Research on the Portuguese Building Stock and Its Impacts on Energy Consumption – An Average U-Value Approach

Sousa, Jorge Freire de; Bragança, L.; Almeida, Manuela; Silva, P.

doi:10.2478/ace-2013-0029

Cited by 17 publications

(9 citation statements)

References 17 publications

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“…For the roof, walls, floor and windows, these average U-values are significantly superior to the reference U-values defined in the latest regulation, which is to be expected, as the first residential building energy performance regulation to be implemented in the country was the Buildings' Thermal Behaviour Characteristics regulation, in 1990. Although the average values have been decreasing in recent decades (Sousa et al 2013), Portugal, alongside Spain, has still registered consistently higher weighted mean U-values across building typologies for windows, pavement, walls and roofs, in comparison to the majority of European countries. The building characteristics vary across the EU-in northern countries, the dwelling stock has better and more insulation (and lower U-values), in response to the colder climate.…”

Section: Resultsmentioning

confidence: 95%

Harvesting big data from residential building energy performance certificates: retrofitting and climate change mitigation insights at a regional scale

Gouveia

Palma

2019

Environ. Res. Lett.

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The reduction of energy consumption and the increase in energy efficiency is currently an important cornerstone of EU policy. Energy performance certificates (EPCs) were implemented as one of the tools to promote this agenda, and are used for the energy performance assessment of buildings. In this study, the characteristics of the Portuguese dwelling stock are regionally analysed using data from approximately 523,000 Portuguese residential EPCs. Furthermore, a bottom-up building typology approach is used to assess the regional energy needs impact of retrofitting actions and to estimate the heating and cooling energy performance gaps of the whole dwelling stock, as well as the potential CO 2 emissions resulting from the gaps' potential offset due to increase thermal comfort. The results show that Portuguese residential buildings have very low energy performance, with windows and roofs being identified as the most energy inefficient elements. Roof retrofitting has the highest potential for the reduction of energy needs. The estimated heating and cooling energy performance gap amount to very significant percentages, due to the poor performing building stock but also very low energy consumption levels, with probable consequences for the thermal comfort of occupants. Assuming the current energy mix, carbon emissions would be 9.8 and 20.2 times higher associated with heating and cooling, respectively, if the actual final energy consumption were to match the estimated theoretical values derived from building regulation. This study demonstrates several application cases and leverages the potential of the individual EPC, increasing the detail in the dwelling stock characterization and energy performance estimation, revealing its value for energy retrofit and climate change mitigation assessments, as well as establishing the ground for future work related to building retrofits, energy efficiency measure implementation, climate change mitigation, thermal comfort, and energy poverty studies.

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Section: Resultsmentioning

confidence: 95%

Harvesting big data from residential building energy performance certificates: retrofitting and climate change mitigation insights at a regional scale

Gouveia

Palma

2019

Environ. Res. Lett.

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“…[22] the majority of the Portuguese multi-family buildings built between 1971 and 1980 have reinforced concrete structures (54.15%), rendered and painted façade (88%), and pitched roofs with ceramic tiles (93.4%). The construction data of the Portuguese buildings are obtained from an official report on the thermal performance of buildings and the application of the Portuguese building thermal regulation [52] and contrasted with other sources [27,53,54]. For the case of Spain the data from the TABULA EPISCOPE project [55] is used.…”

Section: Typical Residential Building To Be Renovated In Portugal and Spainmentioning

confidence: 99%

“…Las-Heras-Casas [26] studied the energy performance certificates in a region of Spain (Aragón), and found that the buildings erected between 1961 and 1980 have a 33.19% higher primary energy consumption and a 44.47% higher CO 2 emissions than those built after 2007. Sousa et al [27] studied the constructive solutions and energy performance of Portuguese buildings, and argue that buildings erected during the 60's, 70's and 80's are the ones with highest energy saving potential. Magalhães and Leal [28] studied the energy performance certificates of residential buildings in Portugal, and found that buildings erected before 1980 have higher levels of nominal heating energy needs.…”

Section: Introductionmentioning

confidence: 99%

The nZEB concept and its requirements for residential buildings renovation in Southern Europe: The case of multi-family buildings from 1961 to 1980 in Portugal and Spain

Monzón-Chavarrías

López-Mesa

Resende

et al. 2021

Journal of Building Engineering

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Southern Europe has an old housing stock and has the challenge, as the rest of European Union Member States, to transform it into a decarbonized one, by means of transforming the existing buildings into Nearly Zero Energy Buildings (nZEB). Member States have a large margin of discretion when defining the requirements for nZEB.In this paper, the nZEB requirements for the renovation of residential buildings in Portugal and Spain are studied in detail (unlike the usual more general comparative studies) for a specific building typology with poor energy performance. This is done by checking whether an existing residential building, renovated with different combinations of improvements of the envelope and active systems in two comparable cities in each of these two countries, fulfills the requirements or not, and by comparing the results of CO 2 emissions reductions. One of the improvements of the envelope considered are those necessary to fulfill the compulsory major renovation requirements in both countries to check how much we are already approaching to the decarbonization of the residential sector.The results show that nZEB standards applied to the renovation of typical multi-family buildings of 1961-1980 in both countries will significantly contribute to the descarbonization of the building stock for this type of building typology, with reductions of 80-96% of CO 2 emissions for Portugal and 71-94% for Spain, if they are applied. However, some aspects of the regulations could possibly be improved such as more restrictive requirements for the current regulations for major renovations in Portugal or the way energy from renewable sources is ensured in Spain, among others.

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“…It is representative of most of the common characteristics from Portuguese residential buildings built during the 1970s [80,81] in terms of: thermal resistance of the envelope elements (no insulation); construction materials (brick wall, sloped roof with ceramic tile, prestressed slab and wooden frame windows); typology (3-bedroom) and floor area (less than 100 m 2 ). Since the first Portuguese thermal regulation was only introduced in 1990 [82], the dwelling has no insulation materials, creating a need for improving the thermal behaviour of the building envelope. The dwelling total net floor area is 74.92 m 2 , the interior floor to ceiling height is 3.05 m and the glazed area is 6.3 m 2 .…”

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confidence: 99%

BIM-Based Energy Analysis and Sustainability Assessment—Application to Portuguese Buildings

et al. 2021

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Buildings are responsible for several negative impacts on the environment, most of them related to nonrenewable energy consumption, increasing the concern regarding buildings energy efficiency. In this context, computer software has been used to estimate the energy needs of the built environment, and the Building Information Modelling (BIM) methodology can be used to simplify this process. This study aims to validate a BIM-based framework to streamline the energy analysis of Portuguese buildings, based on the method of the national regulation for the thermal performance of residential buildings. Currently, designers need to spend considerable time assessing all the building characteristics and performing the mandatory calculations for energy performance analysis. It is also intended to link the results of the energy simulation with a Building Sustainability Assessment method—SBToolPT-H. The purpose is to demonstrate how it is possible to benefit from this approach to simultaneously improve building sustainability during the design stage. To do so, different case studies were modelled in Autodesk Revit and exported to a BIM energy tool to perform energy simulation analysis. The results were validated against the official assessment method of the Portuguese thermal regulation and were successfully used to assess the SBToolPT-H energy efficiency category. The research outcomes provide design teams with a reliable BIM-based framework to improve building energy performance and to develop thermal projects while enhancing building sustainability. It also increases the knowledge about the integration of sustainability assessment in the BIM environment, providing new insights for complete integration.

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Research on the Portuguese Building Stock and Its Impacts on Energy Consumption – An Average U-Value Approach

Cited by 17 publications

References 17 publications

Harvesting big data from residential building energy performance certificates: retrofitting and climate change mitigation insights at a regional scale

Harvesting big data from residential building energy performance certificates: retrofitting and climate change mitigation insights at a regional scale

The nZEB concept and its requirements for residential buildings renovation in Southern Europe: The case of multi-family buildings from 1961 to 1980 in Portugal and Spain

BIM-Based Energy Analysis and Sustainability Assessment—Application to Portuguese Buildings

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