Proceedings of the Energy Sustainability Conference 2007, 2007, pp. 573-580

Mertz, G.A., Raffio, G.S. & Kissock, K. (2007). Cost optimization of net-zero energy house.

Proceedings of ES2007. Energy Sustainability 2007, Long Beach, California, pp. 477-488

Parker, D.S., Thomas, M. & Merrigan, T. (2001). On the path to Zero Energy Homes.

Produced for the U.S. Department of Energy by the National Renewable Energy Laboratory, and DOE national laboratory
On the path of Zero energy homes

Rosta, S., Hurt, R., Boehm, R. & Hale, M.J. (2008). Performance of a zero-energy house.

Journal of Solar Energy Engineering, Transactions of the ASME Vol. 130, Issue 2, May 2008, pp. 0210061-0210064

Noguchi, M., Athienitis, A., Delisle, V., Ayoub, J. & Berneche, B. (2008). Net Zero Energy¬†Homes of the Future: A Case Study of the √ČcoTerraTM House in Canada. Presented¬†at the Renewable Energy Congress, Glasgow, Scotland, July 2008
CanmetENERGY

Charron, R. (2008). A review of design processes for low energy solar homes. Open House International Vol. 33, Issue 3, 2008, pp. 7-16


Disclaimer: This website is made possible by the support of the American People through the United States Agency for International Development (USAID). The contents of this website are the sole responsibility of Environmental Design Solutions and do not necessarily reflect the views of USAID or the United States Government.