Green, but not too wild: Applying a discrete choice experiment to reveal which dose of nature optimizes human benefits in living façade design

Urban greening through Nature-based Solutions (NbS) is increasingly promoted to mitigate the ecological and social costs of urbanization, yet little is known about public preferences for biodiversity-rich designs. This study investigates how residents perceive ecolopes, living building envelopes such as living façades, by applying a hybrid discrete choice experiment (DCE) with a representative sample of 723 Israeli respondents. Participants evaluated alternatives varying in vegetation cover, plant richness, and presence of animals, while attitudinal measures, nature relatedness, familiarity with living façades, and priming on ecosystem services were integrated into the model. Results reveal that respondents generally preferred façades with greenery over standard buildings, but acceptance was non-linear: medium vegetation cover was most valued, while both low and very high cover reduced willingness to pay. Plant richness had no significant effect, whereas the presence of animals consistently decreased acceptance, with mammals evoking the strongest negative response. Importantly, stronger nature relatedness, prior familiarity with living façades, and exposure to positive framing increased acceptance, partially offsetting biophobic tendencies. These findings underscore the need to balance ecological ambition with social acceptability in designing urban NbS. By aligning biodiversity goals with public preferences, medium-complexity designs can serve as an effective entry point for mainstreaming living façades, paving the way toward more nature-inclusive and resilient cities.