The objective of this paper is the environmental evaluation of two possible constructive solutions that improve the energy efficiency of existing buildings: replacement of the complete window with a new more efficient one or the use of solar control sheets attached to the current glass. A quantitative evaluation is proposed to help in the decision making to minimize the consumption of natural resources, energy incorporated in the materials, as well as its environmental impact, equivalent CO2 emissions. As an evaluation model, the methodology of the ARDITEC research group of the University of Seville has been adapted, in collaboration with the Higher Technical Institute of the University of Lisbon, applying to real projects in Portugal. The model has a budget structure where each resource is assigned coefficients for the calculation of its incorporated energy and carbon footprint, in its manufacture and commissioning. The study of two office buildings is presented, with a high percentage of glazed surface in facades. The results obtained show 70% lower emissions if the windows with attached films are improved compared to the complete replacement of the window. El objetivo de este artículo es la evaluación ambiental de dos posibles soluciones constructivas que mejoran la eficiencia energética de edificios existentes: sustitución de la ventana completa por una nueva más eficiente y uso de láminas de control solar adheridas a los vidrios actuales. Se propone una evaluación cuantitativa que ayude en la toma de decisiones para minimizar el consumo de recursos naturales, energía incorporada en los materiales, así como su impacto medioambiental, emisiones de CO2 equivalentes. Como modelo de evaluación, se ha adaptado la metodología del grupo de investigación ARDITEC de la Universidad de Sevilla, en colaboración con el Instituto Superior Técnico de la Universidad de Lisboa, aplicándose a proyectos reales en Portugal. El modelo tiene una estructura presupuestaria donde a cada recurso se le asignan coeficientes para el cálculo de su energía incorporada y huella de carbono, en su fabricación y puesta en obra. Se presenta el estudio de dos edificios de oficinas, con un alto porcentaje de superficie vidriada en fachadas. Los resultados obtenidos muestran emisiones inferiores en un 70% si se mejoran las ventanas con películas adheridas que si se opta por sustituirlas completamente.

Urbanization projects, understood as those supplying basic services for cities, such as drinking water, sewers, communication services, power, and lighting, are normally short-term extremely scattered actions, and it can be difficult to track their environmental impact. The present article’s main contribution is to employ the project budgets of public urbanization work to provide an instrument for environmental improvement, thereby helping public procurement, including sustainability criteria. Two urban projects in Seville, Spain are studied: the first substitutes existing services, and the second also includes gardens and playgrounds in the street margins. The methodology finds the construction elements that must be controlled in each project from the perspective of three indicators: carbon, water footprints, and embodied energy. The main impacts found are due to only four construction units: concrete, aggregates, asphalt, and ceramic pipes for the sewer system, that represent 70% or more of the total impact in all indicators studied. The public developer can focus procurement on those few elements in order to exert a lower impact and to significantly reduce the environmental burden of urbanization projects.

In Spain, 90% of companies are small- or medium-sized and are usually located in industrial areas, in warehouses with particular characteristics. This paper presents a methodology for the environmental assessment of this type of construction with water and carbon footprint indicators. A database was developed for the identification of typologies and common construction elements based on a sample of 87 projects in the province of Seville. Based on this, the paper proposes a methodology for comparative analysis that merges the data obtained from the research survey with environmental and economic data. The work proposes a systematic classification of the construction units of industrial buildings in order to improve the sustainability of the decision-making process by introducing environmental information on construction materials and machinery. First, the most impactful elements were identified, and then the technical solutions were adjusted using solutions already in the sample of 87 industrial projects. Reductions of up to 74% in the carbon footprint and 54% of the water footprint were found, as well as 14% reduction in construction costs in the most favorable case.

Dentro de los compromisos de la Agenda 2030, destacan los objetivos socioeconómicos para un desarrollo sostenible del conjunto de la sociedad, que plantean minimizar el impacto producido por la Administración Pública sobre el medio ambiente en todas sus actividades. Por ello, la creación y reforma de sus infraestructuras, necesarias para su funcionamiento y los servicios que presta, supone un gran impacto. El objetivo del presente trabajo se centra en una adaptación metodológica para evaluación ambiental de las obras promovidas por entes públicos, cuantificando y localizando los focos de impacto para poder tomar las medidas que los minimicen. Para ello, se proponen como indicadores la familia de las huellas, ecológica, de carbono e hídrica, caracterizadas por la simpleza del mensaje y la facilidad para implantarse en el sector de la construcción, a través del control de costes de los proyectos. En concreto, se presenta un estudio de caso, la construcción de un centro de educación infantil en la ciudad de Madrid, para cuyo análisis se exponen y analizan los datos necesarios. Los resultados reflejan información interesante, en términos de huellas, sobre los elementos que deben ser controlados y mejorados en el diseño del proyecto, tales como el hormigón y acero.