THE PASSIVHAUS STANDARD IN THE MEDITERRANEAN CLIMATE: EVALUATION, COMPARISON AND PROFITABILITY

INTRODUCTION

One of the main environmental problems faced by the global community in the twenty-first century is unquestionably the reduction of greenhouse gas emissions ( Fuller and Crawford 2011). To face this challenge, the European Union (EU) has set the so-called 2020 Horizon as one of its main objectives: limiting the emission of greenhouse gas emissions by 20%, satisfying 20% of all energy needs through renewable sources, and improving energy efficiency by 20% ( The European Union 2012). The last projection forecast in 2012 by the European Environmental Agency (EEA) established that Spain was one of the countries in the EU furthest from reaching these objectives ( The European Union 2013). As a result, implementing measures devised to meet the 2020 objectives is currently a priority for the Spanish government.

In recent decades, the housing sector has played a decisive role in increasing global energy demands and greenhouse gas emissions ( Nejat et al. 2015). In 2014 Spain's housing sector's energy consumption needs represented 19% of total national consumption and 31% of the electricity demand ( IDAE 2013). Starting from the design phase, reduction in energy consumption per square meter has become a prerequisite for the majority of buildings ( Parameshwaran et al. 2012; Koo et al. 2014).

The importance and urgency exhibited by the EU housing sector in achieving the government objectives outlined in the 2020 Horizon have led the energy market to show a clear trend towards buildings with higher energy performance in the future ( Shimschar et al. 2011). Similarly, the success factor of energy efficiency initiatives will depend to a large degree on the method or the indicators used when measuring energy performance in each building ( Abu Bakar et al. 2015; Day and Gunderson 2015). As a result, selecting one energy evaluation methodology over another can be decisive in the path taken by Spain, change the current perception of the country, and increase Spain's standing within the EU.

Several studies ( Feist et al. 2005; Schnieders and Hermelink 2006; Mahdavi and Doppelbauer 2010; Mlakar and Strancar 2011; Hatt et al. 2012; Dahlstrøm et al. 2012; Dequaire 2012; Proietti et al. 2013; Ridley et al. 2013; Stoian et al. 2013; Moran et al. 2014; O'Kelly et al. 2014) indicate that the Passivhaus standard (PS) can be used as a highly effective tool in both limiting greenhouse gas emissions and increasing building energy efficiency.

Other studies ( Audenaert et al. 2008; Moeseke 2011; Allacker and De Troyer 2013; McLeod et al. 2013; Mlecnik 2013; Stephan et al. 2013) challenge the adoption of the PS because they consider other options within the energy market to be better from both environmental and financial perspectives. Nonetheless, the precursors to the PS claim that the benefits of the standard can be replicated in any part of the world through its use during the design phase ( Feist 2014; Passive House Institute 2010, 2015; Passipedia 2015).

The main objective of this study was to analyze the viability of using PS through the Passive House Planning Package (PHPP) tool in the Spanish housing sector, focusing on its use in the Mediterranean climate in the Province of Barcelona. To that end, we selected an isolated semidetached home, that exhibits the typical characteristics of current Spanish housing so that any possible deficiencies or virtues of adopting the PS are easily observable.

The study was conducted using 3 construction proposals (PC, P1, and P2); the initial proposal (PC) is defined by conventional construction technology, while the remaining 2 proposals (P1 and P2) offer different construction alternatives focused on optimization (window glass, the building envelope, and improved installations), enabling evaluation of the PS criteria compliance. To test the ease of obtaining PS compliance without the need for changing the architectural design of the project, the design and space distribution of the PC alternative remained the same for the P1 and P2 options.