The project for the Castello plain sinks its roots into at least thirty years of Florentine history, evolving from a simple office district into a true portion of city.
The first hypotheses for a project date back to 1976 when Florence University announced a competition to come up with some ideas for a project for the office district, which was to characterise the northern part of the area.
In 1978, with the second phase of the PIF (Florentine Inter-municipal Plan), new guidelines indicated the need to include more functions in the area (tertiary, managerial, cultural). In 1985, the adoption of the variant to the PRG (General Masterplan) denominated “north-west variant”, stipulated 3 million cubic metres of building, as well as a park covering 60 hectares. In 1998, after years of debate and negotiating, a new variant to the PRG increased the park’s dimensions to 80 hectares and drastically reduced the cubature to a total of 1,400,000 cubic metres. Subsequently, Fondiaria insurance company, owner of the majority of the land, agreed with the local authorities to employ Richard Rogers to redesign the entire area; in 1998, with Rogers’ plan a new urban model was introduced, which rejected the zoning of the previous master plans, based on multifunction.
In 1999, on the PUE’s approval of the local authorities’ initiative, Rogers’ project was confirmed.
Nevertheless, owing to contrasting political views, the project did not go ahead, and the local authorities, following negotiations in which Fondiaria ceded 24 hectares of land to the Municipality of Florence for the construction of the so-called “Scuola dei Marescialli” a vast military police barracks  drew up and approved a new varient to the PUE (Unitary Building Plan) in 2004. The authorities slightly increased the park’s dimensions from 800,000 sq.m. to 805,000 sq.m, while the total cubature remained as was, including, however, also the public military part. In addition, a clause was added for flexibility (20% of useable surface area could be shifted from one lot to another). Hence in the new configuration, excluding the military areas already under construction, there was a theory that of the 160 remaining hectares, one half was destined for park land and the other half for building. In 2006, for the design of the park, Fondiaria’s new owner called French landscape designer Christophe Girot, who teaches at the ETH school of Zurich, and also Studio Archea, in particular, Florentine-born Marco Casamonti.
The two studios, with the historical and critical advice of Vittorio Savi, embarked upon a complex study and research, establishing the general criteria of the new detailed master plan. The main paths of development involved the need to introduce environmental sustainability and varied architectural projects able to culturally define the intervention as a new part of the city. The main strategic elements are: functional mix (no longer dormitory or exclusively office and residential districts, but an area of shops, residences, offices and integrated public activities); architectural mix (detailed projects carried out by various architects, in line with important urban transformation projects carried out with this methodology throughout Europe); pedestrianisation of the area (through the availability of artificial terrain which contains road networks and car parks); integrated mobility (through the planned link of the area with a new tram line connecting the area of Castello with the centre of Florence); important public functions (with the plan of shifting the offices of the Province and Region to the gates of the city, near the motorway and airport); public use of the terrain (through the articulated people-friendly distribution of surfaces to develop, completely for public use); the park as a structural element (where greenery is not simply considered an accessory element but a distinctive characteristic of this new part of interconnected urban fabric).
From an architectural point of view, the project establishes a hierarchy in relation to the limits of the building: toward the city and street, the façades are solid and rigid; in the park, on the other hand, the buildings open up, favouring co-penetration between the constructed space and green space.
The urban fabric in the project appears in continuity with the consolidated city, constantly evolving among a series of squares which cross a pedestrian main street at regular intervals, surrounded by porticoes and shops, culminating in the square where the Regional and Provincial Offices are to be located.