| Summary: |
The relative weight of the energy consumption of the existing buildings in the global energy consumption in the building sector is acquiring a preponderant and relevant role.
Such is mainly due to an increasing improvement in the quality of the new buildings envelope, by the generalized use of insulation, use of better glazing and use of several energy conservation techniques, resulting in less consuming buildings with significantly lower heating and cooling needs, when compared with the existing ones.
In Portugal there are 2 560 911 buildings built before 1990 (year of the publication of the first thermal performance building code) that represents 76.6% of the total number of the existing buildings. Due to the lack of thermal requirements and thermal concerns, these buildings appear as highly energy consumers when the purpose is to guarantee minimum comfort conditions. In this context, some forecasts point out that the buildings built up to 1990, will contribute, in 2050, with more than 80% of the global buildings energy consumptions, if any energy rehabilitations will not be made.
On the other hand, the degradation state of a huge part of the Portuguese building stock assumes proportions that can be considered alarming. This, causes a reduction on the populations quality of life and a deterioration of the built heritage, while collective memory. In the last years, Portugal, only invested about 13% of the total investment in conservation and rehabilitation of the built heritage, whereas the European Union average is of about 40%. In general, the country is not yet sensitive to the buildings rehabilitation necessity or importance, being always the new buildings more valued.
Additionally, the entrance into force of the new buildings energy performance regulations in Portugal, following the European Energy Performance of Buildings Directive (EPBD), will make mandatory the energy certification of new buildings and also of all the existing office buildings as wel  |
Summary
The relative weight of the energy consumption of the existing buildings in the global energy consumption in the building sector is acquiring a preponderant and relevant role.
Such is mainly due to an increasing improvement in the quality of the new buildings envelope, by the generalized use of insulation, use of better glazing and use of several energy conservation techniques, resulting in less consuming buildings with significantly lower heating and cooling needs, when compared with the existing ones.
In Portugal there are 2 560 911 buildings built before 1990 (year of the publication of the first thermal performance building code) that represents 76.6% of the total number of the existing buildings. Due to the lack of thermal requirements and thermal concerns, these buildings appear as highly energy consumers when the purpose is to guarantee minimum comfort conditions. In this context, some forecasts point out that the buildings built up to 1990, will contribute, in 2050, with more than 80% of the global buildings energy consumptions, if any energy rehabilitations will not be made.
On the other hand, the degradation state of a huge part of the Portuguese building stock assumes proportions that can be considered alarming. This, causes a reduction on the populations quality of life and a deterioration of the built heritage, while collective memory. In the last years, Portugal, only invested about 13% of the total investment in conservation and rehabilitation of the built heritage, whereas the European Union average is of about 40%. In general, the country is not yet sensitive to the buildings rehabilitation necessity or importance, being always the new buildings more valued.
Additionally, the entrance into force of the new buildings energy performance regulations in Portugal, following the European Energy Performance of Buildings Directive (EPBD), will make mandatory the energy certification of new buildings and also of all the existing office buildings as well as of the existing residential buildings, although, in this case, only in their selling or renting processes. This fact can transform the energy performance of the building into a determinant factor during its transaction, that is, the market will compel the execution of energy rehabilitation actions in order to increase the commercial value of the older buildings.
Currently the majority of the buildings rehabilitation interventions consists of isolated acts of substitution of materials and/or degraded components. This type of interventions results systematically in expensive interventions with few practical results in terms of energy consumption reduction, resulting also in long periods of amortization of the investment. This type of interventions can even lead to the creation of new problems as local condensations or overheating. Thus, only with well thought and integrated rehabilitation interventions, that enclose global measures with the effective purpose of reducing the energy needs and the maintenance costs, of increasing the security and the market value, as well as comfort and aesthetic, it will be possible to turn the rehabilitated buildings more attractive and competitive, in qualitative terms, when compared with the new buildings.
On the other hand, the rehabilitation sector can move forward with the application of prefabricated systems that integrate the new concepts, technologies and demands of this new construction world. |