Energy Renovation of Residential Buildings in Cold Mediterranean Zones Using Optimized Thermal Envelope Insulation Thicknesses: The Case of Spain

Abstract

The residential sector of the European Union consumes 27% of the final energy of the European Union, and approximately two-thirds of the existing dwellings in the European Union were built before 1980. For this reason, the European Union aims to transform the existing residential building stock into nearly zero-energy buildings by 2050 through energy renovation. The most effective method to achieve this goal is to increase the thermal insulation of opaque elements of the thermal envelope. This study aims to assess the energy, environmental and economic impacts of the energy renovation of the thermal envelopes that are typical of the existing multi-family buildings of the 26 provincial capitals in the cold climate zones of Spain. To achieve this goal, the insulation thickness to be added to the walls, roof and first floor framework is optimized by a life cycle cost analysis, and the existing building openings are replaced, thus minimizing both the total heating costs and the total heating and cooling costs. The study uses four thermal insulation materials for four different heating and cooling systems in 10 different models. The results obtained will be used to propose energy renovation solutions to achieve nearly zero-energy buildings both in Spain and in similar Mediterranean climate zones.

Energy Renovation of Residential Buildings in Hot and Temperate Mediterranean Zones Using Optimized Thermal Envelope Insulation Thicknesses: The Case of Spain

“…The methodology developed in this study is as follows: (i) Selection of Spanish cities with hot and temperate Mediterranean climate and identification of their combined climate zones, taking into account the current climate zones and the climate zones considered in the construction period of existing buildings ; (ii) Definition of the studied building with a thermal envelope that represents the main characteristics of the existing residential building stock; (iii) For the case studies, determination of the thermal insulation materials, heating and cooling systems, and costs; (iv) Evaluation of the optimum insulation thicknesses to be added to the walls, roof, and FFF to minimize the total heating costs, total cooling costs, and total heating and cooling costs using LCCA; (v) For each combined climate zone, selection of the energy renovation solutions that are expected to reach NZEBs, and if this is not possible, selection of the best solution from the economic point of view for each system; (vi) Evaluation of the heating and cooling energy demands of the selected energy renovation solutions by thermal simulation, with previously rounding up the optimum insulation thicknesses to commercial thicknesses; and (vii) Evaluation of the energy, environmental, and economic impacts and verification of the achievement of NZEBs. The methodology developed in [12] is improved in (iv) and (v).…”

“…Main studies that have determined the optimum insulation thickness using life cycle cost analysis (LCCA) and P 1 -P 2 method for residential buildings. The objective of this study is to assess the energy, environmental, and economic impacts of the energy renovation of the thermal envelope of existing residential buildings in hot and temperate climate zones in Spain, complementing the results in [12] conducted for cold climate zones in Spain. LCCA is used to assess the optimum insulation thickness to be added to the walls, roof, and first floor framework (FFF), and existing building openings are replaced.…”

“…The residential building studied is a multi-family housing block, and its existing thermal envelope has the main features of the thermal envelopes of the existing residential stock in the studied climate zones. This study improves and adapts the methodology developed in [12] to determine the energy renovation solutions that will achieve NZEBs. These solutions are thermally simulated to fill in the gap between LCCA estimates and reality.…”

Development and Performance Assessment of Prefabricated Insulation Elements for Deep Energy Renovation of Apartment Buildings

“…A highly insulated building envelope is an inevitable prerequisite for nZEB renovation in all climates. López-Ochoa [13] analyzed the energy, environmental, and economic impacts of the energy renovation of thermal envelopes and optimized the insulation thickness to be added to the walls, roofs, and first floor.…”

Erratum: López-Ochoa, et al. Energy Renovation of Residential Buildings in Cold Mediterranean Zones Using Optimized Thermal Envelope Insulation Thicknesses: The Case of Spain. Sustainability 2020, 12, 2287

“…The authors would like to make the following corrections about the published paper [1]. The changes are as follows:…”