Under the climate change threat, the need to save energy and reduce CO2 emissions is currently a priority at European and global level, as stated in the signing of the European Green Pact.
According to official EU data, more than 40% of energy consumption is due to heating and cooling of dwellings. In addition, the construction process also represents a considerable energy expenditure related to the extraction, production and transport of building materials. Similarly, the actions of demolition and waste disposal in the phase of possible depreciation at the end of the life cycle represent an energy expenditure and an accumulation of waste.
Como es sabido, los edificios históricos de valor patrimonial son la base de nuestra historia, cultura e identidad. Muchos de estos edificios son viviendas aisladas o agrupadas en asentamientos rurales o centros históricos, y su rehabilitación es fundamental para la conservación de nuestra historia e identidad. Esta arquitectura patrimonial no sólo es importante como seña de identidad vinculada al paisaje donde nace, sino también es una fuente de lecciones de sostenibilidad. La conservación de la arquitectura vernácula, y de forma más amplia, de la arquitectura histórica y patrimonial, garantiza la preservación de la identidad material, cultural y popular, ofreciendo además una inspiración para la arquitectura contemporánea con ejemplos en sostenibilidad.
As is well known, historic buildings of heritage value are the basis of our history, culture and identity. Many of these buildings are isolated or clustered dwellings in rural settlements or historic centres, and their rehabilitation is essential for the preservation of our history and identity. This architectural heritage is not only important as a sign of identity linked to the landscape in which it was born, but also as a source of lessons about sustainability. The conservation of vernacular architecture, and more broadly, of historic and heritage architecture, ensures the preservation of material, cultural and popular identity, and also provides inspiration for contemporary architecture with examples of sustainability.
Therefore, the preservation of traditional architecture today faces two main concerns worldwide:
Improving energy efficiency in existing dwellings
Although there is a large literature on improving energy efficiency in building renovation, the vast majority focuses on housing built after the 1950s. Although these studies are of interest in measuring and quantifying energy efficiency in buildings, they have hardly been carried out on historic and heritage buildings that require the application of conservation criteria. Therefore, the notable differences between the rehabilitation of dwellings in the second half of the 20th century and the restoration and rehabilitation interventions of architectural heritage make it necessary to resort to other tools and guidelines used in the field of conservation.
At the same time, several studies confirm the energy efficient qualities of traditional architecture as a type of architecture adapted to the local environment and climate. Therefore, it could be argued that interventions to improve energy efficiency in historic and traditional buildings could be minimised, in addition to reducing their potential impact on heritage buildings. However, events such as floods or more intense rainfall resulting from climate change are putting this vernacular climate adaptation to the test, so that the adaptation of heritage to climate change is beginning to generate new needs, questions and reflections.
Reducing the carbon footprint during the life cycle of architecture
It is increasingly claimed that retrofitting, conservation, rehabilitation and adaptation of existing architecture are more environmentally sustainable processes than demolishing to build new architecture. Although there are a increasing number of guidelines and measures to prevent CO2 production as much as possible in the construction of buildings, in terms of the application of LCA to retrofitting processes, once again it is mostly concerned with dwellings dating from the mid-20th century, with very few cases of application of this assessment to heritage buildings. In the field of restoration and rehabilitation of heritage architecture, different intervention criteria involve the use of different types of traditional and industrial materials and techniques, and the impact on the environment can vary widely depending on the choices, techniques and materials adopted in the project.
The research group involved in this project has carried out a first analysis and measurement test in the specific case of a traditional house restored with traditional materials and techniques. It has demonstrated how this type of intervention reduces emissions by more than 50% compared to the use of industrial materials in a refurbishment and by more than 70% compared to the demolition and new construction of a new building.
Dissemination and raising public awareness
Moreover, the conservation of traditional housing heritage in both rural and urban contexts always causes misunderstandings and difficulties among all those involved in the process (owner, builder, designer, administration, etc.), given the lack of knowledge of traditional materials, techniques and processes and their possible updating. The assumption that the costs of a restoration with traditional materials and techniques are lower than those of a restoration with conventional materials often frightens the owners. However, previous work has demonstrated the economic validity of these interventions.
Currently, there are still very few examples of restoration of traditional architecture using traditional materials with the aim of preserving authenticity, and even fewer studies have clearly demonstrated the impact of these alternatives from the conservation project on CO2 emissions into the environment.
Finally, it should be noted that the phenomenon of depopulation is becoming increasingly serious both in Spain in general and in some inland regions of the Valencian Community. The rehabilitation of traditional dwellings in historic rural contexts or small urban centres can be a significant factor in slowing down the depopulation of rural areas. Rehabilitation in itself leads to the recovery of existing buildings as a first or second home and improves the conservation conditions of the population, creating a greater attraction for inland tourism. In addition, rehabilitation using local materials maintains or reactivates the local production of the materials and maintains or recovers the local trades that work with these materials.