Page 32 - Vertical City
P. 32
32 The vertical city
This net density δn has a direct impact on total gross
density δb.
The total gross density δb takes into account the sur-
faces necessary for the totality of the activities in the
city, including dwellings, and diminishes exponentially
with a growing population and tends towards a limit
with growing net density.
The quality of life, equality of opportunity, profes-
sional and intellectual qualifications, financial resources,
network economy and also risks of pollution, conges-
tion and speculative development increase along with
the total gross density.
The graphic in figure 11 illustrates the relationship
between the total gross density, the net density and the
population 14. It assumes occupancy of the territory by
roads and one-level industrial buildings, such as occur-
red in the 20th century. It is no longer sustainable and we
must determine to develop vertically.
Urban development in China is premonitory in this
respect.
A small traditional city of 30.000 inhabitants
(30.000 h), with a total gross density of 100 inhabitants
per hectare (100h/ha) 15 thus occupies an area of 300 ha,
14 Philippe Samyn, “Densité de population et hauteur des construc-
tions. Application au cas de Bruxelles”, in Revue Belge de Géographie,
96th year, 1972, booklets 2 and 3, p. 135-182 [figures 7 à 11].
15 The total gross density has grown to 1.000 h/ha in Hong Kong! The
total gross density decreases otherwise in function with the size of
the city.
