From net energy to zero energy buildings: Defining life cycle zero energy buildings (LC-ZEB)

• Published in: Energy and buildings Vol. 42; no. 6; pp. 815 - 821
• Main Authors: Hernandez, Patxi, Kenny, Paul
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.06.2010; Elsevier
• Subjects: Accounting; Applied sciences; Assessments; Bioclimatic building; Building components; Building life cycle; Building technical equipments; Buildings; Buildings. Public works; Ecological monitoring; Economics; Embodied energy; Energy management and energy conservation in building; Energy use; Environmental engineering; Exact sciences and technology; Life cycle energy analysis; Life cycle engineering; Net energy; Net-zero energy building; Types of buildings; Zero energy building; Zero energy building; Net-zero energy building; Building life cycle; Net energy; Embodied energy; Life cycle energy analysis; Energy analysis; Life cycle (environment); Zero energy house; Definition; Built environment; Optimization; Low energy building; Application; Net energy analysis
• ISSN: 0378-7788
• DOI: 10.1016/j.enbuild.2009.12.001

There are various definitions of ‘zero energy’ and ‘net-zero’ energy building. In most cases, the definitions refer only to the energy that is used in the operation of the building, ignoring the aspects of energy use related to the construction and delivery of the building and its components. On the other hand the concept of ‘net energy’ as used in the field of ecological economics, which does take into account the energy used during the production process of a commodity, is widely applied in fields such as renewable energy assessment. In this paper the concept of ‘net energy’ is introduced and applied within the built environment, based on a methodology accounting for the embodied energy of building components together with energy use in operation. A definition of life cycle zero energy buildings (LC-ZEB) is proposed, as well as the use of the net energy ratio (NER) as a factor to aid in building design with a life cycle perspective.