Well into the last two weeks of my sojourn in Rome, I was allowed access to the archive of the Istituto Case Popolari, the main builder and provider of social housing in Italy since the beginning of the twentieth century.

The archive is now administered by ATER (Azienda Territoriale per l'Edilizia Residenziale del Comune di Roma), ICP's successor organisation that still holds the fort in relation to Rome's social housing provision and maintenance. It is not open to the public but, after quite a bit of effort, I found out that the door was not fully locked.

The historical collection contains plans and designs chronicling the activity of the ICP across the capital, as well as documents in relation to its architectural and social activities. It is housed in more than seven different locations across the city, making the process of finding and accessing information a very demanding task in itself.

I found myself knocking on the proverbial door of ATER via my unexpected affair with Innocenzo Sabbatini. Sabbatini was a central figure during the 'golden years' of the ICP, his uniquely eclectic creative work spanning the 1920s until his departure from the ICP in 1931. Sabbatini signed quite a few designs; but he also formed part of the collective subject that was the Technical Office of the ICP, headed by his relative Innocenzo Costantini. Especially between 1925 and 1930, the Technical Office produced an unusually large number of highly original designs, with a clear trajectory towards more refinement, bolder experimentation, fruitful dialogue with modern forms and materials, progressive 'stripping down' of traditional forms that produced ever-surprising new hybrids – sometimes across the different facades of the very same building.

The ICP of course continued its activities in the 1930s. Still, there is a clear sense of rupture at some point in the early years of the decade. I am not suggesting that this has something to do with Sabbatini's bizarre departure, when the Technical Office was on the top of its design and management game – because I do not know. The move, however, to more 'economic' and'rapid' housing from 1932 onwards, combined with the displacement of social housing in the distant periphery of the capital, was obvious. Changes in the design and production ethos of the ICP in the 1930s probably have a lot to do with the very different political and social context in which it operated at the time. The growing pace of demolitions in the historic centre and Mussolini's obsession with the destruction of the visible shanty towns (baracche) put undue pressure on the resources of the ICP – a pressure that did not exist to anywhere near the same degree in the previous decade.

Sabbatini left the ICP with a real bang. He submitted his resignation in early 1929 but stayed until 1931, with the agreement of the Institute, in order to complete the projects he had already heading. His last plan, a new social housing complex in the Trionfale district of Rome, was his fitting swansong: a design of bewildering but fascinating complexity, borrowing liberally from his previous work in the same quarter but also in Garbatella, to produce a new kind of mega-complex, with a decidedly stripped-down design sensibility but still ample evidence of his flair and attention to historical contextual detail. The design ended up in the drawer of paper architecture, like so many of the most interesting projects of the Fascist period.

With the invaluable help of the ATER archivist Piergiacomo Alimonti, and the kind permission of the Direzione Generale ATER, I was able to locate the designs for the project. I also came across a wealth of information about other social housing projects and the decision-making context in which they were conceived, produced, and realised (or not). Time has run out of course. But everything about this story – from the accidental question about the 'Casa Economica' in Trionfale by Adam Furman (Rome Prize winner for 2014-15 at the British School of Rome), the urban safaris trying to locate it, the moment of the accidental discovery (albeit covered by scaffolding, now thankfully removed), the communication with ATER, the kind response of Dr Nicoletta Stasio from the Direzione Generale, the hours of searching through the resources of the Ufficio Patrimonio etc etc – shouts serendipity.

So, this could be the beginning. Rome, a city on which I have spent years of my research life, holds up quite a few more surprises. As I pack my bags from the British School at Rome, I feel that I have one more excuse to come back, again and again and again.