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ScienceDirect Procedia Environmental Sciences 38 (2017) 220 – 227

International Conference on Sustainable Synergies from Buildings to the Urban Scale, SBE16

The Regeneration of the Commercial Triangle of Athens; Sustainability Rationale E. Alexandria,*, E. Kralia, E. Melabianakia, G. Neofytoua, S. Peristeriotia, K. Agorastoub a Division of Public Spaces, Μunicipality of Athens, Athinas 16, 105 51 Athens, Greece Division of Urban Green and Environment, Μunicipality of Athens, P. Kanellopuolou 5, 115 25 Athens, Greece

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Abstract In this paper the rationale of the bioclimatic regeneration of part of the commercial triangle of Athens is presented. In this 11 ha area, identified by three streets in the form of a triangle, the most vivid commercial activities have been taking place, from the transformation of Athens into a capital city in the 19th century, up to late 20th century, when the upcoming of “malls” displaced consumption habits from small shops to large shopping centres. As it is a place that has been either within the city walls or at the outskirts since antiquity, its geometry is very much affected by ancient and medieval Athenian city planning, which is explored and highlighted in this regeneration project. The commercial triangle area today is characterised by a mixture of neo-classical and modern buildings, as well as simplexes of pedestrian streets. The landscape of the area is being reshaped as the old uses that reflect the former economic backbone of the city, are displaced or replaced by new ones which are more related to the industry of entertainment. In this paper, a brief spatial description and historical review of the area is presented, pinpointing to the political and municipal decisions that have affected the area, highlighting the conflicts that the area faces today. Existing land use is monitored in detail and compared to past ones. The sustainability rationale of the regeneration of the public spaces of this area is presented, taking into consideration environmental issues (pedestrianisation of narrow streets, environmental footprint of used or reused materials, recycling municipal waste, low energy consumption street light, construction site measures), bioclimatic issues (microclimatic considerations, surface materials, placement of vegetation in narrow streets), cultural issues (putting forward the area’s historic footprint through the design) as well as social issues (conflicts that might arise from competitive or incompatible land uses), trying to achieve a holistic sustainable regeneration approach. © 2017 2017Published The Authors. Published by Elsevier B.V. © by Elsevier B.V. This is an open access article under the CC BY-NC-ND license Peer-review under responsibility of the organizing committee of SBE16. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of SBE16. Keywords: pedestrianisation; regeneration; commercial triangle of Athens; bioclimatic design; land uses.

* Corresponding author. Tel.: +30-210-3843418; fax:+30-210-3219706. E-mail address: [email protected]

1878-0296 © 2017 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of SBE16. doi:10.1016/j.proenv.2017.03.180

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1. Introduction When designing bioclimatically for open, public spaces more criteria and parameters are set when compared to a single building design. The possible designs are limitless; nonetheless shadow is a very important factor, especially in southern climates1. Apart from solar and wind exposure, the ecology of structural materials and the life cycle of the project, issues of mobility, prioritising pedestrians and cyclists, waste collection and treatment, the history and character of the area, its existing land uses and trends, issues of safety as well as social justice are put forward, amongst other criteria of sustainable design. The 11 ha area that is designed according to this rationale is part of the Commercial Triangle of Athens, in the historical centre of the Municipality, enclosed by Athinas Street, Evripidou Street, Praxitelous-Lekka Street, and Perikleous-Athinaidos-Agia Irini Street. Today, five year after the economic crisis started in Greece, the lack of preservation of public areas, in relation to the disserted buildings and shops exhibit a landscape of abandonment in the city’s historic centre. In this paper, the research made for undoing these conditions from the Commercial Triangle, with main tool the sustainable design of public spaces is presented.

2. Background Research The methodology that is followed for recording the status of the area today consists of in situ measurements and observations, during different periods of the day (in the morning, in the afternoon –when a lot of commercial shops shut down, and at night) as well as different seasons (autumn/winter –November 2014-Febrouary 2015- and spring/summer –April-June 2015). Maps of the ancient city, historical texts and respective bibliography are collected and examined, so as to understand the urban transformations that have taken place in the area. Climatic data is collected from meteorological stations near the area. Interviews with people who work in the area take place, as well as with people who inhabit or frequent in the area. The collected data are analysed and compared with existing data and studies on the Commercial Triangle. 2.1. Historical Background The Commercial Triangle of Athens is located in the historical city centre of the Municipality of Athens. Since prehistoric times, this area has been inhabited, either within or outside the city walls2. The area has been characterised by randomly placed, narrow streets, as there were no city planning regulations in ancient Athens 2. That is why the ancient streets of the commercial triangle have irregular orientations, small widths, with very little space for vegetation. Apart from that, the area has been characterised by the lack of vegetation since 600 BC2, up to the 1980ies, when the first pedestrian streets in the area were established 3 and trees were planted. In fig. 1 the results of the bibliographic research in the evolution of the area are presented, comparing the formation of the city in the studied area in 500BC (fig. 1a) and in Medieval times (more specifically during 14561687AD) (fig. 1b) in relation to today’s streets. Through this bibliographic research, it has been also found out that ancient Athens was built on small rivers, tributaries and streams2, whose empoldering has affected the geometry of some streets. In the instance of Kalamiotou (cane) Street, the empoldering of small rivers that has taken place from antiquity to medieval times and up to date can be easily observed in fig. 1a and 1b. With the formation of Athens as the capital of Greece in the 19th century, commercial uses as well as crafts / small industries started taking place in the area. Most of the ancient and medieval streets remained the same, while two North-South oriented parallel streets, Athinas and Eolou Streets, were made, facing the Sacred Rock of the Acropolis, creating irregular angles with existing streets4. The area developed rapidly. Eolou Street was a central axis of the new city, with two-floor buildings and land uses such as residencies (at the upper floors), commercial uses (on the ground floors), hotels and leisure facilities5. Eolou was a street used a lot by pedestrians and not by vehicles, while public transport passed through it. The commercial and small industries uses dominated over the rest uses (residences, services). As time passed by, the social character of the area changed, becoming a more working class area, the border between the eastern part of the city (inhabited by the upper class) and the western part (inhabited by the working class)6.

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City wall

City wall Ancient street

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Kalamiotou street

Medieval street

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Kalamiotou street

Fig. 1. (a) Ancient streets and city walls around 500BC, in relation to today’s streets; (b) Medieval streets and city walls (1456-1687 AD), in relation to today’s streets. The selected area of the commercial triangle is mentioned with a red line. The sources of the ancient and medieval streets are7 and2, respectively.

Today, the commercial triangle is formed by the labyrinthine of ancient and medieval roads, as well as the NorthSouth oriented 19th century streets. It is characterised by a mix of 19 th century traditional and neo classical buildings (two to three floors), as well as modern, up to 8 floor buildings. The most dominant land use on the ground floors is commerce. Due to the narrowness of the streets, there is shade in areas with high buildings both during winter and summer. Nonetheless, some streets receive summer sun, especially at noon. Due to the ratio of narrow streets and high buildings, air velocity at street level is very low. Twenty four streets are characterised as pedestrian streets (total area of 26,198m2). Only eleven of them are pedestrian streets today (12,887 m2). Most of these (76% of the total constructed pedestrian streets) were made during the 1980ies. 13% was made in the 2000ies and a smaller part (11%) in 2012. Regarding mobility, the commercial triangle, located in the city centre, is close to three subway stops; Monastiraki, Syntagma and Omonia, while there are bus lines that surround it. Thus, pedestrians can easily access the area. Due to the narrowness of streets, the use of cars is difficult there. Nonetheless, cars use this area quite a lot, especially pedestrian streets, mostly as an illegal parking area, when shops close down (fig. 2) and at night (fig. 4b).

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Fig. 2. Kalamiotou Street (a) in the morning, when the shops are open and merchandise occupies the public space; (b) in the afternoon, when shops close down and illegal parking takes place.

2.2. Land Uses Up to twenty years ago, the main land uses of the Commercial Triangle had been commercial on the ground floors and small industrial activities on the upper floors8. The lack of space in the streets forced most of the industries to leave the area8, while commercial activities stayed, although declining, due to the rise of malls in the periphery of the city. Up to the 1970ies fragmentary actions have taken place in the area, concerning street widening

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and the formation of galleries. With greater environmental sensitivity, introducing the rationale of reducing vehicles in the city centre and encouraging the mobility of pedestrians, which is a crucial criterion for sustainable urban mobility 9,10,11,12, as well as preserving cultural heritage, studies have been made to specify land uses, institutionalise pedestrian streets, set guidelines for structures and characterise as preservable a large number of important buildings in the area, ending up in the pedestrianisation of several streets13. Regarding land uses, it has been found out that they remain mostly commercial (66% of ground floor uses), while leisure spaces (cafés, restaurants and street food shops) have started appearing in the area during the last six years (8% of ground floor uses) (fig. 3). Due to the economic crisis that the country is going through and the establishment of malls in the periphery, 17% of ground floors are vacant. Crafts / small industries have almost disappeared, occupying only 3% of the upper floors, while laboratories occupy 8% of the upper floors, as do commercial activities. The majority of upper floors (45%) is vacant, while 16% is occupied by offices. In relation to 20 years ago, industrial activities have decreased dramatically in the area. Commercial use is still dominant, although with many casualties.

Fig. 3. Existing ground floor land uses in the Commercial Triangle.

The trend of leisure spaces is to rise. People who have opened leisure space businesses in the area recently, say that they prefer it, because of the trend of people coming to the area for leisure and also because of the commercial activities that attract people, as well thanks to the existence of pedestrian streets that are perceived by many as spaces that can be occupied for leisure activities. Apart from that, it is an area in the historical centre, underneath the Acropolis, “which needed good quality street food, while one can only find kebabs” as a street food shop owner declared. Commercial shop owners are skeptical about leisure spaces; they think that they occupy too much public space (legally or illegally) (e.g. fig. 4a) and sometimes they blame the rise of spaces of leisure for the closing down of small commercial enterprises. They exhibit fear that they might be displaced by these land uses, as has happened in other areas of Athens. Both commercial and leisure owners agree that they are attracted to this area also thanks to pedestrian streets and squares, which attract people. Residencies make up only 8% of the upper floors, having increased in comparison to 20 years ago, but not so drastically. In some areas, too loud music has been recorded from pubs at night (75-86dB)13, making them incompatible with residencies. Most inhabitants that have been interviewed said that they have chosen this area either due to its vicinity to their work or due to economic or personal reasons. Most of them agree that the area cannot be characterised as a “neighbourhood” (focusing on the lack of shops such as bakery, grocery etc.), while

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they seem satisfied by the existence of public spaces and squares. Some inhabitants with children declare that they are very satisfied by the area’s public spaces, thanks to pedestrian streets and squares, where their children can move safely. Nonetheless, pedestrian streets are heavily, illegally used by vehicles, jeopardising the lives of pedestrians and destroying surface materials. Illegal use of public space is also observed by leisure and commercial activities, which expand the use of public space to larger areas than the ones allowed by the Municipality.

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Fig. 4. (a) Leisure spaces occupying the public space in front of commercial shops at night; (b) pedestrian street transformed into a parking space at night.

3. Sustainability Criteria and Design As can be observed from the collected climatic data from the closest meteorological station to the area (Thission station) in fig. 5, there is a distinctive trend of summer temperature rise, both for minimum and maximum temperatures in the city centre. As temperatures in the city centre have risen due to the expansion of the city, as well as due to the lack of vegetation and the use of impermeable materials with high solar absorptivity14, it is crucial to take actions for curing this effect and lowering summer temperatures. From the field work that has been made, the following sustainability criteria for the design and development of the area have been forward: x Improvement of the microclimatic conditions of the area, through materials, vegetation, shadow (especially on pedestrian paths and stopovers) during the summer period, thus improving outdoors thermal comfort. The choice of materials is also made with the criteria of durability, easiness of repairing, replacement and reuse; x the conservation of existing land uses and the commercial character of the area, with mix of uses; x highlighting the historical elements of the area; x organising space use for pedestrians (crossing and stopovers); x mobility for people who cannot walk or cannot see; x priority to pedestrians and cyclists; x organising the occupation of public spaces from leisure and commercial activities so that they do not interfere with each other and the mobility of pedestrians; x prohibition of vehicles, apart from emergencies.

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Fig. 5. Maximum and minimum summer temperatures from 1908 to 2008, as have been recorded in the meteorological station of Thission (historical centre of Athens). Adapted from15.

Following these criteria, the rationale described in the following section has been put forward. As not all approvals for the implementation of the study have been established up to date, it is not certain whether the rationale of the study will be put forward in practice as described here. Nine streets are turned into pedestrian streets and two streets into low circulation ones, so as to decrease the use of cars in the city centre and increase pedestrianisation; thus pedestrians will have easier access to the area, busting up commercial and leisure activities. Five pedestrian streets and three squares are regenerated, so as to improve their aesthetics, functionality and microclimatic conditions. Commercial and leisure activities are encouraged, but also delimited, by offering limited public space to them. Terra cotta linear designs in the vicinity of buildings are used to define space where commercial and leisure activities can take place, so as not to allow them to disturb pedestrians and act competitively one to the other (fig. 6); by delimiting this space with permanent, simple, linear designs, conflicts arising from vague boundaries of the use of public space can be avoided. Cycling and walking are prioritised, by offering safety to pedestrians. Pathways for blind people and people with kinetic difficulties as well as cycling facilities around the pedestrian streets are designed. Frequent controls will not allow illegal vehicle passage from pedestrian streets; thus, people will be discouraged from using cars in the city centre and instead will use public transport (e.g. subway, buses), walking and cycling, saving energy from transportation; Pathways and places of rest are organised according to shading in summer and sun (where possible) in winter (fig. 6-7); more trees are planted, where possible, especially at the pathways (fig. 6-7) and over places of rest (benches, sitting areas underneath trees). Where the width of streets does not allow planting new trees, pergolas are used where shade is needed (fig. 8). Pergolas are placed only in front of blind facades, so as not to disturb ground floor windows, most of which are shopping windows. Apart from that, large plant pots are placed, so as to increase evapotranspiration in pedestrian streets where no trees or pergolas can be placed. The underground water of the area can water the vegetation placed in the area; thus trees, which offer evapotranspiration and shade in summer are chosen. Cool and natural materials, with low embodied energy are used for covering pedestrian and low circulation streets. The materials that are used (cool flagstones, cool slabs for blind guides, terra cotta and natural, light-coloured stone, as suggested in fig. 6), are easily repaired, replaced and reused, capable of lowering urban temperatures, as suggested by16. These materials, in combination with vegetation increase will ameliorate the microclimatic conditions and thermal comfort of the area, thus are expected to low energy demand for cooling in the buildings of the area. Existing materials from pedestrian streets and squares are stored and reused in other municipal small projects, so as to lower the embodied energy and costs of municipal works. As sustainability also applies in cultural and historical issues, the trace of ancient and medieval streets, shown in fig. 1 a and b, is highlighted with the change of surface materials from flagstones to stone paths (fig. 6). Signs and QRs will offer relevant information to the passerbys and tourists, reminding about the cities under the city;

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Apart from that, LED is used in street lights, so as to lower the energy consumption for street lighting. Recycling bins, with a compressor, which is powered by photovoltaics are placed in the area, so as to encourage recycling and to lower the energy needed for the collection of waste. Special care is given during the construction of the project, so that noise, dust and particles are minimised during the construction according to 17,18,19,20.

Fig. 6. Detail of the rationale of the design and the materials used in the regeneration of the Commercial Triangle.

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Fig. 7. Shading pattern in Polyklitou Street on 22nd June at 12:00 (a) without any trees; the pathway has been placed in the shaded area (a width of 2,20m is shaded); (b) according to the proposal, the shade of the pathway is enhanced with trees; here their diameter is 3,00m, but they are expected to grow larger (shading is estimated with the software ECOTECT).

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Fig. 8. (a) Pergola 1,80m × 5,00m and 3,00m height in front of blind facades for increasing vegetation in the area, as well as shade and evapotranspiration in summer; Agathonos Street on 22nd June at 12:00 (b) without pergolas, where no shading occurs; (c) with the suggested by the proposal pergolas, where shading can occur where blind facades exist (shading is estimated with the software ECOTECT).

4. Conclusions Taking into consideration the climatic, environmental, social, economic, cultural, historical parameters of the area, feasible solutions can be found that can lead to the sustainable regeneration of the Commercial Triangle.

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Despite the crisis that the country faces, it has been found out that existing pedestrian streets have a positive effect, both regarding the quality of the urban environment, as well as the economic sustainability of both commercial and leisure activities in the Commercial Triangle. Although sometimes in conflict these two activities, by strictly delimiting public space which is offered to both of them, in a simple, obvious to all, permanent way, they are expected to work complementarily and not competitively, also allowing public space to the public and not over occupying it for private profit, either for leisure or for commercial activities. Relating the present city with the cities underneath it, by showing ancient and medieval paths on the city floors and by placing QRs with relevant information, more tourists and visitors are expected to be attracted to the area, which could prove beneficial for all stakeholders. Putting into practice elementary sustainability rationale, such as urban mobility focusing on pedestrians, cyclists and public transport, improvement of the urban climate, especially by shading either with trees or with pergolas places of movement and rest, the increase of evapotranspiration with trees and other plants, as well as the use of cool materials can lead to lower summer temperatures and better thermal comfort in the public space. By placing selfcompressed recycling bins, inhabitants and visitors are encouraged to recycle even their small wastes, while the energy for collecting waste is lowered, thanks to the self-compressing technology. By putting forward nonconflicting land uses, the livability of the area is secured. All these actions could lead to a better quality of urban life and a decrease in the energy consumption for cooling buildings, transportation and waste collection. Should this pilot project be successful, it could lead the way for similar regeneration projects with a sustainable agenda. Problems that might arise would also be a lesson for how to put sustainability into practice in the public space. Acknowledgements To the beloved memory of our colleague and friend, Gogo Anagnostopoulou, whose contribution with creative discussions and viable information has been vital to this project. May she shine, wherever she is.

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