Inaugurated in March 2025, the Nuova Tore Est and Nuova Torre Ouest office towers now frame the entrance to the massive Porta Nuova urban renewal project in Milan, Italy. The towers’ foundations and all below-grade concrete structures were waterproofed with PENETRON ADMIX, a crystalline waterproofing admixture, to ensure durability.
Spanning 30 ha (72 acres) in the northern part of Milan, Italy, between the Central Railway Station and Garibaldi Station, the Porta Nuova is an urban renewal project that has transformed the former Varese train station and railroad yard into a pedestrian area with twelve residential and commercial buildings – varying in height – stretching from Piazza della Repubblica to Via Melchiorre Gioia. With two new public squares, extensive green spaces, and bicycle paths, the project masterplan also comprises office and residential space, as well as shops, restaurants, cafés, and a cultural center, all connected to Milan’s public transportation network. The Porta Nuova project was awarded the LEED for Cities and Communities and WELL Community sustainability certifications – a world first!
Designed by ACPV Architects (Antonio Citterio – Patricia Viel), the Gioia 20 East and the Gioia 20 West office towers frame the Via Melchiorre Gioia on both sides, filling the last remaining empty lots along this central avenue of the Porta Nuova development. The Gioia 20 East tower (height: 98 m/324 feet) with 23 floors, and the Gioia 20 West tower (64 m/212 feet) with 12 floors, offer a total of 38,000 m2 of office space. Retail spaces for shops and restaurants are located on the ground floors.
The outer shell of the towers is a very visible and key part of the LEED certification awarded to the project. A system of >2,000 integrated photovoltaic panels make up the exterior “skin” of the buildings, which generate an annual yield of 850,000 kWh – and reduce overall energy consumption of the towers by 60%.
“The construction site is situated in the Po Valley just south of the alpine lakes of Northern Italy,” adds Enricomaria Gastaldo Brac, CEO & Managing Director of Penetron Italia. “Because of the 20 m (66 feet) excavation depth needed to accommodate the underground parking garage and basement levels of the towers, groundwater was an issue.”
To protect the below-grade structures from groundwater penetration, Penetron Italia worked with the ready-mix concrete supplier to provide an optimal and waterproof concrete mix. About 5,500 m3 (7,200 yds3) of concrete mix was treated with PENETRON ADMIX, a crystalline waterproofing admixture, added during the batching phase of mixing.
As a crystalline waterproofing admixture, PENETRON ADMIX releases a catalytic reaction when exposed to moisture. This reaction generates a non-soluble crystalline formation throughout the pores and capillary tracts normally found in concrete. This formation permanently seals microcracks, pores, and capillaries against the penetration of water or liquids from any direction, substantially reducing the permeability of usually porous concrete.
“As an integral waterproofing solution, PENETRON ADMIX provides low permeability, low shrinkage and crack self-healing properties,” concludes Enricomaria Gastaldo Brac. “This is a highly effective combination for exposed concrete structures in virtually any environment.”
Penetron protects Milan towers: Due to a 66-feet excavation depth for below-grade parking and cellar floors, PENETRON ADMIX was used to protect the concrete structures from groundwater pressure.
