  Citation: Garzón-Juan, M.; Nieto-Morote, A.; Ruz-Vila, F. Review of NZEB Criteria: Design of Life Containers in Operations Area. Energies 2022, 15, 467. https:// doi.org/10.3390/en15020467 Academic Editors: Jose Ignacio Muñoz-Hernandez, Luis Baringo and Francesco Minichiello Received: 23 November 2021 Accepted: 7 January 2022 Published: 10 January 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Review Review of NZEB Criteria: Design of Life Containers in Operations Area Mario Garzón-Juan 1 , Ana Nieto-Morote 1, * and Francisco Ruz-Vila 2 1 Project Engineering Department, Polytechnic University of Cartagena, c/Dr. Fleming, s/n, 30202 Cartagena, Spain; mariogarzon@usal.es 2 Electrical Engineering Department, Polytechnic University of Cartagena, c/Dr. Fleming, s/n, 30202 Cartagena, Spain; paco.ruz@upct.es * Correspondence: ana.nieto@upct.es Abstract: The Spanish Ministry of Defense is currently attempting to reduce the amount of energy that is consumed by its military bases and has therefore raised concerns about how to make their facilities more energy efficient. To fulfill this objective, the Spanish army has developed various studies and projects, as well as a technical prescription sheet that defines the thermal transmittance values of the materials that are to be used to construct the different elements of the containers that make up the temporary housing units at Spanish military camps. Both governments and private entities have developed initiatives that are aimed at improving the energy efficiency of buildings, which are classified into two groups: those aimed at the development of mandatory building codes and those that are based on voluntary certification programs. The use of passive strategies is one of the key actions that is being implemented to achieve the NZEB category, as its first requirement is to be a “very low energy consumption building”. This paper compares the energy efficiency requirements of the tents and containers that are used in military camps and the energy-efficient design requirements that are demanded by the energy efficiency standards for buildings in the civil sector. Through this comparison, we determine how energy efficient the current living spaces in military camps are in order to define strategies that can be implemented to improve the design requirements of these living spaces so to reduce the consumption and operation logistics and to improve both operability and safety in military camp facilities. Keywords: design of life containers; NZEB; operations area; military camps; efficient design 1. Introduction: Evolution of Energy Efficiency in the Military Bases The development of the Paris Agreement at the United Nations Framework Conven- tion on Climate Change has resulted in the increased energy efficiency of buildings and the reduction of the GHG emissions of buildings, being one of the most important issues related to energy policy. Despite significant improvements in recent years, the global share of the final energy demand in buildings and the CO 2 emissions stood at 36% and 37%, respectively, in 2020 [1,2]. NZEBs (net-zero energy buildings) are regarded as an integrated solution that can be implemented to address problems that are related to energy-saving, environmental protection, and CO 2 emission reduction in buildings and in the construction sector. NZEBs mainly involve three kinds of energy efficient measures: passive design, service system, and power generation from RES, as shown in Figure 1. The use of passive strategies is one of the key actions that can be taken to achieve the NZEB category, since being a “very low energy consumption building” is the first requisite to achieve this status. Through these methods, a building’s energy consumption can be reduced by evaluating different passive strategies during the design stage and by implementing the most appropriate solutions according to the location, climate, cost, and available materials [3]. Energies 2022, 15, 467. https://doi.org/10.3390/en15020467 https://www.mdpi.com/journal/energies