Adaptive Design of the Urban Voids as Passive Cooling Solution for the Medina of Tunis in Contribution to the Sustainable Urban Form

By:  Kenneth Tse Kam Wing

Heritage-led urban regeneration is a hot topic in recent years. When the heritage
relics to be preserved are more than the monuments, mosques, or important historical
buildings, but include the plebian domestic dwellings that altogether constitute the integrity of
the urban form, the concept of repairing the parts and the whole requires more discussions.
Medina of Tunis, situated in Tunisia, North Africa, is a World Heritage Site inscribed by the
UNESCO in 1979. It is filled with the Muslim culture for centuries, and is characterized by the
homogenous compact urban form that is composed of repetitive inward-looking courtyard
houses. The Medina was under the French sovereignty since 1881 until it gained
independence in 1956. Though the French did not demolish the old medina but built a new
colonial town next to it, the lasting effect is that the wealthier population was attracted by the
modern way of living and left the medina. For the past 50 years, the abandoned dwellings
inside the medina were lived by the low-income rural migrants who pay little attention to the
building maintenance. Overcrowded sub-divisions have also led to hygienic and pollution
problems. The medina is therefore under severe threat of urban decay and social
segregation.
To understand better the problem of urban decay and how it adversely impacts the
environment in terms of air movement in and around the dwellings, the rationales of how and
why the dwellings are planned and constructed have been traced back to the Muslim culture
and the climate responsive traditional design. The implications of abandonment in recent
decades towards the degradation of both the urban fabrics and microclimate are discussed.
This research paper considers the intricate and indivisible relationship between the
urban form and the individual dwellings, and investigates the pros and cons of two
rehabilitation projects that took place in Fez and Tunis. The research sees the potential of
adapting the urban voids for a passive cooling solution in enhancing the microclimate for an
environmental sustainability strategy that could lead to a more resilient and sustainable
urban form, presenting a functional alternative to complete reconstruction. It is envisioned
that a stitch in time saves the imminent abandonment, and the strategy can contribute to the
economic viability, social engagement and cultural enrichment.