Ex Macello – Aria
Regenerating a former slaughterhouse complex


Architecture, Landscape Architecture


"ExMacello", former slaughterhouse complex in Italy, sits in the Calvairate district on the east edge of the city of Milan. The area was built at the beginning of the 20th century but, due to a progressive abandonment started in the 90's, it's currently in a state of ruin and decay. Nevertheless, the area is still populated by buildings of strong architectural, industrial and historical value. Therefore, ExMacello has been selected as one of the main sites for Reinventing Cities, a competition with the aim to regenerate and provide new visions for abandoned parts of the city. In collaboration with the developer REDO and several Italian practices and partners, Snøhetta’s proposal, Aria, won the competition in July 2021.

Technical details

Master Planning, Renovation & Expansion, Sustainability, Mixed Use, Residential, Workspace
Milano, Italia

Redo SGR


Stantec, Barreca & La Varra, Mpartner s.r.l.

15 hectares

Photo: Wolf Visualizing Architecture

Photo: Wolf Visualizing Architecture

Milan’s first Carbon Negative Area

The envisioned masterplan will become a new neighborhood tying together the current fractured urban fabric and connecting with the existing infrastructure of green areas. The sites will be injected with activities that inspire new ways of learning, growing, living, and working. Health and environment take a front seat through experimenting with innovative and collaborative methods. Seamlessly weaving cutting-edge technology, the area’s rich cultural and architectural heritage and a program for initiatives dedicated to citizens, Aria will become a neighborhood targeting environmental, social and economic sustainability.

Aria is set to be the Municipality of Milan’s first Carbon Negative Area. Aria also aims for LEED Gold level certifications for buildings on site and LEED for Cities and Communities: Plan & Design-certification for the masterplan. This achievements will be obtained with 3 core principles: the deployment of green as a device, the intelligent choice of materials and the innovative energy use. This last one will mainly consist of a district heating network of fifth generation and the construction of photovoltaic systems (36k m2) to give back clean energy to the neighborhood (Renewable Energy Communities) and therefore subtracting CO2 from the city.

The use of plants and natural system

The role of plants and natural systems in bringing benefits to the project area and reducing its environmental impacts will go beyond the usual and fundamental places such as parks, avenues and gardens, vegetable gardens, facades and roofs. The innovative use of plants and soil will purify indoors, phytoremediate and re-naturalize open areas, regulate and treat water, capture CO2, and filter out air pollutants. Existing and new buildings will leave green and nature at the center of the site, in a neighborhood that is reborn sustainable, resilient and with zero emissions.

Preserving the cultural and architectural heritage

Central to the proposal then is the regeneration of the industrial buildings, ensuring the preservation of the site’s rich cultural and architectural heritage and helping the environment through circularity of the buildings and materials. Reusing 30.700 m2 of existing buildings, the project eliminates need for over 4.500 m3 of reinforced concrete. This approach, combined with a design strategy focused on production, assembly and disassembly, allows Aria to reduce climate-altering emissions during construction by as much as 52% compared to the BAU (Business As Usual).

Photo: Wolf Visualizing Architecture

Promoting urban, social, and cultural biodiversity

This new part of the city will host a mixed-use development to include social and free market housing, offices, a university, a kindergarden, services for the neighborhood, a museum and commercial activity.

The adaptability of the human, social and environmental ecosystem is at the heart of the strategies implemented in the masterplan, including the ability to exploit the waiting time between the approval of the masterplan, the construction site, and its conclusion, to build an active community both around and within the site from the early stages of intervention. The aim will be to promote urban, social, and cultural biodiversity by exploiting design solutions, both temporary and definitive, accessible to different segments of the population not only as users of the offer, but also as co-producers of initiatives and owners of this new part of the city.

Photo: Wolf Visualizing Architecture