Vernacular domed houses of Harran, Turkey

Abstract

The beehive domed vernacular houses of Harran, Turkey were studied from the point of view of historical origin. The factors like climate, social and urban structure, spatial organization, construction and materials which effected the form of the buildings were considered. It has been discovered through this study that Harran houses can be built rapidly like tents, with burnt or sun-dried shallow bricks. Vernacular architecture of Harran illustrates the concepts of flexible building, climatic building design and re-usable building materials concepts. Possibilities of using this construction type in our times is discussed.

Full text

HABI¹A¹IN¹¸. Vol. 22, No. 4, pp. 477 —485, 1998
(1998 Elsevier Science Ltd. All rights reserved
Printed in Great Britain
0197—3975/98 $19.00#0.00
PII: S0197-3975(98) 00027-7
Vernacular Domed Houses of
Harran, Turkey
M. B. O®ZDENIZ*, A. BEKLEYENs,I.A.GO®NU®Ls,H.GO®NU®Ls,H.
SARIGU®Ls, T. ILTERs, N. DALKILIhhhs, M. YILDIRIMs
*Karadeniz ¹echnical ºniversity,¹rabzon,¹urkey
sDicle ºniversity,Diyarbakir,¹urkey
ABSTRACT
The beehive domed vernacular houses of Harran, Turkey were studied from the point of
view of historical origin. The factors like climate, social and urban structure, spatial
organization, construction and materials which effected the form of the buildings were
considered. It has been discovered through this study that Harran houses can be built
rapidly like tents, with burnt or sun-dried shallow bricks. Vernacular architecture of Harran
illustrates the concepts of flexible building, climatic building design and re-usable building
materials concepts. Possibilities of using this construction type in our times is discussed.
(1998 Elsevier Science Ltd. All rights reserved
Keywords:vernacular architecture; housing; flexible building; climatic design; sustainable
habitation
INTRODUCTION
Harran is a plain and a town in the southeast of Turkey, between the rivers of
Euphrates and Tigris. It attracts attention with its interesting vernacular architec-
ture. This building form is not used in other parts of Turkey, where the main
building material is adobe. At present, similar building forms are seen only at South
Italy (German, 1974), Cyprus (Go¨kie, 1979) and at Fezzan and Kufra areas of
Libya (Awotona, 1990). It is not known how this unusual building form has
evolved. As architects, the authors wish to find out the factors that generate it. The
historical background of vernacular Harran architecture, its relation with the
similar building forms in other parts of the world, the urban and spatial organiza-
tion of Harran houses and the possibilities of their use in our times are discussed.
The thermal performance of the houses with their interiors cool in summer and
warm in winter is well known by the local users. However, it was discovered
through this study that another feature of Harran house is its rapid construction.
The previous studies on Harran houses were limited to a number of photographs
and plan sketches. This study aims to leave an architectural document to other
researchers and to draw international attention to the conservation of Harran.
Correspondence to: Mesut O® zdeniz, The Eastern Mediterranean University, Department of Architecture,
Gazimagusa, TR Northern Cyprus (Via Mersin 10, Turkey). The remaining authors can be contacted through The
Department of Engineering and Architecture, Dicle University, 21280 Diyarbakir, Turkey.
477

STUDY
It is necessary to take a short look to the history of Harran, to understand the roots
of Harran’s conical domed houses. The known written documents about Harran
indicate that its history goes as far back as 2500 BC. Because of its location on trade
routes and proximity to the fertilized Mesopotamia peninsula, many civilizations
have flourished at Harran. She had very splendid and unfortunate periods through-
out her history. For example, she was a capital city of the Assyrian Empire and of
the last Emevi Caliph Mervan 2.(744—750AD). The Harran University which has
been known since the Early Ages, had its golden age in the 8th century AD, during
the Abbasian rule of Harun Res
,it (Ku¨ rkcu¨og\lu, 1995). Many scholars graduated
from this university. Translations from Greek and Assyrian documents to Arabic
were made. There were studies on philosophy, mathematics, medical sciences and
astrology. The town was plundered by the Mongol King Timur in 1260 AD.
Although the Ottoman King Yavuz Selim repaired the demolished university, its
importance diminished afterwards (Nahya, 1983).
Etymology
The name of ‘‘Harran’’ had been mentioned in ancient Assyrian and Hittite
documents. It means ‘‘intersection of routes and travel’’. For thousands of years this
name has remained with minor changes (O® zfirat, 1994).
Climate
Harran has a hot—dry climate. Its height above sea level is 345 m. There is a wide
diurnal and yearly temperature range. The annual precipitation rate is rarely over
40 cm. The mean maximum temperatures in July and August is 39°C and the mean
minimum temperature in January is 2°C.
Social structure
In the large part of her history, she was the cultural and religious center of settled
societies. In the last 500 years, she was used as the temporary settlement of nomad
societies (Dog\anay, 1994). Today almost all the population of Harran Plain speak
Turkish. In addition, 19% speak Arabic and 10% speak Kurdish as their mother
language.
Tribal life and the patriarchal family structure of the past has been changing
during the last 50 years with the transition to irrigated agriculture. At present,
seasonal nomad and settled habitation has became predominant. The changes in
social structure has been reflected in the architecture.
Roots of the vernacular architecture
The town of Harran with the beehive-shaped houses is located on a tumulus
and surrounded by ancient city walls. History faces the danger of being lost
because although she was declared as the historical site by the Department of
Culture, there isn’t enough scientific excavations and appropriate conservation in
the area.
It is necessary to search the roots of Harran houses through the Mesopotamian
civilizations. At some of the stone reliefs of Assyrians, who ruled the area during
2500—600 BC, figures similar to Harran houses are seen (Nahya, 1983). Me-
sopotamia excavations show that domed building forms with a square front court
or room were used as early as the 7th century BC (Mu¨ ller and Vogel, 1974). These
domes had diameters of between 5 and 10 m (Fig. 1).
478 M. B. Ozdeniz et al.

Fig.1.Domed building forms found at Mesopotamia excavations belonging to 7th century BC.(Mº®¸¸ER and
»OGE¸, 1974).
Wood is rare in the region because of the dry climate. Thus, people built their
houses with the materials they could find easily, like adobe, brick and a little bit of
stone. Another characteristics of the Harran house is that it can be built very
rapidly. The nomadic life style and the climatic conditions had forced people to
adopt a building form which can be built easily like a tent but which resists heat and
cold.
An old craftsman interviewed confirmed some of our observations. ‘‘We have
learned how to build these conical domes from the domes of ancient buildings
during excavations. The present houses were built around 1939 when I was a boy.
We needed 1300 bricks for a single dome. We provided these bricks from the ruins
of ancient buildings. We have never produced bricks at Harran. I could build two
domes in a day’’, he told us. German (1974), who studied the similar building forms,
‘‘the trullo’’ of South Italy, has written that they were evolved at the 15th and 16th
century AD. He points out that taxes were paid on the basis of houses at that time.
People adopted a building form which could be easily dismantled before the visit of
the tax collector so that they did not pay taxes to the feudal lord. They erected their
houses quickly afterwards. We can say that the form of Harran houses were
adopted because they could be built with locally available materials and quickly by
the nomad people (Fig. 2).
Since the main building materials are mud, adobe and clay brick, the life of the
buildings is limited. It can be said that the present buildings are not more than
70—150 yr old. It is strongly possible that the conical domed Harran houses were
ruined, forgotten and rebuilt many times during the flow of history. There had been
also changes in their form over time. The 12th century AD traveler Ibni Cubeyr
mentions the domed buildings of Harran (Ku¨ rkcu¨og\lu, 1995). The 17th century AD
traveler Evliya Celebi writes that Harran has been abandoned and the houses were
made of adobe (Zilliog\lu, 1966). He also writes that the tomb of scholar Seyh Yahya
on the northwest side of town is covered with a big dome although he does not say
anything about the domes of the houses. Probably the conical domed houses were
not present at that time. A 19th century photograph of Harran shows that conical
domes were erected on the ground like tents, while in the 20th century all the
conical domes were built on square planned cubical bases (Fig. 3). After the
second-half of the 20th century, earth roofed, rectangular planned rooms were
added to them. Earth roofs are either flat or inclined on four sides.
ºrban structure and spatial organization
The street layout of Harran is organic like the forms of the houses. People
belonging to the same tribe wish to live together. Thus Harran houses are adjacent
Vernacular Domed Houses of Harran, Turkey 479

Fig.2.¹rullo’s of South Italy belonging to 15th and 16th century AD.(Drawings only,from Mº¸¸ER and »OGE¸,
1974).
Fig.3.A19th century photograph of Harran (¼ith the courtesy of Dr.Cahit KºRKCºOG¸º).
or very close to each other. As a result of this, the street layout is casual and natural.
People in transition from permanent to temporary nomadic life who make their
living by agriculture and stock-breeding had to live close to the production
activities. Thus, at their shelters, they made spaces not just for themselves but also
for their animals and products.
At present, houses with conical domes covering square rooms are in majority.
Each room covered with a single dome is a building unit and serves as living room,
kitchen, store or barn. These rooms are connected to each other with internal doors
or arches. Some of the rooms are opened to the courtyard with a small door.
A bathing place is included in the room which serves as a kitchen. In winter, the
kitchen is also used as a living room and is locally called a ‘‘tandirlik’’. The toilets
are not placed within the building because water is scarce. They are placed at
a corner of the courtyard away from the rooms. In some courtyards there is also
a well close to the center.
The income level of the building owners, family population and their necessities
determine the number of rooms. As the family enlarges new rooms are added to the
480 M. B. Ozdeniz et al.

house. Thus, Harran vernacular houses are typical examples of flexible or the
extendible house concept. In the spatial organization of Harran houses, the rooms
are arranged on one side of the courtyard in one, two or three rows. The rows are
positioned on east—west axes, thus the solar radiation from the west is shaded by
the domes and cool spaces are obtained. However, there are houses which do not fit
to this generalization. (Figs. 4 and 5).
Control of physical environment
There are ventilation holes at the sides of each conical dome, and another single top
hole which serves both as chimney and ventilation hole. In the opening of side holes
there isn’t any preferred direction. There are holes opened to four, three or two
directions. However, the holes always face each other to allow cross ventilation. On
the side walls of the cubical base are windows, opening both to the courtyard and to
the street. Window sizes are as small as 30]40 cm. Holes and the windows are
closed in winter and opened in summer for natural ventilation.
Fig.4.Plans and sections of a typical Harran neighbourhood.
Vernacular Domed Houses of Harran, Turkey 481

Fig.5.Plan of Cuma Alma House near the Harran castle.
In summer, the hot air within the building ascends and is discharged from the top
hole. The smoke test carried out on a summer day indicated that the air entering
from the doors, windows and holes ascend in rotating order. The rate of airflow was
at 2.5—5.0 m/s at various points within the house. Thus, a continuous natural
ventilation is provided. As a result of this, very cool spaces are obtained under the
extremely hot exterior temperatures of summer. It was not possible at the time of
this study to carry a systematic thermal analysis of the buildings. However, an
initial measurement of outside air temperature in the shade and internal air
temperature, on a hot June day at 14.00 hr, showed 8°C temperature difference (28
and 20°C, respectively). The buildings have relatively lower external surface to
volume ratios because of their domed and cubical forms. Thus, with the closed
holes and windows the building looses little heat in winter. Besides, adobe walls
60—70 cm thick provide a good thermal insulation and time lag.
Construction and material
The conical dome is built by sliding the flat bricks inward at each row. They are
either sun dried or burned bricks collected from older ruins. The thickness of the
dome wall is about 25—35 cm. This is in a sense a fake dome, because unlike in
ordinary domes, the loads are conveyed in a vertical direction (Figs. 6—9).
Fig.6.A general view of Harran.
482 M. B. Ozdeniz et al.

Fig.7.A house at Harran.
Fig.8.A half ruined dome displaying the structure.
Fig.9.An inside view of a Harran dome.
The tops of the domes are left open as chimneys. The domes are not same in
diameter and height. They are 3—5 m high from the base and rendered externally
with mud every year in June. For this purpose stone projections are left on the sides
of the domes to be used as scaffolding during rendering. Internal rendering is done
as high as a man’s height.
Vernacular Domed Houses of Harran, Turkey 483

At the square planned base walls, sun-dried adobe, brick and a small amount of
stone are used. Since all the bricks are hand made their sizes show variance.
However, on average a complete brick size is 24]24]4.5 cm and a half brick size is
13]24]4.5 cm. Generally, stone is used between the top corners of the base walls
and the dome. A limited amount of stone is used at Harran houses. Some of the
bricks have been obtained from the ruins of ancient buildings. This kind of building
materials are locally called ‘‘devsirme’’ meaning ‘‘the collected’’. Even stone carv-
ings of the ancient civilizations can be seen on some Harran houses.
Only mud mortar is used in joining stones and bricks. Sand and lime is never
used. Sliced straw is mixed only to the mud rendering. Straw is not mixed to the
clay of sun-dried adobe.
CONCLUSIONS
Harran houses which were used as dwellings in the past, are now being used mostly
as barns and store houses. Most of these houses are in desolate positions. The local
inhabitants are very friendly, but not prosperous and cultured enough to restore,
conserve or provide the hygienic services of the houses. Since the seasonally nomad
society is in transition to a settled society with the construction of Southeast
Anatolia dams, there is a need for new housing. The new houses are being built
outside the ancient city walls. They have no architectural relation with the vernacu-
lar architecture of Harran.
It is necessary to prepare a conservation program for the town of Harran. This
program should not be in the form of repair or demolition prohibitions to the
existing buildings, as it is applied at present, but it should be to encourage
restoration. There is only one building which has been restored by the Department
of Culture and it is being used as a museum. The number of examples restored by
experts should be increased in order to persuade local residents to conserve their
houses. Expert and official aid is necessary for the conservation of Harran.
The building components used at vernacular houses of Harran, like sun-dried
adobe bricks, are not long-lasting materials. The standard brick size and shape
being produced in Turkey at present, does not allow for the construction of conical
domes. It is necessary to establish a small-scale brick factory to produce shallow
bricks. This will help in saving the historical sites, repairing the old buildings, and
building new conical domed houses.
The origin of Harran houses goes back to the ancient Mesopotamian civiliza-
tions. It has shown changes over time. It has been forgotten and rediscovered
through excavations. Sometimes the conical domes were built just on the ground
like tents. Sometimes as it is in our days they were built on square planned bases to
obtain roomy spaces. The addition of these square planned spaces below the domes
has increased the buildings’ strength against the lateral forces. At the site of the 19th
Century photograph, showing the tent-like domes, not a single dome remains
today. Their bricks were either collected or they were demolished through earth-
quakes because of their weak structure. It is necessary to study the buildings’
structural performance to verify this observation.
Vernacular Harran houses bear the concepts of ‘‘flexible building’’, ‘‘reusable
building materials’’, ‘‘environmentally friendly building’’, ‘‘climatic building design’’
and ‘‘sustainable habitation’’ which are popularly being discussed in architecture.
Single-storey house units, which are connected to the adjacent units with arches
or doors, provide a flexible building. They can be extended as new needs arise. For
people whose income is limited, it is beneficial to built houses with two or three
units, and add new units in later years.
Burnt clay bricks joined with weak mud mortar allows their re-use. The domes
are not plastered internally. However, the external rendering is made of mud
484 M. B. Ozdeniz et al.

mortar with straw in it. After the winter rains, the rendering is renewed every year.
It is necessary to find new methods of external rendering, which is not expensive,
has longer service life and has the color of earth. More research is needed to find out
the performance of mud plus cement rendering.
The main building materials like clay, brick and natural stone are produced or
provided locally. They do not possess any environmentally hazardous agents. The
use of these materials with mud rendering produces an environmental-friendly
building.
At a time when modern environmental control devices were not available, people
tried to find indigenous ways of climatic control. The Harran house is a good
example of climatic building design in a hot dry climate, with the thermal insulation
and heat capacity of the building envelope, shading of the buildings by each other
against solar radiation, small size window and door openings, and ventilation holes
for winter. Further research is necessary to analyze thermal performance of Harran
houses.
It is not practical to conserve an old site without inhibiting it. Since the need for
new housing at Harran continues, the present vernacular buildings constructed by
a seasonally nomad society can be used by the settled society of today and
tomorrow, with the additions of hygienic equipment. Thus a sustainable habitation
can be formed.
The authors, whose own residential experience is in crowded towns, felt peace
while studying the inside and outside of the vernacular Harran houses. The random
layout of the houses provided a natural-looking environment.
It was discovered throughout this study that vernacular Harran houses were
built through a rapid construction technique. A single worker can construct two
units of this load bearing structure in a day without any need for much technical aid
or advanced construction machines. Thus, it could also be considered as a way to
overcome housing shortages in the Third World countries.
This vernacular building environment encounters the danger of being lost. It has
many secrets to inspire modern architecture.
Acknowledgment—The authors acknowledge Prof. Dr. Zu¨ lku¨fGu¨ neli, the Dean of the Faculty of Engineering and
Architecture of Dicle University, Diyarbakir. Without his initiation and assistance this study could never have
done.
REFERENCES
Akbulut, I. (1996) Harran. Arkitekt. No 443. December pp. 89—91.
Awotona, A. (1990) Housing in Libya: 1950—1980. Habitat International 14(1), 55—85.
Dog\anay, F. (1994) Sosyal ve Ku¨ ltu¨ rel Do¨nu¨ sme Su¨ recinde Harran Ovasi ve GAP Uygulamasi. Ankara: TC
Basbakanlik Devlet Planlama Teskilati SosyalSekto¨ rler ve Koordinasyon Genel Mu¨du¨ rlu¨gu¨.
German, A. (1974) ¹rullolar.Mimarlik.(5) pp. 34—37.
Go¨kie, G. (1979) Geleneksel Mimaride Stru¨ ktu¨r.½api Dergisi (33) pp. 19 —28.
Ku¨ rkcu¨og\lu, A. C. (1990) Ruha’dan Urfa’ya 1780 —1980. S
,anliurfa: S
,anliurfa Belediyesi Ku¨ ltu¨ r veEg\itim Mu¨du¨r-
lu¨g\u¨ Yayini.
Ku¨ rkcu¨og\lu, A. C. (1995) Tarih ve Tarim S
,ehri Harran. Ankara: Harran Ko¨ ylere Hizmet Go¨tu¨ rme Birligi Ku¨ ltu¨r
Yayinlari.
Mu¨ ller, W., Vogel, G. (1974) Atlas zur Baukunst. Tefeln und Texte, Band 1. Mu¨ nchen: G Auflage dtv. GmbH und
KG.
Nahya, O. (1983) Urfa-Harran Bo¨ lgesinde Geleneksel Halk Mimarisinde Tug\la-Tas
,-KerpiiEvler º®zerine Bir
Inceleme.II.Milletlerarasi ¹u¨rk Folklor Kongresi Bildirileri, Vol. 5, pp. 139 —147. Ankara: Milli Folklor
Aras
,tirma Dairesi Basbakanlik Bas
,imevi.
Naumann, R. (1991) Eski Anadolu Mimarlig\i. Ankara: Atatu¨rkKu¨ ltu¨ r, Dil ve Tarih Yu¨ ksek Kurumu, Tu¨ rk Tarih
Kurumu Yayini.
O® zfirat, A. (1994) Eskimag\da Harran.Istanbul, Arkeoloji ve Sanat Yayinlari.
Zillioglu, M. (1966) Evliya lelebi Seyahatnamesi. Vol. 3. Istanbul: U® idal Nes
,riyat.
Vernacular Domed Houses of Harran, Turkey 485