Retrofit de la construcción mediante paneles prefabricados: una reseña del estado del arte. Building Retrofit through prefabricated panels:an overview on the state of the art.Resumen-El objetivo principal de este paper es ofrecer una reseña del utilizo de sistemas de paneles prefabricados en el retrofit de edificios. El retrofit representa un punto focal de la eficiencia energética, considerando el gran numero de edificios existentes, privados y públicos, en Europa. La necesidad de intervención en este ámbito es enfatizada por las Directivas Europeas, y por la roadmap de Horizon 2020. Varias investigaciones y proyectos se centran en el tema de la prefabricación en el retrofit, enfatizando la importancia de esta estrategia. La reseña de el estado del arte muestra los diferentes enfoques de los paneles prefabricados: una clasificación critica de estos proyectos diferencia entre sistemas basados en grandes o pequeños paneles, sistemas de ampliación basados en paneles estructurales y sistemas parcialmente prefabricados. Esta clasificación es útil porque consiente posibles progresos en este campo, enfatizando los adventajas y desventajas de cada sistema. Los asuntos mas importantes son los de diseño, fabricación, transporte y instalación. Una reseña de estos asuntos es también provista, enfatizando los campos de innovación, y los posibles futuros desarrollos de la prefabricación en el retrofit de las construcciones.Palabras clave-Reconversión de edificios; paneles prefabricados; envolvente del edificio; adaptación energética. Abstract-The main aim of this paper is to provide an overview of the use of prefabricated panels in external building retrofitting. Building retrofit represents a pivotal point in terms of energy efficiency, connected to the great amount of existing buildings, both public and private, all around Europe. The need of intervention is underlined by different European Directives, as well as by Horizon 2020 roadmap. Many research works and projects are focusing on the theme of prefabrication in retrofit, stressing the importance of this strategy. The review of the state of the art shows several approaches in terms of prefabricated panels: a critical classification of these projects distinguish between systems based on large and small panels, systems for extensions based on structural panels, and partially prefabricated systems. The classification is useful as it can help in understanding further development of prefabricated panels, underlining the advantages and disadvantages of the systems. The main challenges are linked to design, fabrication, transport and installation. An overview of those issues is also provided, stressing the main innovation fields to be further investigated, and the possible future developments of prefabrication in building retrofit.

a b s t r a c tThe development of new construction solutions is fundamental to enhance the building stock energy performance, and thus promote sustainable development in the building sector. These solutions must be sensitive to both the energy performance and the environmental performance. The aim of the work presented in this paper is the energy performance evaluation of non-conventional envelope solutions that were applied in a test building built at the University of Minho's Azurém campus. The evaluation was carried out by means of data analysis of in situ measurements, and also the use of energy and daylighting simulation tools. Prior to the simulations it was necessary to calibrate the model and create a climatic data file representative of the real weather conditions. From this evaluation it was possible to assess the potentialities of different construction solutions. The non-conventional solution presented a similar energy performance but a better environmental performance than the conventional solution, due to the use of lower embodied energy materials. It was also proved that, with minor modifications, the non-conventional solution can produce a better energy performance than the conventional one, evidencing the potential of application of these solutions.