Sustainable Cities and Society 17 (2015) 132–140 Contents lists available at ScienceDirect Sustainable Cities and Society journal h om epage: www.elsevier.com/locate/scs Energy efﬁciency optimization of new and existing ofﬁce buildings in Guanajuato, Mexico Danielle Griego a , Moncef Krarti a,∗ , Abel Hernandez-Guerrero b a Civil, Environmental, and Architectural Engineering Department, University of Colorado, ECOT 441, UCB 428, Boulder, CO 80309, USA b Mechanical Engineering Department, University of Guanajuato, Salamanca, Mexico a r t i c l e i n f o Article history: Available online 29 April 2015 Keywords: Energy efﬁciency measures (EEMs) Optimization Ofﬁce buildings a b s t r a c t Energy use attributed to buildings accounts for 19% of the total energy consumption in Mexico and is estimated to rapidly increase with future building development. Existing Mexican energy efﬁciency standards (NOM-ENER) are primarily developed through a component based approach where energy efﬁciency guidelines are outlined for individual pieces of equipment with no interactions between these components taken into consideration. In this paper, a holistic and integrative energy analysis approach is considered to improve energy efﬁciency of commercial ofﬁce buildings. Speciﬁcally, interactions between various energy efﬁciency measures are investigated for both existing and new construction ofﬁce build- ings in Salamanca, Guanajuato using detailed simulation and optimization procedures. The results from the optimization analysis indicate that the most cost-effective potential for energy conservation in both new and existing ofﬁces is achieved by reducing ofﬁce equipment loads and more efﬁcient lighting tech- nology and controls. Over 49% annual energy savings can be achieved cost-effectively for both retroﬁt and new construction commercial ofﬁce buildings. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction Building energy consumption in Mexico makes up nearly 19% of the nation’s total demand where 16% is from residential energy consumption while 3% is reported for commercial building energy consumption (SENER, 2010). However, various sources identify that a portion of the industrial energy consumption is actually from commercial building end use because the national utility company, Comision Federal de Electricidad (CFE) categorizes non-residential customers by voltage. Commercial buildings are categorized as low voltage, but several service-sector facilities including hospi- tals, hotels, schools, retail and restaurants are medium industry customers. Thus, energy consumption attributed to the commer- cial building sector is greatly underestimated due to lack of accurate survey of the building stock and its characteristics (Feng Lui, 2010). The results of the study presented in this paper provide some insights on the beneﬁts of integrated energy efﬁciency analysis for existing and new built environment for Mexico, an emerging industrialized country where commercial building development is rapidly expanding. ∗ Corresponding author. Tel.: +1 303 492 3389; fax: +1 303 492 7371. E-mail addresses: krarti@colorado.edu, Moncef.Krarti@colorado.edu (M. Krarti). The primary objective of the study presented in this paper is to utilize an integrative optimization methodology to determine the best set of energy efﬁciency measures for commercial buildings in one speciﬁc region in Mexico: Salamanca, Guanajuato. The integra- tive approach used in this study is outlined in Fig. 1. The ultimate goal of the study is to address each of the essential components to develop building energy efﬁciency codes: energy efﬁciency, market variability, available technology, construction costs, and policy enforcement (DOE Building Energy Code Program, 2010). The energy efﬁciency component is covered through detailed whole- building energy simulation analysis, while construction costs and market variability are incorporated through life cycle cost (LCC) analysis and associated sensitivity analyses. Available technology in Mexico is incorporated in the optimization analysis through the selection of appropriate energy efﬁciency measures (EEMs). Finally, the policy enforcement element is considered by selecting a prescriptive based approach for energy efﬁciency recommenda- tions. The current building energy efﬁciency codes and standards for commercial buildings in Mexico include prescriptive compliance and performance compliance. The prescriptive codes are primar- ily for equipment while the performance based approach is limited to exterior thermal insulation recommendations. The Prescriptive based approach for equipment and appliances have been very http://dx.doi.org/10.1016/j.scs.2015.04.008 2210-6707/© 2015 Elsevier Ltd. All rights reserved.