The implementation of energy efficiency improvements in facades, such as ventilated facades or External Thermal Insulation Composite Systems (ETICS), is leading to a widespread modification of these structures. The lack of appropriate regulations to curb the destruction of the built heritage, particularly in historical centers, has been identified. In response to this issue, a project has been developed to create a prototype for determining regulations for facade interventions. The Design Science Research Methodology (DSRM) has been employed in the development of the prototype, which has been tested in a case study of the ensemble formed by the Cortázar and Oriental expansion areas in San Sebastián. The initial prototype has been outlined, corrected, and improved in an iterative process, resulting in a final prototype that enables a faster, more rigorous, and efficient understanding, characterization, classification, study, and definition of intervention criteria, measuring the vulnerability of buildings to these interventions quantitatively. In this study, the vulnerability is defined as the risk that a facade will alter the characteristics of its architectural style and distort the reading of streetscapes that belong to a period with a clearly defined character. The case study results have been compiled into intervention criteria sheets for each of the studied buildings. This material has been presented to the relevant public authorities, with the hope that it may lead to a modification of current legislation, thereby helping to curb the loss of architectural heritage identity.

El fin del presente trabajo es analizar un conjunto de edificios fabriles situados a lo largo de una carretera, un ejemplo de paisaje industrial lineal, fenómeno característico de Gipuzkoa en la primera mitad del siglo xx. Se trata de realizar una reconstrucción gráfica de un grupo de edificaciones que se hallan en diferentes estados de conservación, pero que corren riesgo de desaparecer, y que han sido protegidos por su valor arquitectónico singular, pero no como conjunto arquitectónico y patrimonial. Se pretende implantar una metodología gráfica válida para la investigación y descripción de este tipo de paisajes lineales, que pueda ser reutilizada para el estudio de otros conjuntos patrimoniales similares.

Notable shortcomings and difficulties can be identified along the cultural-heritage value chain that can result in missed opportunities with respect to vulnerable cultural and architectural heritage, especially in the case of industrial architectural heritage. Shortcomings have been observed in the early documentation stage, which constitutes the foundation for subsequent processes. The objective of this article is to respond to this issue by presenting a research methodology for the documentation and analysis phase and demonstrate its application to an industrial architectural complex: “Nueva Cerámica de Orio.” This article describes the detailed study of the existing documentation through cross-referencing data from various sources. The application of this methodology facilitated the establishment of a general understanding of the heritage asset and its characteristic, providing a solid base for the development of the value chain.

Façades play a decisive role in shaping the visual and symbolic character of historic urban environments. Recent European funding schemes promoting energy-efficient retrofitting have accelerated interventions on building envelopes. Although aligned with decarbonization objectives, these processes are generating significant chromatic and material transformations that risk eroding the visual coherence and cultural sustainability of consolidated urban areas. In the historic Ensanches of San Sebastián, the replacement of traditional envelope systems with new cladding solutions is leading to the loss of the architectural style of some facades and altering their materials, textures, and colors. A progressive “contagion effect” has been identified, whereby dissonant chromatic schemes—often associated with the proliferation of so-called “zebra blocks”, residential buildings with façades clad in alternating black and white stripes that have proliferated in recent urban developments—are replicated across adjacent buildings, gradually weakening spatial continuity and the genius loci of the neighborhood. In response to this phenomenon, this research develops a systematic methodology to analyze, quantify, and anticipate chromatic transformation in consolidated urban fabrics. The study combines historical morphological analysis, classification of architectural periods, and chromatic mapping of recent façade interventions. Based on this framework, a CARI, Chromatic Alteration Risk Index is proposed to evaluate the potential impact of façade alterations on urban chromatic coherence. Drawing on an epidemiological framework, the methodology enables the identification of critical transformation clusters, the assessment of contagion dynamics, and the definition of regulatory thresholds for color and material interventions. By integrating perceptual criteria, urban morphology, and spatial distribution patterns, the study moves beyond descriptive diagnosis and offers a transferable tool for municipal planning. The proposed approach supports the proactive regulation of façade rehabilitation processes, balancing energy efficiency objectives with the preservation of collective memory, material identity, and urban sensory quality. This study proposes a quantitative model of “urban chromatic contagion” to assess how façade color interventions propagate within a neighborhood. We define the Chromatic Integration Percentage (CIP) and the Chromatic Alteration Risk Index (CARI) of the analyzed area. Results indicate that poorly regulated façades show higher chromatic dissonance (low CIP) and act as contagion hotspots, while a clear risk gradient emerges: highly protected buildings present lower risk, whereas mixed typologies and recent rehabilitations concentrate higher CARI values. The model supports preventive urban color management by identifying areas at risk before visible alteration.

La figura de Luis Tolosa destaca no sólo por su producciónarquitectónica, sino también por su obra gráfica. Fue el autor de algunas de las más destacadas obras de la arquitectura industrial guipuzcoana entre 1930 y 1950. Sinembargo, su faceta como dibujante es posiblemente más significativa, ya que supo manejar con maestría distintas técnicas gráficas adaptándolas a los objetivos de cada dibujo. Además, realizó una gran cantidad de perspectivas en las que demostró un excelente control del punto de vista y del encuadre, integrando el contexto geográfico por el que demostró un especial interés. El objetivo de este artículo es analizar su obra gráfica e identificar las principales características. Para ello, se han revisado sus dibujos y se han contrastado con los que aparecen en las revistas extranjeras que Luis Tolosa solía consultar. En definitiva, con este trabajo se pone en valor su faceta como excelente dibujante.