The goal of our study was to determine whether renters and owners prefer ‘green’ residential buildings and if so, whether energy efficiency certification or availability of solar PV system and energy storage added to consumer value. We investigated which energy efficiency certification schemes were most widely recognized, whether the consumers supported mandatory certification, and through which channels information about energy efficiency certification was obtained. The data were gathered in January-February 2016 by means of a representative web survey with 1,001 respondents, residing in German- and French-speaking parts of Switzerland. Methodologically, this research is based on analysis of stated preferences and choice-based conjoint (CBC) experiments. CBC is a popular method in market research, because it mirrors a realistic decision situation, requiring respondents to make trade-offs among desired product features. The respondents were asked to choose among four potential properties for rent or purchase. Each property was described with respect to its location, number of bedrooms, quality of interior fittings, and price premium. The property description contained two ‘green’ features: energy efficiency rating ranging from A (best) to F (worst) and presence of rooftop solar PV system with or without half- or full-day battery storage. Each respondent answered ten randomly generated choice tasks, and observing these choices allowed us to indirectly measure consumer preferences. As expected, traditional property characteristics such as location, size, interior fitting, and price premium were the most important for determining property choices (joint relative importance of 71.5%). The relative importance of the two ‘green’ features accounted for the remaining 28.5%, suggesting that customers place nontrivial value on ‘green’ building characteristics. In particular, the respondents were interested in combining a solar PV system with a half- or full-day battery storage. This finding indicates the potential for marketing solar home systems together with storage solutions as part of modern, high-performance residential buildings. Furthermore, higher energy efficiency ratings (A or B) were strongly preferred to lower ratings (D or F). Our survey showed that 59% of all respondents favored the idea of mandatory energy efficiency certification for residential properties at the time of purchase. Support for mandatory certification was higher among renters (66%) than among owners (50%). The most widely known energy efficiency standard in Switzerland was the independent third-party certification scheme Minergie (known to 93% of respondents). GEAK certification, launched in 2009 by Swiss cantons, was known to 29% of respondents, followed by LEED (known to 27% of respondents), which is popular in North America. The respondents obtained information about energy efficiency standards from the media, such as magazines (48%), internet (37%), TV (33%), or radio (21%). Other important sources of information were friends and family (35%), property owners’ or renters’ associations (22%) and architects (16%). Compared to household appliances and cars, energy efficiency certification in the building sector still has untapped potential. While only a third of respondents took into account energy efficiency when buying a house, a large majority of respondents considered an energy label when purchasing household devices.

Anna Ebers, Rolf Wüstenhagen

Oct 2017