This paper addresses the effect of building orientation efficiency of the green facade in energy consumption, for which the case study is an urban block in Passeig de Gracia, L’Eixample, Barcelona. Nowadays, many countries are faced with the trouble of the deficiency of energy resources and the incapability of saving them. Most of this energy is consumed in the cooling, heating, and artificial ventilation of buildings. For this reason, the development of an integrated strategy like a green facade is essential to transform buildings into structures that consume less energy and to improve the occupants’ comfort conditions. From the perspective of the urban landscape, the green facade can influence the quality of life in cities due to its positive effects such as the purification of air, the absorption of carbon dioxide, and the mitigation of dust, as well as the aesthetic and psychological aspects. Such criteria are based on the adoption of suitable orientation for the green facade, which is the second layer of the facade in an office building with a curtain wall as the main facade. Since the most important factor in the implementation of a green facade is the building’s orientation, the optimum orientation could be the key factor in regards to the reduction of energy consumption and cost and the improvement of overall energy efficiency. We used software that helped simulate the total energy consumption, the cost, and the energy use intensity annually and monthly. Consequently, after testing was carried out, it was proven that a green facade as a second layer with a southeast and/or a southwest orientation results in the maximum energy saving in a coastal city with a Mediterranean climate like Barcelona.

The aim of this paper is to investigate the thermal performance of vertical gardens by comparing the thermal comfort of bare (glazed) and green façades in the Mediterranean climate. The proposal consists of applying a vegetation layer on a glazed façade that could control solar radiation and reduce indoor air temperatures. This study investigates the thermal performance of green façades of an office building in the Mediterranean climate. For this purpose, the Gas Natural Fenosa Office Building as a case study was simulated, that is located on a site next to the coastline in Barcelona. Dynamic building energy simulation was used to determine and assess indoor thermal conditions and, for this reason, the IES VE as a simulation tool has been utilized. Thermal comfort was assessed through the adaptive comfort approach and results were analyzed and presented in the terms of indoor comfort conditions during occupied hours. As a result, the article shows that applying a green façade as a vegetation layer caused a reduction in the internal and external façade surface temperatures, as well as the indoor air temperature of the workplace. Additionally, enhancing indoor comfort in summer is closely associated with reducing the external surface temperature. In winter, it also protects the exterior surface from the low temperature of the outside, and all of this greatly increases thermal comfort performance.

El desenvolupament urbà pot tenir un impacte profund en la salut i el benestar de les persones, la sostenibilitat de les ciutats, l'augment del consum d'energia a causa de l'augment de l'illa de calor urbana (UHI) i també el CO2, que és una de les preocupacions ambientals i socials. En aquest treball ha estat analitzat el jardí vertical com a segona pell a la façana, es comparen utilitzant diverses alternatives constructives de forma natural i sostenible. La proposta principal d'aquest estudi és una segona pell (façana verda) en un edifici d'oficines a Barcelona (Espanya) que es troba en orientació sud-oest, que té com a objectiu reduir al màxim el consum energètic i també millorar el paisatge urbà. Els jardins verticals, com a segona pell, s'implementen als murs exteriors de l'edifici per interceptar una quantitat de radiació solar cap a l'envolupant vertical de l'edifici. La metodologia es basa en l'avaluació de diverses opcions de façanes verdes mitjançant la simulació de les diferents mides de la profunditat, l'orientació i l'alçada de la cavitat de l'edifici. D'acord amb el resultat de la simulació obtingut d'Autodesk Green Building Studio, la profunditat de la cavitat de la façana verda com a segona pell és molt efectiva. La profunditat de cavitat s'ha de calcular segons allò especificat pel material de la façana principal de l'edifici i estructura, orientació de l'edifici, altura de l'edifici i clima. Aquest article presenta un cas d‟estudi que aplica aquest enfocament en un edifici d‟oficines ubicat a Passeig de Gràcia, zona de l'Eixample a Barcelona. Urban development can have a profound impact on the health and well-being of people, sustainability of cities, increasing energy consumption because of increasing urban heat island (UHI), and also CO2 which is one of the environmental and social concerns. The vertical garden as a second skin on the façade has been analyzed in this paper, are compared using several constructive alternatives in a natural and also sustainable way. The main proposal of this study is a second skin (green façade) in an office building in Barcelona that is located in southwest orientation, which aims to reduce energy consumption as much as possible and also improve the urban landscape. Vertical gardens as a second skin are implemented on the building's exterior walls to intercept a quantity of solar radiation towards the vertical building envelope. The methodology is based on the evaluation of various green facade options through simulation of the different sizes of the cavity’s depth, orientation, and height of the building. According to the result of the simulation obtained from Autodesk Green Building Studio, the cavity's depth of the green facade as a second skin is very effective in the performance of the green facade which cavity's depth must be calculated as specified by the building main facade's material and structure, building orientation, the height of the building, and also climate. This paper presents a case study that applies this approach in an office building located in Passeig de Gràcia, L’Eixample area in Barcelona, Spain. El desarrollo urbano puede tener un impacto profundo en la salud y el bienestar de las personas, la sostenibilidad de las ciudades, el aumento del consumo de energía debido al aumento de la ‘isla de calor urbano’ (UHI) y también el CO2, que es una de las preocupaciones ambientales y sociales. En este trabajo ha sido analizado el jardín vertical como segunda piel en la fachada, se comparan utilizando varias alternativas constructivas de forma natural y sostenible. La propuesta principal de este estudio es una segunda piel (fachada verde) en un edificio de oficinas en Barcelona (España) que se encuentra en orientación suroeste, que tiene como objetivo reducir al máximo el consumo energético y también mejorar el paisaje urbano. Los jardines verticales, como segunda piel, se implementan en los muros exteriores del edificio para interceptar una cantidad de radiación solar hacia la envolvente vertical del edificio. La metodología se basa en la evaluación de varias opciones de fachadas verdes mediante la simulación de los diferentes tamaños de la profundidad, orientación y altura de la cavidad del edificio. De acuerdo con el resultado de la simulación obtenido de Autodesk Green Building Studio, la profundidad de la cavidad de la fachada verde como segunda piel es muy efectiva. La profundidad de cavidad debe calcularse según lo especificado por el material de la fachada principal del edificio y estructura, orientación del edificio, altura del edificio y clima. Este artículo presenta un caso de estudio que aplica este enfoque en un edificio de oficinas ubicado en Passeig de Gràcia, zona del Eixample en Barcelona.

Purpose: This paper introduces a new type of biomimicry green façade system that integrates live cyanobacteria into a digitally generated architectural surface. The aim is to improve building envelope performance by combining natural biological processes with computational design. Design/methodology/approach: The study follows a three-phase methodology. Phase 1 establishes a generative design process, using Rhino and Grasshopper to create Voronoi-based geometries inspired by natural morphogenesis. A genetic algorithm filters variants based on solar gain, daylight autonomy and fabrication suitability. Phase 2 involves environmental simulation and optimisation using Ladybug and Galapagos, refining the design through solar, daylight and thermal performance metrics. Phase 3 embeds selected cyanobacteria strains into a bio-gel medium tested under controlled lab conditions to assess viability, photosynthetic response and integration feasibility. Findings: Simulation results demonstrate that the prototype significantly reduces peak solar gain (SHGC 50% above 300 lux) and enhances passive cooling through porous geometry. The embedded cyanobacteria show stable photosynthetic activity, enabling CO2 absorption and O2 release under appropriate light and hydration. Material testing confirms the feasibility of modular construction using recyclable substrates and hydrophobic coatings, while lab-scale trials show metabolic activity consistent with early-stage air purification potential. Comparative analysis shows the system's superiority in integrating biological and environmental performance in one responsive façade. Originality/value: This is the first façade prototype to integrate generative geometry, parametric environmental optimisation and living cyanobacteria within a functional, digitally fabricated system. Unlike existing biomimetic or algae façades, this design supports real-time metabolic interaction, enabling CO2/O2 exchange and adaptive performance. It establishes a new model for biologically active, performance-driven façades that contribute to environmental and urban resilience.