Interpretation of sustainable desert architecture in Ghadames city, Libya

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1. INTRODUCTION
1.1 Background
Desert architecture is a vocabulary that governed the
design concept of the traditional houses while
highlighting their distinctive characteristic solutions,
which can be traced in many of the existing buildings.
It provides a richness of design principles that
“...represented the result of many years or even
centuries of optimisation in relation to the resources
of materials and labour, the activities carried out
within and around the dwelling, the social
organisation of the household, and the climate”
(Evans, 1980). In hot dry climate zones of Libya, the
environmental stresses and climatic hazards in
Ghadames City had influenced the architectural
design of vernacular building that gradually improved
along time in response to the needs of the occupants
and the local climate as well as became well-fitted
with the surroundings. This setting gives real lessons
and significant ideas on how the applications of
sustainable design can maintain indoor comfort and
how the buildings can be more responsive to the
climatic conditions. Moreover, it became a permanent
phenomenon that has historical roots accommodating
several factors approved through public experience.
1.2 Climate in Ghadames
According to the world map of Köppen−Geiger
climate classification (2006), Ghadames city is
classified as a hot arid climate (BWh) in desert
climate, which is also characterized by very hot, dry
air temperatures and dry ground conditions. In winter,
the maximum average temperature reaches about
20°C during day time and the minimum average
temperature is about 3.3°C during night time. The
relative humidity average is between 55~19%;
increasing in night time and decreasing in day time.
However, in summer where direct solar radiation is
very intense, and there is no barrier to outgoing
radiation from exposed surfaces to the sky, the
maximum average temperature could reach about
47°C during day time and the minimum average
temperature could be about 26°C during night time.
The relative humidity average could increase slightly
to 15% in night time and decrease to 11% in day time.
1.3 Ghadames Location
Ghadames City is an agglomeration of Saharan oasis
sited in Libya near the borders of two Arab countries
(Fig. 1). The City is about 340 meters above sea level
and the site coordinates are 30°08' latitude North and
9°30' longitude East.
Figure 1. Map of Libya showing Ghadames location and
neighbours (Geology.com, 2017).
Interpretation of Sustainable Desert Architecture in Ghadames City, Libya
A. Eltrapolsi
Department of Architecture and Urban Planning, Faculty of Engineering, University of Benghazi, Libya
H. Altan
Department of Architectural Engineering, College of Engineering, University of Sharjah, UAE
ABSTRACT: Ghadames is classified as one of the World’s heritage city, combining old town (vernacular) and
new (modern) city. In Ghadames, the design of houses in old town utilised the favourable elements and at the
same time minimised the unfavourable elements of the local climatic conditions by sustainable design of houses
more responsive to the climate in the region. This paper qualitatively highlighted the perfect picture of
vernacular architecture, presenting the strategies of the potential of building design to rethink new architecture
in the light of understanding the dynamics and the strength of vernacular techniques.

It is located about 17 km from Tunisia and 14 km
from Algeria. Famously, the old town is described as
the “Pearl of the Desert” bordered by an oasis that is
protected from the drifting sand and from the high air
temperature of the surrounding desert by palm trees
(Fig. 2).
Figure 2. Top panorama of the old City showing the integration
of buildings with greens (Google Earth, 2017).
2. ANALYSIS AND RESULTS
2.1 Architecture in Ghadames
Old Ghadames City is an “Iconic City” with a scarcity
of natural resources in arid desert. That built by
people who were not schooled in any kind of formal
architectural design. It is self-conscious to the human
eye in buildings’ shape, choice of materials,
arrangements and the concept of passive techniques.
It also demonstrates the principle of climate oriented
architecture, which was a pragmatic remedy to the
effects of harsh climate in arid region. It is divided
into two parts: (a) the old city with traditional
architecture and (b) the modern city with
contemporary architecture (Fig. 3).
(a) Old town (city) surrounded by oasis
(b) New town (city)
Figure 3. Arial photo for Ghadames town (Google Earth, 2017).
According to a field study by Ghadames Municipality
(1980), the glimpses of urban scenes in Ghadames
appeared to represent impressions of segregation,
whereas the society itself claims to have unity,
integrity and organization that can be patterned by a
gradual shift from an urban texture to a building unit.
Figure 4 shows the interpretation of the traditional
city form that is mainly based on principles of
sustainable design approach in old Ghadames town.
Figure 4. The main principles of sustainable design approach in old Ghadames town.

2.2 Sustainable Architecture Attributes in Ghadames
1. “Distinctive Design”, a compact form of the urban
texture, which “... refer to a city that is concentrated
and firmly unified with a consolidation of land uses
in a close and tight physical relationship with each
other and the structures within themselves” (Golany,
1996). The urban pattern of the old City is made of
irregular blocks divided according to the tribes'
distribution and each district has a centrally located
communal meeting place and one major mosque, in
addition to the local mosques (Fig. 5) (Alund, 1987).
Figure 5. Old Ghadames land use plan (El-Agouri, 2004)
The residential units in particular are arranged in a
smaller space with un-equivalent size that provides
enough suitable land, which has been saved adjacent
to the cities for agriculture. In addition, the
compactness character of desert architecture is
described as “Defensive Architecture”, hence, the
defensive wall system is formed by the blind rear
walls of the houses in the perimeter of the village and
the urban design becomes as a big compact fortress
with concentric (De Filippi, 2006). Cumulatively, this
development has been gained through ages, which
distinguishes Ghadames itself in its architecture style
that has been built in a friendship relation with the
nature. Moreover, incredible aesthetics of the City
skyline scale has been dominated by mud brick
constructions that made a strong relationship between
the surrounding landscape and the urban setting.
Thus, the traditional buildings have been designed in
such a fashion as being constructed entirely of local
materials producing an attractive and harmonious
architecture within the environment (Aalund, 1987).
Characteristically, the Ghadamesian houses are
shaped according to the internal desires responding to
the enclosed activities. The houses’ designs have
many shapes as the geometry of buildings is different
according to land division of the City planning.
Therefore, this architectural composition represents a
form that allows only a few visible facades rising in
an almost fortifying manner to a height of about 10
metres and are composed of a number of areas
extending on three floors, from the ground floor,
through the central hall to the roof floor (Fig. 6).
Figure 6. Tall buildings with less openings protecting the city
against the dusty desert winds and providing a defence strategy.
2. “Environment”, harmony with nature through
understanding the site character and climate
considerations. Importantly, the climate is a key
factor determining its design parameters, such as
distance between buildings, building form,
orientation, and building envelope (walls, roof and
fenestration). Moreover, the compactness of urban
texture in hot dry region “...contributes to the thermal
protection because the narrow winding streets are
partially covered; the urban structure is usually a
continuous pattern” (Scudo, 1988), therefore, the
condensed and compressed urban texture allows the
arteries of movement open in the direction of
desirable winds and closed in the direction of
undesirable winds and sand storms (A'zami et al.
2005), (Fig. 7).

Figure 7. Concentration of urban form decreasing penetration
the dusty wind while influencing hot sun radiation on the
passageways.
It gives a good choice for residents to change the
living space for special hours of the day and night of
cold or hot seasons in harmony with the region
(Manioglu and Yılmaz 2008). The buildings in hot
arid climate are shaped so as to allow natural
ventilation in summer “breezes and induce air
movements” through light-well system in the
coverage streets. The construction method has often
used as a high mass skin to counter the varying
diurnal temperatures, which occur from day to night
(Kamel and Ibrahim, 2004). Environmentally, the
irregular shape of urban structure designed to
integrate with the harsh climate and to provide
protection against undesirable winds from the south
orientation sun radiation. Hence, the structures are
made of predominantly local materials, such as the
mud that can maintain fairly steady inside
temperatures of desert regions in spite of the very
high air temperatures and solar radiation. The
physical measurements by authors between 21st-26th
of June 2014 showed how the high thermal capacity
of thick adobe walls and mud roofs can provide
pleasant conditions of 24-30ºC with midday external
air temperatures of 40ºC.
3. “Construction”, using traditional local technique
with local natural materials that shaped the identity of
Ghadames architecture. Construction system is
constituted of load bearing walls built from mixed
organic elements, such as mud brick that constructed
on a foundation of stones where the thickness is
diminishing from bottom to top from 0.75 - 0.60 -
0.50m for structural durability, and also the structure
of ceilings and roofs constructed by bisected and
smoothed trunks of palm tree as first cover. The
second cover, mainly made of ribs of palm leaves are
left in water for three months before plating the mat,
providing support for the floor slab. Later on, the last
cover consists 10 to 15 cm spongy lime stone and clay
with a gypsum mortar. Lastly, about 3cm gypsum
plaster used to cover the walls surface and applied to
lime paint in thin layer as a final coating (Al-Zubaidi,
2002; Mohamed et al. 2006).
4. “Life Context”, the social indoor life, culture
dimension, religion effects and defence strategy is
mainly important in eastern families, especially in
harsh climate, where the control is led by the tribe.
Historians record that Ghadames was inhabited
(4,000) years ago. The town was shaped as symbol of
“... regional architecture ... represented an idiom that
having a distinct identity and being associated with
an identifiable group, and having this association
used ... architectural elements to represent the
identity of a group occupying a piece of land
"(Lefaivre and Tzonis, 2003). The decisive effect on
the sections and the spatial development of Ghadames
was built by seven nomad families who came from
two tribes: Beni Wazit and Beni Walit. Those families
took the land to create numerous habitable buildings
in the form of continuous villages (EL-Agouri, 2004).
2.3 Lessons from Vernacular Architecture of
Ghadames
In principle, vernacular architecture is based on
knowledge of traditional practices and techniques,
and reveals a high regard for craftsmanship and
quality (Sundarraja et al. 2009) as well as represented
as a composition of climatic adaptation that shows the
strength of various settings (religion, culture, building
techniques, etc.) where the natural harmony blends
between architecture and people. However, this is a
meaningful example to contemporary design of
homes and much has to be learnt from their great
history and development of city planning, building
form and construction methods of the past.
According to previous review, indeed, there are many
points can be derived from vernacular architecture,
especially where extreme climates have stretched
human ingenuity and may help to find appropriate
concepts, if not models, to address problems. As a
result, the performance of vernacular architecture has
been providing successful bioclimatic shelter results
from a conscious design of microclimates both inside
and outside the building, based on climatic responses
as follows:
a. The urban texture provides a shelter from the
harsh climate because the narrow snake streets
provide shades and relatively well-lit areas from
regularly spaced light wells each 15 meters that
let cool air circulation deposited during the day
sweep away partially through the buildings and
main gates (Fig. 8).

Figure 8. The covered streets content sitting corners also
providing shades from harsh climate and are used mainly by men
and children.
b. Structurally, the pedestrian network includes an
almost unique system of covered lanes with
formally arranged squares. It is based on a
sophisticated hierarchical system and gradually
leading from the more public to the more private
areas (Azzouz, 2000). This causes air movement
from high-pressure zones to low pressure ones,
where the hot air is replaced with the cooler and
humid air in the shaded passageways, thus
regulating the internal temperature (Al-Zubaidi,
2002).
c. The first point regarding housing design is that the
orientation of the building is the key to achieving
thermal comfort. Orienting the openings is also
very important, thus the best orientation requires
that the building as a whole should receive
minimum solar radiation in summer (Nayak and
Prajapati, 2006).
d. The housing design in harsh climates has shown
that the design of an effective envelope is vital.
The windows are sized to minimize the
penetration of hot air into the housing during the
hot hours of the summer and of cold air during the
winter, while allowing massive ventilation on
cool summer nights (Okba, 2005).
e. The thick walls of materials like mud, mud-brick
with high thermal capacity and adequate
resistance will reduce external temperature so that
the temperature variation at the internal surface is
only about 15 to 20% of the external air. (Evans,
1980).
f. Manipulating the geometry of the housing
envelope is the most fundamental way where the
ratio of the surface area to the volume of the
building (S/V ratio) determines the magnitude of
the heat transfer in the building (Nayak &
Prajapati, 2006).
g. A dense pattern “carpet-planning” layout
provides protection from solar radiation, glare and
hot temperature by providing mutual shading
where groups of buildings are close to each other
(Gut & Ackerknecht, 1993).
Finally, a sustainable context between vernacular
architecture and local climate in terms of design
response to climate is absolutely crucial, particularly
in the context of purely passive environmental
control. However, it is essential to take the wisdom of
the past and evolve a built form, which will be more
humanized, more climate responsive and more
environmental friendly for the buildings of tomorrow
(Radhakrishnan et al. 2011).
3. CONCLUSIONS
Architecturally, Ghadames is an extraordinary place
of aesthetic design with rich and ingenious techniques
which present a series of logical solutions for human
comfort. The orientation and arrangement of
vernacular houses are designed in a way to have
appropriate comfort for residents. These vocabularies
are not only a symbol for architectural identity, but
also successful responses to their social, cultural,
climatic features and effectively providing
environmental design and sustainable key elements in
buildings.
Ultimately, construction materials of the houses that
were traditionally used are mud brick, baked brick,
white lime plastered walls and baked floor tiles.
However, these materials are the important factors in
hot-arid regions, where thermal resistance, high heat
capacity and absorption of the sun radiation through
their external surfaces are the positive characteristics
of local materials (A'zami, 2005; Salama, 2003;
Scudo, 1988).
Nevertheless, the appreciation of design quality needs
developing links between contemporary architecture
and vernacular architectural heritage by introducing
an identifiable architectural character that would
adequately belong to the local environmental
conditions and to the behavioural patterns of the
population of a locality. Overall, vernacular cities
accumulated layers of experience for enhancing
thermal performance by designing the part as an
essential to the whole, and traditionally developed as
compact settlements in practical response to the
environmental stress. In other words, the compact city
form reacts positively in its thermal performance to
regions of harsh climate.

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