Twenty-five years of working with existing buildings have taught us that the structures that withstand the test of time do so because someone had the courage to reinterpret them. Adaptive reuse requires a deep understanding of what exists before imagining what could be. Above all, it requires taking a position. Ours is rooted in a conviction: regenerating the public housing stock built after the Second World War is today the country’s most urgent and most underestimated architectural challenge.

These buildings are facing a state of energy, structural and social deterioration that can no longer be postponed. And they are inhabited. Intervening in them is a civic responsibility before being a technical challenge.

This project is part of a path we began a few years ago, when Park took part in the first phase of Energiesprong Milano, working on the ERP complex in Via Sant’Erlembaldo, in the Gorla neighbourhood. In that context, we developed design strategies all based on a common principle: prefabrication as a tool capable of generating forms, variations and relationships. That research prepared us to address a more concrete and ambitious challenge.

With this awareness, we joined the Call for Solutions Next Gen ERP launched by EDERA, the organisation coordinating Energiesprong Milano, funded by Fondazione Cariplo, which works to transform an industrial culture of building regeneration into a widespread practice, integrating it into institutions, public tenders and incentive policies. It is a form of cultural advocacy, in the noblest sense of the term.

The selected site is the complex at Viale Omero 15, in Milan’s Corvetto district. Six identical IACP residential blocks from the 1950s, oriented east-west and owned by the Municipality. An ordinary place, in the most precise and valuable sense of the word: a representative example of a building type that exists in enormous quantities throughout Italy and that is still waiting for a credible model of systematic regeneration.

The structure of the Call involved a direct comparison between two approaches. The first, conventionally defined as BAU (Business As Usual), relies on consolidated technologies: structural reinforcement through a PBO fibre-reinforced system applied to the existing envelope, external insulation, window replacement, and a new metal access walkway structure to ensure accessibility. The second, called ES (Energiesprong), is based on industrialised prefabrication: offsite-produced concrete panels that wrap the entire building, simultaneously performing the functions of thermal insulation, seismic reinforcement and architectural transformation of the façade.

The aim was not to identify a winning solution, but to rigorously document differences in cost, construction time, impact on residents and quality of the outcome, contributing to a data-driven discussion.

The figures emerging from this work speak clearly. The ES system costs 32% less than BAU while achieving the same performance levels, and construction is completed in approximately 43% less time. However, the reduction we consider most significant, and one that is rarely taken into account in comparative analyses within the sector, concerns the disruption experienced by residents during construction. Since panel production takes place in a factory in parallel with the first onsite phases, the period of disturbance to daily life is reduced by 72% compared to a traditional approach. For those living in these apartments, this is perhaps the most tangible outcome of the entire project. Added to this is a factor that architectural debate often overlooks: industrialised prefabrication significantly reduces risks for construction workers, moving operations that would otherwise take place at height on scaffolding into a controlled production environment. The sustainability of a project must also be measured through this lens.

The work developed together with our team of partners, including Massetti Engineering and engineer Enzo Cattarina for the structural design, Camuna Prefabbricati for prefabrication, Innova for building systems, Rockwool for insulation, Delta Dore for home automation, DAW for finishes and Wood Beton as general contractor, finds its clearest identity where technology meets architecture.

The transformation strategy placed inclusivity and accessibility at the forefront, enabling contemporary and shared use of spaces through the introduction of two new lift cores and an external structure connecting all floors. These new walkways, required to connect the lift cores with apartment entrances, become shared outdoor spaces overlooking the neighbourhood. Places for pause, encounters and proximity. A spatial typology deeply rooted in Milan’s architectural culture, which has demonstrated over time its ability to foster social cohesion wherever physical space enables it. Giving these buildings terraces that were previously absent means concretely expanding the quality of living, adding a dimension that residents had never experienced before.

The façade panels, differentiated by colour from one building to another, remove the complex from the anonymous repetition of its current condition. Each block gains a recognisable identity, and each community a visual reference of its own. It is a project that works on perception as a fundamental condition of living, based on a conviction developed through years of research into adaptive reuse: the dignity of space and the quality of life are inseparable values.

From a systems perspective, the choice of the Water Loop Heat Pump system reflects the same logic guiding the entire project: minimal invasiveness, maximum efficiency. The intervention focuses on the two ends of the energy system, the central plant and the apartment terminals, while leaving the existing distribution pipes unchanged. Gas boilers are eliminated, summer cooling, previously completely absent, is introduced, and a rooftop photovoltaic system is added. The result is a 71% reduction in operational energy consumption compared to the existing condition, achieved without emptying apartments, forcing residents to relocate, or requiring months of internal works.

Beyond the specific results, this project provides a methodological confirmation tested within a real and demanding context. Architectural quality and economic sustainability can reinforce each other when the process is correctly structured, when the supply chain is integrated and when prefabrication is guided by a clear vision. Public housing is one of the fields where architecture can generate real and lasting value: for people, for cities and for the quality of the cultural debate surrounding the future of the built environment.

Viz by Park