A groundbreaking acoustic installation called Ecotonos has made its debut at Open Air Design 2025, running September 18-21 at BAM - Biblioteca degli Alberi in Milan. Created through a collaboration between acoustic specialists Slalom and architectural firm UNA/UNLESS, the site-specific installation represents a revolutionary approach to merging sound technology with ecological design and multispecies coexistence.
Designed by architect Giulia Foscari, founder of UNA/UNLESS, Ecotonos combines Slalom's acoustic expertise with a conceptual framework rooted in ecology, cinema, and environmental consciousness. Staged within the event's theme "Frames of Nature," the installation explores silence and listening as powerful tools for reconnecting urban environments with biodiversity. The project extends research from UNA/UNLESS's Voice of Commons project, which was presented at the Venice Architecture Biennale.
The installation served as a catalyst for an extensive cultural program featuring public conversations about design, cinema, and urban ecologies. Moderated by Francesca Molteni, these talks brought together designers, curators, actors, and musicians to explore the intersection of nature and culture. The opening event featured Giulia Foscari alongside prominent cultural figures including Rosita Celentano, Giampiero Judica, and Patrizia Sardo Marras, with additional contributions from Alida Catella of COIMA Image and Caterina Mosca of MoscaPartners. Additional sessions, including one led by renowned architect Michele De Lucchi, expanded discussions on the role of nature within contemporary urban environments. The program was complemented by three open-air screenings focused on architecture and design.
Slalom, established in 2012 by Elettra de Pellegrin, specializes in high-performance acoustic panels for commercial, cultural, and public environments. The company's approach centers on circular economy principles, utilizing post-consumer plastics transformed into PETfelt, along with wool, wood, and natural fibers. Every product is designed for durability, recyclability, and reusability, aligning with the 2030 Agenda and ESG principles. De Pellegrin's guiding concept of "Acoustethics" merges functional sound performance with tactile and visual refinement, a philosophy clearly embodied in the Ecotonos installation.
UNA/UNLESS, founded by Giulia Foscari, operates globally across cultural, residential, and product design projects, with an impressive portfolio that includes work for the Anish Kapoor Art Foundation and LAS Art Foundation. Running parallel to the practice, the UNLESS Foundation ETS advances interdisciplinary research on the Global Commons, notably through Antarctica-focused initiatives such as Antarctic Resolution. UNA/UNLESS's work is characterized by a belief in preservation as radical sustainability, a principle that anchors both the Voice of Commons and Ecotonos projects.
The Ecotonos installation appears as a fractured prism positioned in the center of the park, functioning as a sculptural threshold that divides the sensory experiences of the city and the natural environment. The installation derives its name from "ecotones," the transition zones between ecosystems where biodiversity typically concentrates most intensively. On one side, its diamond-like, reflective surface dematerializes the Milan skyline into ghostly mirages, while on the other side, it opens into a soft, honeycomb-like interior carved with cavities that recall a natural beehive structure.
This unique geometry serves a dual purpose: absorbing and modulating sound while dampening mechanical urban noise and amplifying subtle natural frequencies, from bee vibrations to the gentle rustling of leaves. The installation functions as an interspecies refuge, integrating plug-in components specifically designed to host seeds, create microhabitats, and provide water stations for insects and birds. These cellular components are designed not as mere decorative elements but as active spatial tools for actively supporting urban biodiversity.
Ecotonos reframes nature not as passive scenery but as an active protagonist in urban design, creating a micro-sanctuary that encourages visitors to slow down, listen attentively, and engage meaningfully with the more-than-human world. In this gesture, the work becomes a political threshold between extraction and care, proposing silence as a radical act of resistance against urban noise pollution. The dual orientation represents an architectural expression of the tensions that define our current age: extraction versus care, and blind growth versus radical listening.
The installation carries forward material research developed for Voice of Commons, which was presented by UNA/UNLESS as a Special Project of the 2025 Venice Architecture Biennale. At the Biennale, Carlo Scarpa's restored ticket office was transformed into a Planetary Embassy dedicated to the Global Commons, where Slalom and UNA/UNLESS experimented with innovative acoustic "Spikes" developed using space-inspired techniques. At BAM, these surfaces reappear in an evolved, sustainable form, inaugurating a new line of sound-absorbing products designed with recycled, regenerated, and natural materials—representing a significant move away from conventional petroleum-based polyurethane solutions.
Open Air Design 2025 adopts cinema as a conceptual backbone, a theme that resonates throughout the Ecotonos experience. The installation echoes Werner Herzog's documentary "Encounters at the End of the World," where the profound silence of Antarctica reveals otherwise imperceptible natural phenomena. Similarly, Ecotonos aims to suspend urban noise and cultivate a state of attentive stillness, where interspecies interactions gain unprecedented clarity. This cinematic sensibility transforms the installation into a narrative device—a frame through which the public can perceive new relationships between the city, nature, and sound. The project demonstrates how innovative design can create spaces that foster both environmental awareness and acoustic wellness in urban settings.
