Lighting Analysis of Single Pendentive Dome Mosque Design in Sarajevo and Istanbul during Summer Solstice Downloaded from http://meridian.allenpress.com/awg/article-pdf/15/2/163/1448500/arwg_15_2_m0g8207v8222723x.pdf by guest on 30 September 2021 Ahmad Sanusi Hassan and Yasser Arab School of Housing, Building and Planning, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia This study analyzes lighting performance in single-pendentive-domed mosques, a type of architectural design common during the Ottoman era through a discussion ofthe Orhan Gazi Mosque in Istanbul, Turkey, and the Ferhadija Mosque in Sarajevo, Bosnia-Herzegovina. Our lighting assessment was conducted during the summer solstice. This study applies simulation analysis to the selected mosques using Autodesk 3ds Max Design 2012, which creates a lighting simulation showing indoor illuminance levels at hourly intervals. A weather file is added during the simulation process to accurately replicate local weather conditions. Our analysis shows that both mosques have illuminance levels of Scale 3 and 4, brightness levels not demanding high visibility and suitable for reading areas respectively; illumi - nance levels are slightly higher at Ferhadija Mosque than at the Orhan Gazi Mosque. The study concludes that mosques with single-pendentive-domed roofs have interior illuminance levels designed for tasks not demanding high visibility and suitable for reading areas, expressing the lighting quality of sacredness inside the mosque, and that this explains their popularity not just in Istanbul, capital city of the Ottoman Empire but also in Bosnia-Herzegovina. Keywords: single pendentive dome, Ottoman mosques, illuminance level, Sarajevo, Istanbul Cette étude analyse l’efficacité de l’éclairement des mosquées à dôme à pendentif simple, un type architectural commun durant la période ottomane, en prenant les cas de la mosquée Orhan Gazi à Istanbul en Turquie, et de la mosquée Ferhadija à Sarajevo, en Bosnie-Herzégovine. Mesurée lors du solstice d’été, notre évaluation de l’éclairement dans ces deux mosquées a été effectuée grâce à Autodesk 3ds Max Design 2012, qui crée des simulations de niveaux lumineux intérieurs pour chaque heure de la journée. Un fichier météorologique a été combiné à ces simulations pour reproduire l’ensemble des conditions météorologiques locales. Notre analyse montre que les deux mosquées atteignent les niveaux 3 et 4 d’éclairement. Ils sont un peu plus élevés dans la mosquée Ferhadija par rapport à celle d’Orhan Gazi. L’étude conclut que les mosquées à dôme avec un pendentif simple ont des niveaux d’éclairement de niveaux 3 et 4 (respectivement des niveaux ne nécessitant pas une visibilité élevée ou des niveaux de visibilité suffisante pour les espaces réservés à la lecture), ce qui explique leur popularité non seulement à Istanbul, la capitale de l’Empire ottoman, mais aussi en Bosnie-Herzégovine. The Arab World Geographer / Le Géographe du monde arabe Vol 15, no 2 (2012) 163 -179 © 2012 AWG Publishing, Toronto Canada 164 Ahmad Sanusi Hassan and Yasser Arab Mots-clés : dôme à pendentif simple, mosquées ottomanes, niveaux d’éclairement lumineux, Sarajevo, Istanbul Introduction Downloaded from http://meridian.allenpress.com/awg/article-pdf/15/2/163/1448500/arwg_15_2_m0g8207v8222723x.pdf by guest on 30 September 2021 Our objective in this study is to show that the pendentive dome mosque design provides good indoor lighting, thus explaining why this architec - tural style was popular in the design of mosques in the Ottoman Empire. Pendentive-domed mosques are common in contemporary mosque design in Turkey and the Balkan region. This type of construction was introduced into the Balkan region, especially in Sarajevo, in the 15th century by Ottoman master builders, as an architectural marker of Ottoman heritage. Assessment of illuminance levels in these mosques will reveal the relative illumination inside each mosque. Our computer-simu - lated analysis is limited to the period of the summer solstice, when the sun is travelling along the Tropic of Cancer, to assess peak levels of illumi - nance. The summer solstice was chosen on the grounds that how much outdoor light a building design captures is most important when there is maximum outdoor light to be captured, as well as to considerations of controlling the lighting level to express sacredness in the indoor area of the prayer hall. The assessment measures lighting design, lighting quality, and its effects on people inside the existing mosque area, not the design of the space or artificial interior lighting. The Orhan Gazi Mosque in Istanbul, Turkey, and the Ferhadija Mosque in Sarajevo, Bosnia- Herzegovina, are compared via a lighting simulation run on Autodesk 3ds Max Design 2012. A unique feature of a pendentive dome is that it creates a vast interior space, twice as high as a traditional dome, and allows natural light to penetrate inside the mosque, a crucial factor in providing light for the worshippers who gather there. This type of design also maximizes interior reflected light, and thus the architectural features of the building are high - lighted. The light that filters down from the many small windows tucked beneath the dome structure brings light into the space in a way that seems to intensify the mosque’s sense of sacredness (Hillenbrand 1994). Mosques designed with pendentive domes were the work of Ottoman master builders who reinvented the architectural style of the Hagia Sophia, built by Byzantine master builders, with more efficiently designed wall openings (upper and lower windows) to incorporate natural light into the mosque design (Necipoglu 2005). Pendentive dome design is also common in Byzantine architecture. A pendentive dome is essentially a “dome built above a dome,” with an upper dome that seems to be “hang - ing in the air” (Mango 1976, 107–14). During both the Byzantine and the Ottoman periods, architects were restricted to design schemes that could The Arab World Geographer / Le Géographe du monde arabe Vol 15, no 2 (2012) Lighting Analysis of Single Pendentive Dome Mosque Design 165 be accommodated in a load-bearing structure. Because a pendentive dome has no ribs, columns, or ring beams built on the dome and wall structural system, it must be capable of bearing its own weight by means of four giant arches. The upper dome in a pendentive system is supported by four grand arches that, in turn, create the frame for a lower dome. This Downloaded from http://meridian.allenpress.com/awg/article-pdf/15/2/163/1448500/arwg_15_2_m0g8207v8222723x.pdf by guest on 30 September 2021 type of construction has the added benefit of reducing demand for build - ing materials such as stone, brick, and marble; this minimalist approach later led to the development of the concept of dematerialized construc - tion. There are six types of pendentive domed mosques in Ottoman archi - tecture: the single, earring, multiple, duplication, courtyard, and earring courtyard plans (Hassan and Mazloomi 2010a). This study focuses on the single-pendentive-dome design, the most basic of these plans and the most common type of mosque built in the Balkan region, especially in Bosnia-Herzegovina. The building plan of a single-pendentive-dome mosque (see Figures 2 and 4 below) consists primarily of a square and a dome. The square (or rectangular) form on which the dome rests, often punctuated by door and window openings, marks the confined space of the main prayer hall. This square structure, however, cannot immediately accommodate a circular dome above it; tertiary semi-circular elements, known as squinches, are therefore added to bridge the space between the square below and the dome above. The squinches, nestled against the dome, look like triangle domes. In addition to relieving the weight of the dome above, they allow the architect to include a line of small windows along the base of the larger dome, which allow a great deal of natural light into the interior of the building. The dome is indicated on the plan by a circular dotted line, which represents the interior void of the prayer hall, a space twice as high as its ground-floor width or length, under a pendentive dome as the roof cover. The dotted triangles indicate the squinched arches. In some cases, a dotted semi-circle attached to the circular line represents the attached half-dome or semi-dome roof covers. The number of half-dome roof covers may be more than one, depending on the number of half-domes attached to the primary pendentive dome’s structure. Many mosques have an additional riwaq (entrance corridor) area. In a single-pendentive-domed mosque, the size of the dome deter - mines the size of the overall structure the larger the dome, the larger the of mosque (Hassan and Mazloomi 2010b). The dome’s load is supported by four giant arches, which form the ground dome that, in most cases, is hidden in the thick perimeter wall. The joints between these arches and the dome are typically surmounted by squinches. In some cases, up to four semi-domes radiate out from the large dome, providing additional indoor space. The Arab World Geographer / Le Géographe du monde arabe Vol 15, no 2 (2012) 166 Ahmad Sanusi Hassan and Yasser Arab Materials and Methods The indoor lighting performance of the two mosques selected for this study was evaluated using illuminance levels on a measurable scale. Illuminance levels were measured in lux or lumen per metre square Downloaded from http://meridian.allenpress.com/awg/article-pdf/15/2/163/1448500/arwg_15_2_m0g8207v8222723x.pdf by guest on 30 September 2021 (lumen/m 2), essentially the measure of the amount of luminance (lumen) per 1 m × 1 m surface area. Using this measurement, we will determine the indoor lighting performance by comparative analysis (Runsheng, Meir, and Etzion 2009). Building designs that use daylight are considered as having excellent passive design. Daylight, a passive form of lighting, is preferred because it comfortably matches human visual response.