Building block Οικοδομικό τετράγωνο (Ο.Τ.) is every single buildable land area, which is included between a validated street plan or between the borders of a settlement and is surrounded by common spaces. (NOK, General Building Regulation)
The First General building code designated the building block as the minimum unit of urban planning and city formation, though, in practice, it was the land plot that played that role. T
The division of space, based on the existing traffic arteries and properties of the under-integration settlements, favored the creation of a large number of small perimeter urban blocks and a dense network of narrow streets achieving in that way more street facades. he building block as a unit was never an object of planning, of architectural practice or social life. Its multifragmentation, divided between lots of small private properties makes it vey difficult to intervene at this scale in an integrated way.
The urban fabric presents a variety of diversifications in its physical structure, partly due to the presence of the geomorphological terrain and mostly due to the fragmented and informal expansion of the city. However the urban blocks and the street network produced, have a common typology. Its main features are their small size, their front development, their piecemeal production, their diversity and their multifunctionality as also its density and insufficient width respectively.
The typologies of building blocks (continuous, free plan, mixed) were first introduced in the 1929 building code. Two boundaries are important to define its shape–the line between the pavement and the land plot (the front plot line) and the building line, which defines the setback of the building mass. The variation of the width between them and the line of the street has given shape to some streets very narrow pavements, to other, little more privileged, the characteristic row front open spaces (there where a setback is obligatory), whereas in the more commercial streets it gave the sideways archades.