In contrast to modern block types the historic urban block is characterised by a deep hierarchical structure from perimeter (public) to interior towards degrees of privacy.
We use the term ‘depth of block’ to refer to the structure of density of the block and second in a metaphorical sense to suggest the richness and diversity of life sustained by the block. The term metabolism has been applied to describe the interrelatedness – both temporal and topographical of the more or less autonomous activities which the block supports.
An example of this was traced in the Via Milano, Como, blocks where there is an ‘official’ culture on the streets – commercial, offices, clinics, (higher rent activities or public / civic which require a visible presence) : behind which is an ‘unofficial’ culture inside the block of the most extraordinary changing diversity. One cannot make a town of either the or unofficial on their own but rather one needs the whole metabolism – the ‘unofficial’ culture is crucial to the depth and richness of the town.
The blocks that were studied reveal a spectrum from a very dense order (generally closer to the historic centre of the city) with courtyards occasionally the size of rooms to more amorphous blocks consisting of an agglomeration of medium sized edifices. In between are structures where a range of public and semi public spaces are hidden within and penetrate through the block interior.
In general terms the fabric and activities on the perimeter have remained more stable over time. Notably (in the most part nineteenth century) frontages onto the main artery (Via Milano) are consistent. However behind these more linear facades lies a more varied configuration of buildings and uses which evidently change more rapidly – these include more specialised shops, workshops (car repair, fabrication), a bus depot, private houses, schools, institutions with gardens, modern residential buildings with garden courts, professionals offices and small industries plus many more.
Corresponding differences were recognised in terms of the daily cycle of activities as one penetrates the layers of the block. The perimeter remains active throughout the 24 hour cycle, the activity of the interior is more dependent upon opening and closing times with pockets of almost permanent tranquillity (shared residential gardens). Various segments - the area around the school - for example may be extremely animated for short periods and then subside.
The degree to which the hierarchical structure has been retained over time is striking. There is a consistent differentiation between front and back, exterior and interior. The degree to which penetrable layers occur allows for a vast range of conditions and activities. At the same time the hierarchy of secondary streets, arcades, alleys, courtyards and gardens maintains the dialogue across the whole depth. At no point is public life entirely excluded.