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By Micheel Wassouf – CEO Energiehaus Arquitectos. It may not be as intriguing as a police novel, but the acronym nZEB (Nearly Zero Energy Buildings) has captivated the world of construction in 2018, still leaving us to wonder how the film will pan out. Meanwhile, another key player, the Passivhaus standard, is becoming more and more prominent in Spain.

Public and private promoters, especially from the north of the country, are putting their chips on Passivhaus, seeing the maturity of its solutions around the world and the simplicity of the certification protocol itself. This year, strategic buildings such as the Towers of Bolueta (highest Passivhaus block in the world), the “carrer Nou2” building in Girona (first EnerPhit in multi-residential use), and the rehabilitation of an office building in Oviedo have just been certified under this standard.

What is Passivhaus?

Passivhaus must be understood as a construction protocol for buildings with almost zero energy consumption. It is a useful tool for architects, surveyors and engineers to control energy consumption and thermal comfort. Of course, it is not a guarantee of the quality of the architecture, this being the result of several complex vectors (urban development, history, functionality, energy, etc.). The ideal purpose of this standard is to find a balance between the traditional passive strategies around these parts (the Passivhaus) with the current advanced solutions (high tech). In other words, to combine good solar orientation, a sensible design of the openings, natural night cooling…, with very good thermal insulation, high quality windows, infiltration control and ventilation comfort. Only by taking into account this convergence of the past with the present is a building with nearly zero intelligent energy (nZEB) guaranteed. This convergence needs architects who are well-trained and who have a real interest in the energy vector. Passivhaus is not a matter of delegating the energy design to an external expert… it has to come from “the belly of an architect” (the title of a film by the English film-maker Peter Greenaway). Of course, you also need politicians, property developers, technical architects, engineers, builders and installers who are likewise highly trained and aware of the importance of the nEZB film.

Passivhaus Bolueta/ Bilbao – Developer Visesa, project/ PH-Design by VArquitectos, photo: VArquitectos.
Passivhaus calle Uria/ Oviedo – Developer “Calle Uría 58 Community of owners”, PH-Design Begoña Viejo, photo: T.Crespo/ Pevida.
EnerPhit paso a paso El Garrofer School – developer: Viladecans Municipal Council, project and PH-Design Energiehaus Architects/Berta Pujol, photo M.Wassouf.

Trends

The Zurich Cantonal Bank recently published a market study in which Passivhauses (in Switzerland: Minergie) are sold with a higher value of 3.5%, for multi-residential properties and, in the case of single-family homes, the higher value is 7% (see: https://www.minergie.ch/de/verstehen/uebersicht/). For this reason, the bank offers more attractive interest rates to developers who get on board with the Passivhauss (see: Umweltdarlehen zkb). Other private ethical banks are starting to offer similar products (for example Triodos). It will be only a matter of time before Spanish banks start copying the Swiss model. The first step was taken in the public sector by the municipal council of Villamediana de Iregua (La Rioja), which in its General Municipal Plan, has incorporated the obligation for all public buildings that are built in the municipality to meet the Passivhaus standard.

In turn, it also establishes that, from now on, 10% of homes built in new urban developments must comply with the Passivhaus standard. To do this, the buildability of this standard has been weighted with a coefficient that compensates for the additional cost that may be incurred by housing developers. Another prominent region committed to the Passivhaus is Navarre, whose regional government has committed to building 600 new rental homes to the Passivhaus standard, thus contributing to the mitigation of energy poverty in the region.

A Passivhaus type development not only means added value at the time of sale, it also offers the developer a privileged position in the public disclosure of the real estate. Of course, it should be accompanied with the official “Passivhaus” certification (or “EnerPhit” certification in the case of renovation), to give the building credibility on the market. We would point out that Passivhaus type development are starting to appear on the market not because of a quick return on investment, but rather due to a quality guarantee that sets out to satisfy users in terms of comfort, soundproofing and value for money (in the medium and long term).

The growing interest in the Passivhaus in social housing is also reflected in European research projects such as “Dreeam”, a project that seeks better access to financing building developments of this kind. The European “Revalue” project analyses the impact of energy efficiency on the financial evaluation of large-scale residential developments. Mexico stands out internationally thanks to a coherent policy of introducing the concept of energy efficiency in construction, defined since 2012 by “Nationally Appropriate Mitigation Action” (NAMA). This NAMA has the distinction of being the first to be applied in the housing sector at an international level. Since then, a series of national projects have been appearing and supported by international funds for the improvement of energy efficiency in homes. Numerous programmes (EcoCasa/NAMA Facility/LAIF/Renta/…) develop support mechanisms for the construction of sustainable housing (see for example: http://www.ecocasa.gob.mx/Paginas/Inicio.aspx), managed by several institutions, such as the public bank SHF (www.shf.gob.mx). Specifically, the objective of the LAIF project is to build a series of houses in Mexico to the Passivhaus standard, in the country’s various climatic zones. The construction of these buildings will send a very clear signal to other developing countries with warm climates, using the Passivhaus Standard as a proven strategy of ecological, economic and social sustainability policy. The housing prototypes designated to enter the EcoCasa LAIF programme are being built by the most innovative development companies in Mexico, as they are part of an open selection process among all the bidders in the country. They have undergone thorough controls by national and international experts throughout all phases of project design and execution, and monitoring is envisaged when residents have moved into these homes.

Passivhauss in Morelia/Mexico. Morelia has a very moderate climate (“Happy climate”), which allows the construction of Passivhauss with simple glass and without having to install a heat recovery system, photo M.Wassouf.

The future

The future of passive construction can be seen already in Central European countries; as is the case with the “Neue Heimat Tirol” in Austria. This is a public housing developer for rental homes, which is building housing blocks with a fixed rent of 5 Euros/m2 per month, including energy costs and VAT. Of course, these are Passivhaus buildings. This results in significant savings in management expenses. The flat rate is currently being debated in Central Europe. The latest trends propose the “budget” concept, combining the “flat rate” model with an incentive to save. The future European Passivhaus conference, which will take place in Heidelberg in May 2019, will surprise us with even more developments.