Adaptable Morphodynamics

ADAPTABLE MORPHODYNAMICS

MSc CANDIDATES

Silvia Daurelio

Maria Fernanda Chaparro

ADAPTABLE MORPHODYNAMICS

MSc CANDIDATES

Silvia Daurelio

Maria Fernanda Chaparro

ARCHITECTURAL ASSOCIATION SCHOOL OF ARCHITECTURE

GRADUATE SCHOOL PROGRAMME

PROGRAMME:

TERM:

STUDENTS:

SUBMISSION TITLE:

COURSE TITLE:

COURSE TUTORS:

Emergent Technologies and Design

03

Maria Fernanda Chaparro, Silvia Daurelio

Adaptable Morphodynamics

Emergent Technologies and Design - Master of Science

Michael Weinstock, George Jeronimidis

Evan Greenberg, Mehran Gharleghi

SUBMISSION DATE:

19.09.14

DECLARATION:

“I certify that this piece of work is entirely my/our own and that any quotation or paraphrase from the published or unpublished work of others is duly acknowledged.”

SIGNATURE:

Maria Fernanda Chaparro Silvia Daurelio

Michael Weinstock

George Jeronimidis

Evan Greenberg

Mehran Gharleghi

Wolf Mangelsdorf

EMTECH STAFF

Director Director

Studio Master

Studio Tutor

Visiting Professor

ACKNOWLEDGEMENTS

We would like to express our gratitude to Michael Weinstock and George Jeronimidis, whose expertise and sincere guidance enabled us to progress in our personal and professional development, leading us to explore new dimensions of the design. We would like to thank also Evan Greenberg and Mehran Gharleghi for providing us with constant support and inspirations. Finally, we would like to thank our families, friends and all people involved in this phase of our life, for their patience, encouragement and help as well as all our Emtech colleagues.

PERSONAL CONTRIBUTIONS

This year in Emtech allowed us to explore new theoretical and experimental fields of architectural design through use of a consistent and scientific method. In particular, during our dissertation we gained new expertise and skills in the field of the parametric design, with particular focus on the computational evolutionary techniques applied to architecture. Our mind was opened to innovative design solutions for complex environmental and social contexts and we learned how to run environmental simulations at both the urban and building scale, in order to get a clear insight into causes and effects of the design process at each stage. Finally, the cooperation and exchange of ideas and expertise within the various teams allowed us to achieve shared goals.

MORPHODYNAMICS

Morphodynamics is defined as the study of the three ways of interaction of physical, informational and geometrical processes that influences the changing form, shape and structure of living cells, tissues and organisms

(Vijay Chickarmane, 2010).

table of contents

4. SELECTED PATCH

- Site Analysis

- Rooftop villages

- Analysis of Existing Urban ventilation

- Conclusion

5. DESIGN DEVELOPMENT

- Overview

- Environmental factors

- Social & architectural aspects

- Connectivity

6. EXPERIMENTS

- Strategy’s parameters

-

-

7. EXPERIMENT 2: BLOCKS AGGREGATION SCALE

Adapable Morphodynamics addresses the development of complex high density urban systems over space and time. Building morphologies can be conceived as living organisms that change in form, shape and structure through the interaction of physical, informational and geometrical processes.

This research focuses on density, environmental quality and spatial identity. These studies are extended to present-day Hong Kong and addresses a design system that aims to reinterpret spatial logics, connected with local socio-cultural attributes, into a set of rules and code for an “intelligent densification”.

From the data gathered, two strategies are developed in parallel and as they become more defined, they begin to inform one another until a holistic urban approach is developed. Urban porosity and Urban growth at different scales (neighbourhood, plot and building) become the key design tools to achieve environmental performance, in terms of urban ventilation, housing public programmes, and maximizing pedestrian and bicycle accessibility for all people through a fluid mobility network at ground

and multiple layers of connectivity.

Existing building morphologies are transformed computationally into porous organisms and are used to construct accurate models of growth for regaining the lost demographic pressure. Multi-objective evolutionary algorithms are employed to generate a complex urban design model. This is characterized by the emergence of public green areas, integration of sociocultural amenities within the existing building morphologies and by generation of a comfortable outdoor microclimate, at different operational scales. The improvement of the well-being of the urban population could be achieved through a spatial approach based on principles of social inclusion, especially in the most deprived areas of the patch, characterized by illegal and informal settlements, known as “rooftop villages or sky-slums”.

The main target, in the long term, will be to develop an “urban intelligence” that takes into account the mutual relation between demographic demand, site constraints and the potentialities and limitations of the architectural targets.

1. introduction

1.2 Design Objectives

1.3 Design Strategy

1.1 Hong Kong’s Overview

Hong Kong’s intense urbanism is the outcome of a continual fluctuation of people, goods, data and services. The city’s compact footprint and rapid densification has led to the city’s vertical growth. This has defined Hong Kong’s skyline and has directly affected environmental and social conditions that challenge the contemporary urban planning of the city.

The city is part of the special Administrative Region of the People’s Republic of China, located at the mouth of the Pearl River Delta on the coast of southern China. Its strategic

geographical position as a gateway between the East and West has made it an attractive centre for international trade, which has contributed to the rapid economic and population growth. It was first established as an entrepôt port and naval base, and has positioned itself as an important manufacturing and financial centre. In the 1950s, Hong Kong’s rapid industrialisation was driven by textile exports and other expanded manufacturing industries that resulted in a massive migration of refugees from inland China looking for better opportunities.

Source:

“Architecture Of Density” (the Outside Volume Of Hong Kong Inside/outside), Michael Wolf, 2013

Fig.1.1: Architecture of density, Hong Kong

As the population grew and labour costs remained low, a high demand for housing increased land prices. The Chinese population had dealt with crowded conditions for years, where the average housing space was 3.5m² per person: 4.9m² in small cities and 2,2 m²in big cities. Migrants were living in poor and compact spaces, but it wasn’t until a fire broke out in squatter settlements leaving around 53.000 refugees homeless that the government became more conscious regarding the low housing standards and the surge of the immigrant population in the city. Following the incident, the government launched

a public housing programme to introduce the idea of “multi-storey buildings” for the immigrant population, thus commencing a mass public housing project, providing affordable homes for those on low incomes.

The city went on to develop its economic and financial prosperity via a mixed economy of hightechnology products and small industries which are reflected in the financial towers along the coast, juxtaposed with the crafted-base informal economy made up of numerous small household companies. Hong Kong is a city of constant

change, capable of adapting and fulfilling the challenges of becoming a global city.

Fig.1.2: Hong Kong, weather, humidity, rain fall, wind force

Source: http://www.weather-and-climate. com

Population

and

Kong’s Fresh Water use (2011) *

Hong Kong (2011)

Fresh water Salt water

Showering Tap water Washing machines Others 43.3% 46.6% 9% 1.1% 1971 1970 1981 1980 1991 1990 2001 2000 2011 2010 Year Hong Kong population Hong Kong water comsumption 8 7 6 5 4 3 2 1 0 P op ulat ion (m illion s) 1,00 0 900 800 700 600 500 400 300 200 100 0 Water consumpt ion (mcm/year) 90 litres for Flushing

The build out of the city and its tropical climate has triggered several environmental problems, such as urban heat island effect, high levels of pollution and a shortage of water. Temperatures have increased during the last decade in urban and rural areas by 0.6ºC and 0.2ºC respectively; thus high temperatures of around 28ºC to 31ºC, high levels of humidity around 80 per cent, and low wind ventilation at ground level are observed during the summer months. These conditions unmeet the thermal comfort of the outdoor environment, making it difficult to enjoy

any outdoor activity, even walking. Short-term solutions have been applied, such as the use of air conditioning on escalators and the pedestrian secondary layer.

One of the biggest impacts of climate change in Hong Kong is a shortage of water. Due to urbanisation, water resources have been diminished, with 20 per cent of the water supply currently coming from water catchments and 80 per cent of the water being imported from the Dongjiang River. The river is shared with five

Total = 214.7 litres

Fig.1.3: Hong Kong, water consumption

Source:

other cities in the Pearl River Delta Region under the Dongjiang Basin Water Resources Allocation Plan. The plan has a maximum usable water resources limit and is unlikely to have surplus capacity in the future, due to the warmer climate. The rapid growth of population means greater water consumption, thus increasing domestic demand.

Hong Kong’s area of 1,104km² has the world’s highest percentage of urban green space; over 80 per cent is comprised of mountains and wetlands and the other 20 per cent of the territory is left for the development of the urban tissue that hosts a population of 7,184,000 inhabitants. The city is built on steep slopes and is therefore facing one of the major challenges of construction, due to landslides and unsuitable terrain for building. The high demand for land has driven Hong Kong to use the majority of the suitable land for construction, creating a contrast between the constructed and open areas.

The city’s high density and constant demand for construction has only left a relatively small area to act as public space for the city’s population; the average public space per person in Hong Kong is 2m², while in Western cities, such as London, the average is 8m². The shortage of spaces for social interaction has led Hong Kong inhabitants to re-define what public space is, so that streets, market areas and shopping centres become areas where social activities take place.

Source:

http://www.cn.hdscreen.me

Fig.1.4: Topography and High density, Hong Kong

The high density has had a significant impact on the development of the city, in which proximity becomes a necessary condition for sustainability. A full range of activities, such as residence, shopping, working and leisure, all happen in the same place and at the same time; this is only possible thanks to the complex that allows this intense dynamic of interaction to happen.

Hong Kong has proven that a high population density can be viable through the provision of effective public transportation systems and infrastructure that allows pedestrian journeys through footbridge passages: a ‘secondary

hong kong’s overview 1.1

layer’ that connects corporate lobbies, hotels, shopping malls and transportation hubs with the urban fabric.

The wide range of possibilities for transportation, such as ferries, trails, trams, buses, and escalators, encourage the population to use public transportation and opt for pedestrian journeys. The effectiveness of this model shows that only 4 per cent of the journeys are made by car, 44 per cent by walking and 52 per cent by public transportation.

Fig.1.5: Map Green areas and Method of transportation, Hong Kong

Source: LCE Cities, Urban Age Cities

Compared, 2011

Source:

“The Making of Hong Kong,from vertical to volumetric”, Barrie Shelton, Justyna Karakiewicz and Thomas Kvan, 2010

The verticality of the city and the intensification of usages bring a concentration of activities and modes of movement across the city; several levels of connectivity that extend to other buildings have created the largest secondary pedestrian layer in the world, with over 800 metres in distance that elevates over 135 metres from the ground floor. It is not only used as a circulation, but also plays an important role as public space where leisure activities take place.

The need to move through congested areas and across challenging topography has led to inventive

solutions and opportunities for accessibility on different floors of the buildings, and the proposal of three-dimensional connections from where the ground floor extends, like a series of mid escalators, has been suggested to ease the movement of the pedestrian population in steep areas. This continuity of connection would allow the permeability of the buildings and increase the flow of people through commercial and market spaces.

Hong Kong’s high-density network model is coherent to the one suggested by Jane Jacob

in 1961 when she challenged the planning world by suggesting “more and shorter streets to give more choice, convenience and vitality to an area: it would give more route options, and more strategic crossing points and corners; induce more stopping and meeting points; and create more favorable location points for the generation of economic and other activities” (Jacobs, 1961).

Fig.1.6: Topography, secondary layer, podium diagram, Hong Kong

Source: http://www.wikipedia.com

Fig.1.7: Footbridge , Connection secondary layer and podium, Central ICF , Hong Kong

Data about the climatic conditions of the city will be collected to focus on specific urban environmental problems, such as high heat island intensity and serious air pollution due to a lack of natural ventilation in the urban clusters.

The application of an evolutionary urban design strategy will focus on the emergence of urban attractors, which will be able to interconnect with the different parts of this existing urban fabric and enhance its spatial, social and environmental qualities. Urban inclusion will be followed in order to minimise disruption and maximise benefits for inform al and s elf-built

Optimised building morphologies will provide the existing urban fabric with social and cultural amenities in critical points of interactions.

They will be refined through the integration of greenery, a porosity system including airflow, and a fluid pedestrian circulation at multiple levels. Using greenery solutions to absorb pollutants, mitigating the urban heat island effect through the reduction of humidity levels, and creating global urban air ventilation will be important environmental goals to enrich spatial qualities.

Economy

Wetland ROUGHNESS STRATEGY

Urban STRATEGY POROSITY STRATEGY ENVIROMENTAL LOGIC SOCIAL LOGIC EMERGE CONNECT

Increase

This dissertation applies an evolutionary urban strategy through a porosity and roughness system that will affect the existing morphologies of the buildings. Adaptable morphodynamics aims to optimise the existing urban tissue in order to create a symbiotic relationship between the built environment and the site conditions.

Morphodynamics is defined as the study of the three ways of interaction of physical, informational and geometrical processes that influences the changing form, shape and structure of living cells, tissues and organisms (Vijay Chickarmane, 2010).

The improvement of the environmental conditions and social inclusion are the main drivers of the experiments. These factors aim to enhance the qualities of a vibrant high-density tissue and respond to the site’s deficiencies to reduce the ecological footprint and provide better living conditions. The design strategy will attempt to impose minimum disruption in order to maintain the high density of the patch; this will be achieved by the relocation of at least 40 per cent of the population.

2. domain

2.1 High Density Cities

2.2 Concept of Public Space

2.3 Envirnmental Problems in dense urban tissues

2.4 Case Study

Source: http://wwwfritzmuellerphoto. com

Fig.2.1: Urban Sprawl: Calgary, Alberta

Source: http://www.planetizen.com/ node/60424

high Density cities 2.1

The question of how to approach a high-density city model has always been open for debate, In some cases High Density is referred to as a negative quality of the cities because of their impact on the environment and the damage it causes to land quality. Cities consume and produce disproportionately large amounts of resources and green house emissions; American and Australian cities generally have greater surface area than European and Asian cities. The ecological footprint of the American city is typically 30 times that of the physical city because of the amount of area that it takes to build up the city, therefore small footprint cities might have more intrinsic potentials to become less resource consuming than more sprawling cities with sparser living and building patterns.

Fig.2.2: High density, compact footprint, Singapure

In the specific case of Hong Kong, Hui concludes “Hong Kong’s High rise compact forms bring real benefits to the city by virtue of more compact distribution area and far less energy consumption for travel compared with almost every other city in the world”. (Kenworthy, 2008). However, he also points out some potential disadvantages of high density living: it can create road and micro climate conditions that result in more, not less energy use – for instance, cars consume considerably more fuel in slow moving traffic and homes use more air- conditioning when contained in a city of massive buildings forms that block the natural flow of air. (Hui, 2001)

The advantages of the high-density city are the effectiveness of public transportation, which result in more journeys on foot and discourage the car as a method of mobility. A denser urban living contains buildings that host a large mixture of usages allowing homes to be serviced from less extensive infrastructure. By the interaction and dynamism of this usages it also creates a greater concentration of people meaning greater range of social, health, recreational and other services that can be offered in closer proximity.

This has a direct impact on lowering the costs of constructing and managing services.

It is the interaction of usages that bring vitality and intensity to a place through multiple scales of connection from local to global. Then it is not only the density that is in control of the dynamics and interactions of a place, but the physical configurations and the way they are connected, that can make a high density city more sustainable. Christopher Alexander, reinforced Jane Jacobs notion of the city as “organized complexity” he states: “The city is not a Tree”, in which he used the ven diagram to illustrate the nature of relationships between urban activities, his argument was: that urban services and facilities are symbiotic and cannot exist in isolation from each other. A connection between different activities means more frequent use for all of them: They interact by virtue of their proximity and the form of spaces that join and lead to them. (Alexander, 1966)

Other high-density cities such as London and New York have developed a different form of urbanism; London’s urban sprawl consist in

Source:

"Cities Without Ground: A Hong Kong Guidebook", Adam Frampton ,Jonathan D Solomon , Clara Wong, 2012

a low-density living and high-density working areas, this creates different dynamics in which the lack of integration will result in a larger amount of time commuting, while New York has successfully achieved a balanced integration between living and working environments reducing commuting time. On the other hand, Hong Kong is the most integrated global city in terms of connectivity, which allows a complex interaction of usages and activities within the city.

Transport infrastructure is a critical driver of urban form, enabling the centralization of economic functions and the accommodation of a growing population. Without public transport, space-hungry motorways dominate, resulting in more sprawl and congestion. The oldest and most extensive metro, bus and rail systems are in London and New York, creating high levels of accessibility. Hong Kong’s younger metro network extends to approximately and because of its constrained topography has developed a more efficient and affordable public transport. (Cities, 2011)

Fig.2.3: Central Hong Kong, Exisiting secondary layer

high Density cities 2.1

Pilmico Upper East West Kwoloon

London Population 8.308 million Area 1,572 km² Density 5,285/km2 Green Public space 38.4%

Hong Kong

Population 7,174 million Area 1,104 km² (18% buildable) Density 6,516 pp/km2 Urban Public space 6%

Fig.2.4: Residential Density and method of transportation,global cities.

Source: LCE Cities, Urban Age Cities

Compared,2011.

Adaptable Morphodynamics

A comparison between the global cities regarding important aspects for living conditions, highlight Hong Kong’s main deficiencies. As a contrast to other global cities, Hong Kong’s public space (in the urban area) is only 6 per cent compared to cities like London and New York with a 38 and 14 per cent respectively, The wealth gap, lack of public space, poor living conditions, long working hours and environmental problems reveal the instability of Hong Kong’s regulations towards the wellness of its population.

The development of Hong Kong as a leading

manufacturing city defined living standards and conditions that have still remained in the urban culture. The city developed in order to meet an economic and industrial target undermining the standards of living conditions of the population. High density understood as overcrowding, in a city with a shortage of public space, has a great impact on social and mental health, as an example; young population being raised indoor, with no social interaction.

It is important to value the challenges that high density cities brings within, a great complexity

of vertical relations that can generate patterns of living the city; but this can only be achieved through a balance and a structural logic established by the understanding of the context and cultural background.

Source: http://www.citymayors.com/ statistics/global-cities.html.

Fig.2.5: Hong Kong, General aspects performance.Ranking and comparsison global cities.

WHAT IS A PUBLIC SPACE?

Urban planners have historically defined a “public space” as the collection of publicly owned and managed outdoor spaces, including streets, squares, parks, and similar informal recreational areas, to which every member of the community has free access, regardless of his or her social and economical status. Accessibility and circulation are not the only elements that characterize a public space, but the functions directly connected to social and cultural implications are relevant factors as well.

In human history, the idea and form of public space arose and developed in relation to needs, values and characteristics of specific times, places and populations’ culture. William H. Whyte, an American sociologist and urbanist, states, “Public spaces as expression of human endeavour and artefacts of the social world are the physical and metaphysical heart of the cities, thus providing channels for movement, nodes of communication and common ground for cultural activities.” (Whyte, 1980).

In general, the term “public space” is directly associated to social and public life, and reflects Western habits of civic activities that take place in squares, parks and similar places, showing the freedom of speech and association that characterizes our society. As a consequence, it is often ignored that in other contexts social and public activities can often occur in a nonpublic space and through different channels of interaction, or even that the same idea of public space can completely mismatches the mainstream view. For example, in China’s old cities open space and nature are broken into smaller pieces and evenly distributed according to a human scale and a horizontal layout, while Western cultures group open space into bigger

pieces, distributing it through important nodes in a vertical oriented city. The enclosing of spaces characterizes the Chinese perception of the space, seen as series of enclosed worlds.

(Nijveldt, 2013)

As a consequence, several and various factors, such as people’s lifestyle, modes of social interaction or generation gaps, need to be analyzed to get a clear insight into the nature that shapes public spaces. Not only is it important to put in relation the characteristics of a public space with the individual and collective values that are performed in it, but it is also crucial to define the seasonal and cultural rhythms associated to a specific place. In addition, it seems that the nature of a public space is clearly related to local climate conditions, accessibility and walkability, but it has also a connection with the urban transformations brought by the integration of cities into the global scale.

To conclude, this section will explore the concept of public space from a non- Western perspective, in order to get a clear insight into the contrast that today shapes the Asian cities, divided between a local culture, which is linked to a traditional past, and a globalized emerging financial power. With this in mind, the main questions to be answered are: “What form has the public space in the age of globalization?”, and more important, “How has the meaning of public space changed over time in China and Hong Kong?”

Concept of PUBLIC space

Source: http://photomichaelwolf.com

PUBLIC SPACE AND GLOBALIZATION

Capital flows and business expansions have played a significant role in changing and shaping the structure of contemporary cities, activating a process of compression and densification of the living space of inhabitants in the urban space. Landmark office buildings, shopping malls, hotels and massive transport infrastructures took over large portions of the global cities, depriving city-users of concrete spaces of everyday life, both private and public, and pushing the phenomenon of urban densification without no-control.

This intense and fast urban growth has often generated examples of high density residential districts that are characterized by poor housing and lack of services and facilities, which are the result of a physical vertical compression of the space. Moreover, as a consequence of the massive densification of the cities, significant environmental problems, such as an increase of temperature and pollution or lack of urban ventilation, have been negatively affecting the quality of urban cityscapes and its people’s lives.

In the East Asian metropolises, such as Hong Kong, Tokyo and Shanghai to name a few, the effect of globalization on the living environment has evolved at a faster pace and has caused extreme transformations in the last two or three decades with respect to that of Western global cities.

THE CONCEPT OF PUBLIC SPACE IN CHINA

More than anywhere else, the Chinese public spaces are full of prohibitory signs and not everyone is allowed to enter. China is practically a one-party state with an authoritarian political system where the government exercises a strict control over the population. (Orum, 2009)

As a result, the lack of adequate public spaces have driven Chinese people to use the urban space in a creative and intense way by transforming it according to their needs and their idea of public display. It is important to remember that streets have always been the main form of non-designed public space in

Chinese cities, being used for different purposes, including an extension of one’s own private home space. Streets can be seen as lively and chaotic containers for informal activities that have indirectly contributed to creating publicity in the urban space.

Indeed, “disorder” is a word that can define with a positive connotation the authentic essence of the Chinese everyday public space, meant as a creative mess that shapes narrow and crowded spaces. For example, it is crucial to take into consideration the value of traditional street markets in the Chinese culture in order to understand what public space means for Chinese people. Not only do outdoor markets add colour and energy to the street scene, but they also reflect the identity of local communities and their way of living socially. The purpose of street markets is not merely commercial, but also to provide the urban environment with diversity and thus encourage a social interaction, which has been repressed in other places.

Fig. 2.6: Compression of the space -Poor Housing, Hong Kong

Source: http://photomichaelwolf.com

Concept of PUBLIC space 2.2

Source: http://photomichaelwolf.com

Adaptable Morphodynamics

Fig. 2.7: Informal seating arrangements

Fig. 2.8: Informal seating arrangements

Concept of PUBLIC space 2.2

Source:

THE CASE OF HONG KONG

In Hong Kong the form of the urban space has been quickly modified by the desire to achieve an international reputation and a cosmopolitan character similar to those of Western global cities, such as New York or London. A force of timespace compression has been activated in Hong Kong’s urban landscape, giving two version of the same city, respectively defined by a global capital accumulation and a local compression that collapse to accommodate urban densities. As a result, this process has created a new social structure that is defined by striking social contradictions between international business people and a huge population of low-income people.

In addition, monumental vertical buildings have become an emblematic aspect of the economic success of Hong Kong, but they occupy a great portion of the available land and have gradually consumed the local identity of the place. As a consequence, this dual spatial and temporal

compression has taken over the existing public space to make room for housing, and it has produced hyper-densities areas in which old communities are relegated to sandwiched and jam-packed spaces. (Huang, 2004)

The lack of adequate public recreational areas encouraged the city-users to take over existing urban sites and transform them into self-made urban spaces for a series of social activities. Pieces of cities are injected with new functions and redefined as an alternative public domain. Especially during the weekend, empty streets and deserted plazas of private multinational companies in Hong Kong Island have over time become informal gathering places for lowincome workers, fulfilling the collective desire of public space in the contemporary city.

A significant example is the HSBC Bank, occupied by Philippine immigrant enjoying their day-off. The structured urban layout of the

financial district is attacked by a spontaneous and disordered self-expression of the public sphere, which provides the space with new programmatic usages and significance. Most of the social activities that are forbidden or reputed “undesirable” in the few official public spaces happen in this empty square on Sundays. Here people meet and spend their spare time by sitting on straw mats, playing card games, hawking goods from home, and even getting haircuts and manicures. Lisa Law, an Australian researcher in Urban Studies, states in her article Defying Disappearance: Cosmopolitan Public Spaces in Hong Kong, that “Central is a ‘multicoded’ landscape where shoppers, tourists, office workers and migrant groups are ‘reading’ and ‘writing’ different languages in the built environment”.( 2) This means that not only is the concept of public space in Hong Kong linked to people’s cultural background, but it also changes according to the social differences.

Fig 2.9: Alternative public space in Central Hong Kong, HSBC Bank’s square - Philippine immigrants enjoying their day-off

http://www.asianurbanepicenters. com

(2) Lisa Law, Defying Disappearance: Cosmopolitan Public Spaces in Hong Kong, Carfax Publishing, 2002, Urban Studies, Vol.39, No.9, pp.1625-1645

STREET MARKETS AND SHOPPING MALLS

In Hong Kong the increased homogeneity of the urban space brought by the global culture has gradually diminished the authentic way of living the public space by the city-users. Some critics claim that Hong Kong’s citizens lost their interest in public space because of their hasty lifestyles and under the influence of the traditional Chinese culture, which did not allow people to gather publicly. On the other hand, others assert that before the British colonization, Hong Kongers had already associated the idea of public space to social interaction. For example, traditional markets (hui), ancestral temples (pinyin) and open areas in villages were all reputed important places for the day-to-day social life.

In fact, commercial streets and street markets have always been a significant form of public space for the local Hong Kongers, an example of their unique way of interacting socially and culturally. Today, most of these places have been slowly replaced by shopping malls, considered

an optimal solution to regenerate degraded parts of the city and develop the tourism industry at an international level.

Bearing this in mind, the question is: what is the new form of public space in Hong Kong? The adoption of westernized customs and the deterioration of outdoor environmental conditions, due to the massive urban densification, caused the decline of the traditional public space and increased the demand for air conditioned indoor spaces, such as shopping malls. The diffusion of commercial centres in the city since the 1980s marked the beginning of the decline of the traditional and collective concept of public space. In the late nineties, the amount of public space per each Hong Kong’s inhabitant was only 1.5 square meter, and in some of the most densely populated district of the city, such as Mongkok, each resident has only 0.5 square meter of public space.

Source: http://manfredgruber.net

Source: http://hk-magazine.com

Fig 2.10: Apliu Street market, Sham Shui Po, Hong Kong

Fig 2.11: Apliu Street market, Sham Shui Po, Hong Kong

Concept of PUBLIC space

Source: http://theprotocity.com

Although malls allow free access to users and house daily social activities, such as shopping and eating, they actually act as pseudo-public spaces because of their privatization and the restricted freedom to conduct a variety of activities. A curious aspect of this diffuse phenomenon is that the malls of Hong Kong are not simply spaces to go shopping, but they represent a point of public meeting and leisure walking for the community. Their internal layout of corridors and plazas, the thermal comfort and the wide range of facilities available emulate shape, characteristics and functions of the outer urban spaces that the real city cannot offer to its inhabitants. These buildings concentrate so many functions onto a small piece of land and differ from the North American counterparts, which are self-contained on the outskirts of the cities. Most of them are connected through public transport systems, enabling the user to walk indoors all the time.

In contrast, some people may argue that the government has provided the community with sufficient public space. There are a number of sizable recreational parks in Hong Kong,

including Kowloon Park, Victoria Park, Hong Kong Park and the Hong Kong Zoological and Botanical Gardens. Despite the theoretical publicity of these place, in practise a wide range of social activities, such as bringing animals to the parks, riding bicycles, roller-skating, flying kites, bringing food to eat, running, walking on grass and lying on benches are prohibited. (Lo Ka Man, 2013)

Fig.2.12: Yan On Building in Mong Kok (1965), Hong Kong - It is one of the earliest examples of shopping mall, a single corridor that create a public pedestrian thoroughfare.

Source: http://www.hkpsi.org

A SUCCESSFUL MODEL OF PUBLIC SPACE IN HONG KONG

As stated above, cultural, environmental and physical factors have a great influence on the perception that people have of public space. It is crucial to bear in mind that values of communities change and what that can be considered a successful example of urban space for a culture may not fit well in another place. For instance, Western cultures may like to be exposed to the sunlight in open spaces, but is this true in the East Asian context? Overall in Hong Kong, people, especially young women, may prefer to keep their skin white and spend their spare time in air-conditioned shopping malls, characterized by thermal comfort and cleaner air. These reasons make it easier to understand why the majority of the existing outdoor public spaces in the city are not able to attract local people.

As a consequence, the design of a public space should take into consideration what are the needs of the community and what external factors play a crucial role in distinguishing that specific context. Now, it can be deduced that

in Hong Kong an attractive and well-designed open public space should provide its users with comfortable temperatures, shaded areas and various range of activities for different age groups. It is necessary to think about how people would use a space that can fully belong to Hong Kong’s context.

A successful model of new public space in Hong Kong is represented by the Kwun Tong Promenade, situated at the Eastern part of the Kowloon Peninsula. It opened in 2010 on an industrial stretch of waterfront facing the runway of the old Kai Tak Airport, and is 200 metres long, but the plan is to continue expanding it. Water vapour is released from vents inside the boardwalk of the multi-purpose plaza, offering visitors a refreshing way to cool down, especially in summertime. This space is defined by a mixture of green and water and it contains a series of new recreational facilities that stimulate people to spend time outdoors.

To conclude, it can be supposed that in the congested and hyper-dense Hong Kong a network of pocket, vibrant and equally distributed open spaces could probably enhance the global quality of the urban environment, rather than localized big public spaces.

Fig.2.13: Kwun Tong Promenade, Hong Kong- Public space can encourage social interaction

Concept of PUBLIC space 2.2

HONG KONG STANDARDS FOR PROVISION OF OPEN SPACES

In the urban areas, including the Metro Area and the New Towns, the standard for provision of open space is a minimum of 2m2 per person, apportioned as follows:

(a) a minimum of 1m2 per person for District Open Space

(b) a minimum of 1m2 per person for Local Open Space

DISTRICT OPEN SPACE

District open spaces are medium-size sites (where possible at least 1 ha) which provide facilities for core activities and for passive recreation to meet the needs of a district population.

LOCAL OPEN SPACE

Local open spaces are smaller sites (where possible at least 500m2 in the urban areas) which are more passive in nature and provide sittingout areas and children's playgrounds to serve the neighbourhood population. For local open space serving a larger neighbourhood, some active recreation facilities may be provided. (3)

Fig. 2.14: Hong Kong FloraMaximazation of private space by creating a natural environment on the facades of houses

Source:

http://photomichaelwolf.com

Fig. 2.15: Hong Kong Flora -People’s imaginative way of integrating nature with the city

Source: http://photomichaelwolf.com

(3) http://www.hkpsi.org/eng/publicspace

DEFINITIONS

OPEN SPACE

Meaning any land with the minimum of building structure which has been reserved for either passive or active recreation and provides major or minor recreational facilities, which may be of local or district significance, which is for the use and enjoyment of the general public. This includes parks and gardens, playground/playing fields, promenades, pavilions, sitting out areas, pedestrian areas and bathing beaches. (3)

PUBLIC SPACE

It can be defined as an area where everyone, regardless of his or her background, can enter without pre-requisite, such as an entry fee. Typical examples include public squares, parks, streets, public libraries, street markets, and country parks, etc. (3)

SEMI-PUBLIC SPACE

The term "semi-public space" refers to places that appear to be public spaces but they are in fact privatized spaces. Despite a lot of social interactions and even public life are going on in these pseudo-public space, they are not truly public spaces as they do not always fulfil one fundamental spirit of public space, that the entry be free for everyone. (3)

PRIVATE SPACE

It is defined as a space which is owned by particular groups or individuals but not the community, and is meant for private use. The entry of certain people can theoretically be restricted by their owners. (4)

SEMI-PRIVATE SPACE

It is defined as a space that is access controlled and accessible to residents and associated people only. These spaces are not really private since they’re shared, but because they’re usually inaccessible to outsiders, they’re not really public either.

(3) http://www.hkpsi.org/eng/publicspace

(4) http://waua.wordpress.com/tag/semi-private-space

Fig. 2.16: Diagrams, Typology of spaces

Environmental problems in dense urban tissues 2.3

The built environment is not just the collection of buildings; it is also the physical result of various economic, social and environmental processes, which are strongly related to the standards and needs of society. Cities are integrated systems that facilitate the delivery of a wide range of services and activities. Synergies among these elements generate stress in the built environment. (Santamouris, 2001).

Indeed, not only has the rapid development of cities increased enormously the population’s density, but it has brought about a lot of negative effects on the global environmental quality,

such as heat stress, worsening of air quality and acoustic pollution, to name a few. It seems clear that the relationship between climate change and the urban system is extremely important to understand causes, effects and solutions for the main environmental issues that negatively affect the quality of life in our cities.

The urban environment has been modified by the process of urbanization and industrialization, causing an increase in the number of buildings at the expenses of open spaces and greenery. As a consequence, today the majority of high density cities are characterized by a change in

the heat balance with respect to the surrounding non-urbanized areas, called “Urban Heat Island Effect”.

Environmental conditions. Urban

Definition of UHI Effect

Environmental problems in dense urban tissues 2.3

“It is defined as the rise in temperature of any man-made area, resulting in a well-defined, distinct "warm island" among the "cool sea" represented by the lower temperature of the non-urbanized surroundings” (Perez Arrau C., 2011)

Mean UHII By TPU in hot seasons ( June - September, 2001-2009).

- Urban canyons: narrow arrangement of buildings

Definition of UHI Effect Causes

Urban Heat blocked by buildings

Mean UHII by TPU in hot seasons (June-September, 2001-2009)

“It is defined as the rise in temperature of any man-made area, resulting in a well-defined, distinct "warm island" among the "cool sea" represented by the lower temperature of the non-urbanized

High: 7.5 T > 28 ํC - Wind speed = 11 km/h

Medium: 3.67

Low: 1.35 T < 28 ํC - Wind speed = 33.6 km/h

-

Urban Heat blocked by

New Territories

- Decrease of vegetated areas and low wind velocity

-

Kowloon

Hong Kong Island

Lantau Island

Lamma Island

Mean Urban Heat Island Index (UHII) for Tertiary Planning Units in Hong Kong (2012)

Mean Urban Heat Island Index (UHII) for Tertiary Planning Units in Hong Kong (2012)

Source: Mean Urban Island Index (UHII) for Tertiary Planning Units in Hong kong, 2012

URBAN HEAT ISLAND EFFECT (UHI)

According to Sue Grimmond, a world leading expert on urban climates at Kings College London, the “Urban Heat Island Effect (UHI)” is a phenomenon whereby temperatures tend to be warmer in urban than surrounding rural areas, particularly when it is calm, clear and at night. On average in cities temperatures are one to three degrees centigrade warmer, but on occasions may be as much as 10 C warmer.

CAUSES:

- “Urban street canyons” , defined as places where a narrow street is surrounded on both

sides by very tall buildings, usually skyscrapers. The height and the narrow arrangement of buildings creates a “wall effect” that blocks the urban air flow, especially at the street level, and they also reduce the sky view factor.

- Building materials , such as concrete, bricks, asphalt, etc., have non-reflective and water resistant properties. They absorb and store a great quantity of incident radiation during the day, and slowly release it as heat at night.

- Decrease of vegetation areas and high surface covers, such as parking areas, buildings plots

-

- Buildings material with low reflectivity

and roads, lower the amount of water sources and limits the dispersion of the heat through the process of evapotranspiration. As a result, there is an increase of air temperature on the buildings’ surfaces and in the atmosphere.

- Human activities also release large quantities of waste heat in the air due to air-conditioning and refrigeration systems, vehicular traffic, industrial processes, etc. A direct consequence of this phenomenon is also the production of air pollutants and dust that create the well-known “Dust dome effect”, keeping the heat in the lower layers of the atmosphere.

Fig.2.19: Causes of UHI Phenomenon

Fig.2.18: Mean UHII By TPU in hot seasons ( June - September, 2001-2009)

Environmental problems in dense urban tissues 2.3

Negative Effects of UHI Phenomenon

Uncomfortable Warm Environment

- Impact on Human comfort

- Spread of diseases

- Mortality

Dust Dome Effect

Data for UHI in Hong Kong (2012)

- Air pollution

Case Study: main solutions

(1) SHANGHAI and SINGAPORE

- Skyrise Greenery Incentive Scheme

Evaporation

Evaporation

Cooling effect

Green-roofs

- High Electricity Consumption

Green Facades

(2) STUTTGART, GERMANY

- Green Aeration corridors

- Increase Greenhouse Effect

Increase of Temperature from Location 1 to Location 2

urban margins

Increase Use of Air-conditioning between 2 and 6 �C /every km

urban green areas

urban channels

between 2 to 3.2 C

between 2.3 to 3.5 C

city centre

hottest urban spots

hottest urban spots

Natural wind patterns

Air-flow exchange

T cooling effect

Better Air quality

(3) MELBOURNE

- Urban Wetlands

Water in the urban environment

Evapotranspiration

reduction of daily heat stress

IMPACTS:

- Health and welfare of inhabitants can be seriously compromised by the thermal discomfort due to high temperatures, causing physiological disruption and diseases, such as heat syncope and heat stroke, which in some cases can be fatal.

- Increased Energy Consumption for cooling (i.e. refrigeration and air-conditioning) indoor spaces intensifies the emission of greenhouse gases and other pollutants, such as sulphur dioxide and carbon monoxide, into the atmosphere, and

consequently it leads to higher levels of air pollution. Moreover, an increase in the energy demand could raise the prices for inhabitants and governments.

- Water quality can be compromised by storm water, heated by the high temperatures of urban surfaces. This heated storm water may become runoff and drain into storm sewers, increasing water temperatures and modifying aquatic ecosystems fatally.

Evaporation

Fig.2.20: Effects UHI Phenomenon

Source: http://www.ncbi.nlm.nih.gov/ pubmed/23007798.

Fig.2.21:

Source: http://greencompanyeffect.com

Fig.2.22:

Source: http://upload.wikimedia.org

Source: http://www.aila.org.au

UHI EFFECT: “COOLING STRATEGIES”

Strategies for mitigating the UHI Effect are related to specific local factors, such as topography, climate conditions, geography, but they also depend on land-use patterns in the urban landscape. In general, the main solutions adopted to reduce the UHI Effect in high density cities concern:

- the Increase of vegetation cove r, in the form of open green areas, green roofs and green walls, which can give benefits in absorbing humidity, decreasing air temperatures through evapotranspiration, and reducing the energy used to cool buildings.

- the Increase of urban surfaces reflectivity which reduces the absorption of solar radiation - the Integration with Urban Wetlands which can give benefits in terms of cooling and regulating urban microclimates through evaporation from water surfaces and moist soil.

- the Improvement of Urban Air Flow which reduces temperatures and stops the formation

of stagnant air between buildings arrangement.

DEFINITIONS

- Green roofs are planted roofs whose vegetation keeps the temperature of surfaces cooler and provides a space for urban agriculture and outdoor community gardens.

- Vertical Greening consists of self-sufficient vertical gardens joined to the buildings envelope or interior walls. These elements can shade sides of buildings that get direct sunlight.

- Cool Surfaces , which include cool roofs and pavements, are characterized by highly reflective materials (i.e. high albedo) and light colours/white paint. These reflective surfaces can reduce heat gain, whereas materials of high thermal conductivity, such as concrete and bricks, absorb and store a great amount of solar radiation during the day and then release it in form of heat at night.

- Urban Wetlands are defined as pieces of land, permanently or seasonally saturated with water, which are characterized by hydric soil and specific vegetation, such as aquatic plants. They can exist naturally or be constructed artificially as a water management tool in urban areas.

Environmental problems in dense urban tissues 2.3

Greenery rooftop, Nanyang, Technological University.

Vertical greenery rooftop, La Caixa Forum, Madrid.

Fig.2.23: Urban Wetland, Stormwater-wetland, Perth.

UHI EFFECT IN HONG KONG

The densely populated urban area of Hong Kong provides a typical example of the UHI effect, which shows an increase of temperature from urban areas to rural surroundings between 2 and 6 Celsius degree every kilometre. In addition, there is a difference of temperature from 2 to 3.2 Celsius degree between urban green areas and the hottest urban spots. It is clear that in Hong Kong the city centre is significantly warmer than its urban margins, mainly due to the impact of the massive urbanization.

The Department of Land Surveying and GeoInformatics of The Hong Kong Polytechnic University reported that the temperatures in the inner urban areas of Hong Kong are expected to rise by two to three Celsius degree in 30 years’ time. This means that during summer days the average temperature in urban districts will increase from currently 35 Celsius degrees to 38 Celsius degrees in 2039. This latest study, carried on by Professor Janet Nichol, was based on satellite images for mapping the distribution of air temperature over Hong Kong, and estimating the impact of the urbanization over time by quantifying the plot ratio. As a result, the mean temperature is predicted to rise by 3.7 to 6.8 Celsius degree by 2100, taking into account a constant urbanization rate. This means that UHI magnitude is estimated at 0.08 Celsius degrees per decade. (University, 2012).

LACK OF URBAN VENTILATION

The Urban heat Island (UHI) phenomenon is strictly related to city ventilation, because lowlevels of airflow produce stagnant air in outdoor urban spaces, increasing temperatures and causing thermal discomfort. Air ventilation is a crucial factor to ensure good air quality in the urban fabric because it allows pollution to disperse and temperatures to fall), especially in highly dense subtropical cities. Many researchers agree that spatial distribution and

shape of the built environment enormously influence the characteristics of urban air flow, such as wind speed, pressure and patterns. Considering Hong Kong as case study, it has been demonstrated that building morphologies and narrow street arrangement significantly affect the local air ventilation, and several studies have been carried on the city’s urban tissue using computational fluid dynamics analyses (CFD). The Hong Kong Environmental Protection Department recently reported that the mean wind speeds recorded in the city over the last 10 years have decreased by 40%.

BUILDING MORPHOLOGIES

In Hong Kong’s urban area the decrease of the overall urban airflow is mainly caused by the presence of tall and overly large highrise buildings, characterized by compactness, uniform height and typical podium structures with large ground coverage. This low permeability of the urban tissue impedes proper air circulation and worsens its quality.

Although the height of buildings is a critical factor in blocking urban ventilation, many researchers reported that airflow is more sensitive to the density, and that high percentages of site coverage have more impact than buildings height on the pedestrian wind environment.

URBAN STREET CANYONS

Some experts claim that even though Hong Kong, as a coastal city, has a considerable wind potential in the urban atmosphere boundary layer, the alignment of tall and compact buildings and their aggregation in clusters create a “wall effect”, blocking the natural ventilation and worsening the outdoor thermal comfort. Taking into account the Physiologically Equivalent Temperature (PET) thermal comfort as a standard, wind speed decreasing from 1.0 to 0.3

m/s is equal to 1.9 ºC air temperature increase in the subtropical summer. An outdoor thermal comfort under typical summer conditions requires 1.6 m/s wind speed.(Chao Yuan, 2013)

Moreover, it has been shown that in Hong Kong the streets design (i.e. geometry, orientation and configuration) can reduce significantly the effectiveness of the urban air flow because of the formation of urban street canyons that trap stagnant air at pedestrian level. An urban street canyon can be considered as the space formed between two typically parallel rows of buildings separated by a narrow street. (Shishegar, 2013) The geometry of a street canyon is expressed by its “aspect ratio” which is the ratio of the Height of the building (H) to the Width of the street (W).

A canyon can be defined as:

Uniform with Aspect ratio= 1

S hallow with Aspect ratio < 0,5

Deep with Aspect ratio= 2

An additional classification depends on the ratio between Length of canyon (L= road distance between two main intersections) and Height of the building (H), subdividing the canyon in:

Short with L/H=3

Medium with L/H=5

Long with L/H =7

Environmental problems in dense urban tissues 2.3

PROPOSED VENTILATION STRATEGIES FOR HONG KONG

Currently, there are no adopted solutions for improving urban ventilation in the urban area of Hong Kong, but the government has introduced several ventilation parameters in the official urban design guidelines. Moreover, many researchers from the Chinese University of Hong Kong have carried on studies about how to enhance urban ventilation in the city, providing a series of possible solutions listed below.

1) Increasing the overall Permeability of the urban tissue, especially at ground level, is important in order to create breezeways and air paths. This could be possible by:

- linking open spaces

- creating open spaces at road junctions

- maintaining low-rise buildings along prevailing wind direction routes

- widening minor roads connected to major roads

2) Increasing Buildings Permeability , especially at pedestrian level, could be possible through a system of voids and openings in the buildings

(4) .The combination of a porosity system with appropriate wing walls helps create a difference of pressure across buildings facades, and thus it facilitates indoor airflow through openings. In the case of very deep urban street canyons or very tall buildings, a mid-level permeability is crucial to improve air ventilation performance at mid-floors.

3) Reducing the Site Coverage Ratio could help enhance the pedestrian-level natural ventilation performance. It has been demonstrated that splitting the volume of podiums into several parts helps air to circulate better at street level.

4) Creating Setbacks by stepping back buildings height in rows widens the narrow blocks

arrangement, improving air circulation at higher levels. In addition, it also contributes to increase the sky view factor.

5) Street Grid Orientation should be designed by arranging main streets along prevailing wind directions.

6) Buildings Disposition and Orientation should be parallel to the prevailing wind direction in order to avoid obstructions. Furthermore, the planning layout should provide buildings with adequate gaps and open spaces.

7) Building Height is an important factor that affects wind speed. Creating a Gradation of Height profiles toward the wind’s direction helps to improve ventilation. When it is not possible to create a height gradient, varying the buildings height helps to divert winds to the lower level.

8) Surfaces Roughness creates an aerodynamic effect at rooftop level that helps increase the overall wind speed.

9) Increasing the amount of greenery c ould help improving the effect of air stagnation.

Environmental problems in dense urban tissues 2.3

(4) Wing walls can be defined as vertical solid panels placed alongside of openings and perpendicular to the wall on the windward side of the building.

Environmental problems in dense urban tissues 2.3

Fig.2.24: Vertical cross sections showing the velocity contour and streamlines for horizontal and vertical setbacks

Source: “A modeling investigation of the impact of street and building configurations on personal air pollutant exposure in isolated deep urban canyons”, Wai-Yin Ng, Chin Kwan Chau, 2013

Source: http://www.rjl-art.com/index.php.

During the last century, high-density cities around the world have shaped a skyline based on high-rise buildings driven by one main goal: to accommodate a large amount of population. In Asia, some examples of public housing proposals reveal the lack of cultural, spatial and environmental considerations in the design proposal. These multi-storey buildings bring further effects to the urban fabric, affecting environmental conditions and disrupting any dynamic between the population and the built out of the city.

Recently more awareness regarding these conditions has influenced some architectural offices to have a different approach towards the high density skyscraper model, in which they consider the inclusion of open areas at several levels; these spaces are considered communal and semi-private for social interaction, in order to balance the lack of open areas in the urban fabric. These proposals face further challenges such as the mobility of the population to use the open spaces provided, and also a clear relation of interaction between the private and the public.

Fig.2.25: Vertical Horizon, Hong Kong

Source: http://phamngochuong.com.vn

HIGH DENSITY BUILDING BLOCKS

Highlight: high density, private space, semipublic space, greenery, flexibility, mixed use

MahaNakhon Tower by OMA, Bangkok - Thailand, 2012

Mixed-use development with apartments, retail, five-star Ian Schrager hotel and public gardens a tall tower of 77 stories that seeks to communicate intimately with Bangkok from the ground up: its series of components comprise MahaNakhon Square, a landscaped outdoor public plaza intended as a new public destination within the city; MahaNakhon Terraces, 10,000 square meters of gardens and terraces spread over multiple levels for restaurants, cafes and a 24 hour marketplace.

The Interlace by OMA and Ole Scheeren, Singapore, 2013

This complex of 31 apartment blocks, each 6 stories tall, is based on the idea of horizontally interconnected volumes, forming a less isolated residential environment. An integrated network of private and communal spaces, such as terraced gardens and courtyards, arise from the stepped morphologies on multiple levels, allowing light and air to penetrate into and through the surrounding environment.

Source: http://arch2o.com/wp-content

Sky village by MVRDV, Copenhagen – Denmark, 2008

This 116 meter tall tower is mixed use and it includes apartments, a hotel, retail, offices, and a public park and plaza. The building is composed of an aggregation of pixelated units that allows flexibility in function and integrates greenery built through a series of terraced sky gardens.

Fig.2.26: Case study 1- Proposal for a high rise mixed-use tower, MahaNakhon Tower, Bangkok, Thailand (by OMA, 2012)

Fig.2.27: Case study 2Residential Developments, The Interlace, Singapore (by OMA, 2013)

Source: http://www.mvrdv.nl

Fig.2.28: Case study 3- Proposal for a high rise mixed-use tower, Sky Village, Rødovre, Denmark (by MVRDV, 2008)

Case study 2.4

Source: http://www.mvrdv.nl

PEDESTRIAN CONNECTIVITY

Highlight: greenery, public space, elevated pedestrian connectivity

High Line Park by James Corner Field Operations, Diller Scofidio+ Renfro, New York - USA, 2006

This project is focussed on the redevelopment of a disused railroad in New York, which is constituted by a 1.45 mile-long elevated steel structure. Its transformation into a public elevated park aimed to offer an alluring break from the chaotic city

streets for users, who can enjoy the viewing area and lounge on the open lawn and seating steps. Indeed, this public space is conceived as multifunctional, offering a variety of cultural attractions and community programming as well as informal recreation, thanks to the integration with vegetation. The system of walkways, which structure this hanging urban park enhances the pedestrian connectivity across the district, offering unexpected views of the Hudson River and the surrounding cityscape.

Fig.2.29: Case study 4- Proposal for a high rise mixed-use tower, Sky Village, Rødovre, Denmark (by MVRDV, 2008)

Case study 2.4

Source: http://www.mvrdv.nl

VERTICAL GREENERY

Highlight: vertical park, permeability, public space, multi-functionality

MFO Park by Burckhardt + Partner and Raderschall, Zurich - Switzerland, 2002

The MFO Park, measuring 100 meters long, 34 meters wide and 18 meters high, is the largest pergola in the world. The design of this multilevel “park house” covers an area of 96,875 ft² and it is constituted by a double-walled construction, made of metallic trellis and open on 3 sides. The

whole structure is permeable and transparent, and it is covered with plants and traversed by walkways. Loggias and small silent gardens are located on different levels. This public space accommodates a variety of activities, such as open-air movies, concerts and theatres, or simply offers users the opportunity for gathering and informal recreation.

Fig.2.30: Case study 5- Proposal for a high rise mixed-use tower, Sky Village, Rødovre, Denmark (by MVRDV, 2008)

3. methods

3.1 Process Overview

3.2 Computational Techniques

3.3 Multi-software Data Transferring

3.4 Associative Techniques

SITE ANALYSIS

EXISTING CONDITIONS

ENVIRONMENTAL

- Low Wind Speed

- High Temperature

SOCIAL

- Land Use

- Buildings Morphologies (Height, Rooftop villages)

CRITICAL AREAS

RESEARCH CASE STUDY

AIRFLOW STRATEGIES

DESIGN LOGIC and PARAMETERS

SPATIAL QUALITY

DESIGN AMBITIONS

Blocks Aggregations scale

PRIMITIVE INPUT

Fig.3.1: Overall Diagram, Methods

This chapter illustrates the different methods that will be employed in the various phases of the process to describe the logic system on which the thesis is based. Research, analysis, design procedures and evaluation modes will be driven by principles of sustainability for a highdensity city model and digital tools and noncomputational approaches will focus especially on buildings’ morphological aspects, in terms of environmental and architectural quality at different scales. The interdependence of analytic and design methods will be used to calibrate the parameters for the several experiments and to understand success and limitations of the entire process.

The computational design of cities is a scientific and innovative way of approaching contemporary urban systems. This is coupled with transformations and growth in high density scenarios. This approach requires a simultaneous processing of large quantity of data, successively translated into precise design solutions. In each stage, the thesis adopts the combination of spatial logics, environmental responsiveness and social and cultural factors to inform a challenging urban system, with the aim to extract parameters for a design strategy that can achieve an overall urban quality.

GENETIC ALGORITHM

The development of evolutionary algorithms starts with an understanding of the two different but coupled processes that lead to the morphogenesis, variation and distribution of all living forms. Every living form is generated by two strongly joined processes, throughout differentiated time spans: the rapid process of embryological development, and the long slow process of the evolution of diverse species of forms over multiple generations” (Michael Weinstock, 2010).

Genetic Algorithms (GA) are adaptive heuristic evolutionary ideas of natural selection and genetics. The basic concept of GA is to simulate evolutionary processes that occur in nature, specifically those that follow the principles of survival of the fittest. As such they represent

an intelligent exploitation of a random search for finding solutions to an optimization problem that takes advantage of evolutionary principles; different possible solutions to the problem are iteratively subjected to “replication”, “mutation” and “selection” processes. (Wilfred Ndifon, 2011). The entire process usually starts with the initiation of a random population of candidate forms, from which those that best match the desired criteria, the “fittest” individuals, are selected. Genetic algorithms combine both growth and evolution over multiple generations. (Michael Weinstock, 2010).

The application of GA to architectural forms aims to explore innovative context-sensitive design solutions and develop a logical and thoughtprovoking way of reimagining contemporary

architecture, building a bridge between scientific and sociological paradigms. In this light, during the thesis the urban system has been developed through an evolutionary computational design process that employed Grasshopper (GH) for Rhino within Octopus’s evolutionary solver as main generative platform.This form generative method has been structured on a multi-objective optimization, which has led to a multiple set of different design solutions. With respect to single objective GA, the adopted approach allowed evaluating many morphological options simultaneously and according to a series of different fitness criteria, taking in consideration both environmental and cultural factor for the design strategy.

Fig.3.2: Genetic Algorithm Definition, GH for Rhinoceros v5

REMAPPING PARAMETERS

The parameters used in the system will be characterized by different numeric domains and thus to compare these values it will be necessary to remap them into standard domain ranges. A variety of techniques will be employed to transform this data into similar numeric values. This is an important step that allows evaluating and comparing the results of the generative process.

DIFFERENTIAL WEIGHTING

Differential weighting criteria will be used when the parameters cannot be computed together. Due to the lack of computational connection between the GA and the computational fluid dynamics (CFD) evaluation, it will be necessary to identify which parameters have higher priority. It is important to be aware that even though the two of the main goals of the thesis are improving urban airflow and minimizing disruption both ambitions could become contradictory because maximizing the built volume could result in a decrease in wind speed. Therefore, a differential weighting of fitness criteria is a key factor for the selection of specific morphologies generated in the design process. The adopted weighting technique will be based on a comparison between evolutionary computational outputs and results of the CFD analysis, in order to establish

as selective criterion, the best optimum value between maximum volume and maximum wind performance. This could provide a control over the outcomes of the entire design process.

Fig.3.4: Ranking criteria

Fig.3.3: Numeric Domain

MULTI-SOFTWARE DATA TRANSFERRING 3.3

Although the GA is able to optimize existing buildings morphologies, according to the fitness criteria of maximum volume, minimum summer solar exposure and minimum ground exposure, there is a disconnection between the generative process and other parameters. As a consequence, analyses on specific environmental conditions, such as wind performance and spatial layouts, such as pedestrian connectivity, required the use of specific simulation software, due to the inability of the GA to provide direct design solutions for these conditions. For example, the CFD evaluated the performance of the experiments for wind ventilation, while the pedestrian circulation at the ground level has been analyzed with Depth map.

SOLAR RADIATION ANALYSIS

A solar radiation analysis of the emergent open spaces has been used to verify the quality of the outdoor environmental conditions. Incident solar radiation is measured as the energy received on surfaces during a selected period of time. The calculation of this parameter is based on hourly readings during the hottest period in Hong Kong, estimated to be between June and September. According to the analyses, we evaluated the characteristics of the microclimate of the emergent open spaces and translated the values of solar radiation into temperatures. This allowed functions to be assigned to different spaces in relation to the human thermal comfort. Ladybug plug-in for GH has been used to run this analysis.

Source: https://aec-apps.com

Fig.3.6: Ladybug for GH, Solar Radiation Analysis

Fig.3.5: Multi-Software Data Transferring

GRASSHOPPER VASARI CFD

LADYBUG SPATIAL QUALITY

COMPUTATIONAL FLUID DYNAMIC ANALYIS

Computational fluid dynamics is used for solving and analyzing problems related to fluid flows. It uses numbers and algorithms to compute the results (Chao Yuan, 2011). One of the ambitions of the experiments is to maximize urban ventilation and increase airflow at the different height levels in the patch. In this light, CFD becomes an important tool for flow simulation because it allows extracting numeric and visual data about wind speed in relation to the morphology of buildings. Vasari CFD analytic software has been employed to evaluate the computational evolutionary outputs that perform better for the urban ventilation. The interdependence and exchange of information between the wind simulation and computational design tools has been crucial to the entire design process, due to the issue that the genetic algorithm does not provide Rhino and Grasshopper with a simultaneous feedback analysis for the wind optimization.

Source: http://wildeanalysis.co.uk

DEPTH MAP

UCL Depth map is an Open Source application to perform visibility analysis of architectural and urban systems. It takes input in the form of a plan of the system, and is able to construct a map of ‘visually integrated’ locations within it. (1) The Agent analysis tools in the 2D view window (Map window) are used to generate aggregate models of agents’ movement in space. These aggregate models are governed by global parameters as well as parameters defining the behaviour of individual agents. The global parameters determine the duration of analysis, when, where and how many agents are released into the system (Alasdair Turner, 2012).

This analytic tool was used to evaluate the pedestrian circulation at the ground level in the existing and optimized urban patch, to evaluate the effect of the porosity strategy and the level of fluid circulation achieved with respect to the original condition.

(1) http://www.spacesyntax.net/software/ucl-depthmap/

Source: clementcreusot.com

Fig.3.7: Example of CFD Analysis (Streamlines)

Fig.3.8: Pedestrian Analysis

ASSOCIATIVE TECHNIQUES 3.4

Evolutionary strategies have been applied to existing morphologies to explore multiple solutions for specific and context-sensitive architectural forms within their effects on the areas nearby. However, another noncomputational parameter, such as materiality related to the environmental and architectural quality of the space, can be considered as a significant factor in the computational process for creating a responsive urban tissue.

SURFACES MATERIALITY

The main driver of the experiments is to provide a comfortable outdoor environment in a highdensity city, negatively affected by the Urban Heat Island effect and low ventilation. The optimized morphologies could contribute to reduce outdoor and indoor high temperatures and absorb humidity and pollutants through the materiality of their envelope. For example, vegetation covers could lead to the reduction of excess moisture and air pollution, while material surfaces with a high albedo coefficient would be capable of reflecting the incident solar radiation. Albedo is a measure of the amount of light that is reflected from a surface without being absorbed. From the solar radiation analysis, it can be deduced which materials could be applied to the envelope of buildings in order to reduce high temperatures in the hottest months through their reflective properties.

no light reflected all light reflected

Fig.3.9: Behaviour of materials with High and Low Albedo

Fig.3.10: Materials Reflectance Spettra Source: http://www.astro.washington.edu

4. Selected patch

4.1 Site Analysis

4.2 Rooftop villages

4.3 Analysis of Existing Urban ventilation

4.4 C onclusion

Source: http://photo.sf.co.ua/id75?lang=ru

Fig 4.1: Shamp Shui Po district

Site Analysis 4.1

The experiments will be carried out in an area of 1.7 kilometres between two of the most vulnerable districts of Hong Kong: Sham Shui Po and Yau Tsim Mong. The first is characterised by an industrial and commercial background and the other is considered a shopping and business centre. With a population of 203,094 inhabitants and a density of 117,395 inhabitants per square kilometre, the area has one of the highest peaks of density and urban heat island effect intensity.

The urbanisation of the Kowloon Peninsula is clearly evident in the physical fabric of Sham Shui Po. During the 1980s, large tracts of land were reclaimed for the construction of highways, railways and housing developments. The centre of Sham Shui Po shifted inland, defining differences between the old Hong Kong and the new enterprising waterfront characterised by new large-scale developments.

The path landscape is one of the most controversial aspects of the city: a height gradient throughout the patch, where the east coast is filled by important high-rise financial and housing towers as part of the infrastructural

renewal of the Kowloon Peninsula. On the west coast, the area is filled by old shop houses that vary between seven and 10 storeys high; these buildings host a mix of purposes and include offices, shopping centres, street markets, a secondary pedestrian network, housing, and rooftop villages, creating vibrant patterns of interaction between the two districts. (Fig.4.2)

Source:

Building and Environment,Chao Yuan, Edward Ng, 2011

Fig.4.3: High-rise buildingsShophouses, Sham Shui Po district, Hong Kong

FAR: 7.3

n. DU: 768

Site Analysis

Cruciform Tower Population 3.072

Area 27.741 m2

Floors 32

The area is affected by several environmental conditions such as a lack of urban ventilation and being an urban micro-climate. In the redundant towers on the coastal block, the patch’s urban ventilation has seen wind speed drop over the last decade. Measures of the urban scale have shown high concentrations of NO2 and rising temperatures at the ground level. Inner conditions in the buildings are not recorded, but overcrowding suggests that indoor temperatures are 2ºC more than the urban area.

FAR: 6.82

n. DU: 234

Tower Podium

Population 2.106

Area 11.200 m 2

Floors 21

FAR: 11,7

n. DU: 504

Tower Population 1.512

Area 7.284 m 2

Floors 42

FAR: 3,5

n. DU: 448

Sham Shui Po is one of the poorest districts of the city, portrayed as a decaying neighbourhood of claustrophobic apartments, where the shortage of public space is exposed on the bustling overcrowded streets. The area is a lively commercial centre where various scales of marketing take place; wholesale, retail and informal markets are steps away from each other. Apparent economic prosperity with new capital investment in shopping centres exists alongside the miserable living conditions of the residents.

(Fig. 4.3)

Block Population 1792

Area 9.492 m 2

Floors 14

Fig.4.4: Buildings morphologies, Sham Shui Po and Yau Tsim Mong districts, Hong Kong

Source:

LCE Cities, Urban Age Cities Compared, 2011

Site Analysis 4.1

scheme was executed by private developers, mainly contractors, using land reclamation and building projects (Smith, 1995). Two streets, Nathan Road and Boundary Street, played a critical role for the layout of Sham Shui Po. Nathan Road was the

Continuity and change in the

rst major road built in Kowloon, while Boundary Street was merely a line of high bamboo fences. The regulating line for the orthogonal layout of Sham Shui Po was set by bisecting the angle formed between Nathan Road and Boundary Street (Figure 2).



Figure 2. The growth of Sham Shui Po.

Fig.4.5: Growth of Sham Shui Po (1902 - 2005)

Source:

urban transformation of old districts, Puileng Woo, Ka Man Hui, 2010

Fig.4.6: Existing Patch, Land use

Site Analysis 4.1

Fig.4.7: Existing Patch, Rooftop villages

A high percentage of the patch’s population consists of marginalised groups with low economic status from Mainland China and Southeast Asia; some of them are part of the public housing programme that comprehends 40 per cent of the total housing of the area. The principal aim of public housing was for all of the levels of the buildings to be designed strictly for residential usage; however, from the outset they have been altered at ground- and top-floor levels to supply the need for other activities. The existing morphologies are the product of manmade alterations in which small markets— narrow passages, informal settlements and social activities—take place.

Site Analysis 4.1

The interventions to the existing buildings are the consequence of a set of allowances from the early years of the Hong Kong Government. As the population grew during the 1960s, investment in infrastructure was largely concentrated on the creation of adequate housing stock, but there was a deficiency in services such as schools and churches; as a result, the Government allowed the establishment of informal structures on top of buildings that could host educational and physical activities. With the shortage and high cost of land, other usages started to emerge. These are the roots of a major social problem: rooftop villages. (Fig.4.6)

Source:

"Portraits from Above: Hong Kong’s Informal Rooftop Communities", Stefan Canham,Rufina Wu ,2009

Fig.4.8: Three districts Data comparison

Rooftop villages 4.2

Fig.4.9: Rooftop Villlages general aspects, Frontal Section.

Source:

"Portraits from Above: Hong Kong’s Informal Rooftop Communities", Stefan Canham,Rufina Wu ,2009

WHAT

-“poor housing”

- illegal but “tolerated” by the government

- temporary and informal rooftop structures

- concrete, bricks, wood, metal sheets, flimsy material

- dwellings’ area= from 9 to 28 sq. m.

WHERE

- Sham Shui Po, Kwun Tong, Tai Kok Tsui districts

- old urban areas of the districts

- old (30-40 years) dilapidated tenement buildings

- migrants from Mainland China and Southeast Asia

- marginalized groups with low economic status

WHY

- shortage of land in Hong Kong for hilly topography - extremely high housing prices

Rooftop villages 4.2

Source: http://pantip.com

Rooftop structures are temporary structures built without the formal approval of the government. People who either intend to live in them, or sell or rent them for profit, build them. They are supposedly “illegal” and disapproved of by the authorities, but they are also “tolerated” and “recognized” by the government. (Wu, Portraits from above - Hong Kong's Informal Rooftop Communities, 2009)

The area has 48 per cent of the existing rooftop villages. They have served the critical function of providing accommodation for low-income,

marginalised communities. According to the most recent census of 2006, there were 1,554 households, accommodating 3,962 rooftop dwellers. Health and safety conditions inside the informal settlements are very poor; the phenomenon of cage houses is also part of the problem, where living areas are reduced to 1m² per person.

The Government has unofficial yet specific regulations towards rooftop villages in terms of relocating the inhabitants or demolishing the structures; nevertheless, some of the

dwellers have been offered relocation in nearby cities through the public housing programme. Ironically, the offers have been rejected due to the desire for proximity to the urban fabric that Hong Kong offers.

Fig.4.10: Rooftop Villlages, Sham Shui Po district, Hong Kong

Agricultural Products Urba Agricultural Network Informal Rooftopgarderns

Situation New Phenomenon Vertical Eco-system: 97.7% imported

promote micro-economies rediscover local identiy use of public space

Source: http://green-living-hk. blogspot.co.uk

Fig.4.11: Urban agriculture, Sky farms in Hong Kong

Analysis of Existing Urban ventilation 4.3

The high rate of urbanisation and compact footprint in Hong Kong has had a significant impact on ground-level ventilation. One of the main challenges of the experiments carried out during the thesis has been how to optimise the urban porousness at ground level to ensure adequate natural ventilation in the urban area. High-rise building blocks and deep-street canyons are one of the main urban characteristics of the patch. In one of the studied districts, Yau Tsim Mong, air flow was measured and compared with previous site analysis in order to understand the effect of air flow on temperature; it was observed that in the last decade the mean

wind speed at 20 metres above the ground level has decreased by about 40 per cent, from 2.5m/s to 1.5m/s (Chao Yuan, 2011). In summer, a decrease in wind speed from 1.0m/s to 0.3m/s is equal to a 1.9ºC temperature increase, meaning that in our patch, temperatures have risen by 2.7ºC. The increase of temperatures in the patch suggests that in order to achieve an outdoor thermal comfort under typical summer temperatures, we will require between 1.6m/s and 2.28m/s to decrease temperatures and provide more pleasant open-air conditions.

Fig.4.12: Patch, Analysis Urban Ventilation. Several levels.

The existing patch presents several architectural and environmental conditions that define the area’s potentialities and deficiencies. The patch tells the history of the city and how several interventions have affected the build environment. It is important to understand the existing urban structure and how it has played a key role in the historic transformation of the patch; the structure of the old neighbourhood’s fabric exposes its cultural identity and the importance of its activities for economic growth, while the renewal waterfront displays a preeminent hub for global trade.

A clear understanding of the site analysis will allow us to define the effect of the specific patch morphologies and how they have affected the existing urban conditions. The analysis can then guide us to address the possible solutions to improve environmental conditions and how this could be achieved through strategies applied to the existing buildings. The exploration of parameters that can change the buildings’ morphologies—such as setting back buildings, separating long buildings, stepping the podium, and opening the permeability of towers and podiums—will define how the strategies can be applied to the improvement of the air flow of the urban fabric.

The analysis of the patch suggests an intervention based on minimising the disruption in order to avoid the displacement of communities and to keep the patch’s cultural identity. A key factor of social inclusion will shape the emergent public space and will define the dynamics of interaction between the markets and other activities at podium levels.

5. design development

5.1 Overview

5.2 Environmental Factors

5.3 Social & Architectural Aspects

5.4 C onnectivity

The urban design proposal for the redevelopment of a high-density district of Hong Kong considers the extreme local climate conditions and the insufficient provision of public services and open spaces as an indication to employ as a main driver the creation of a balanced distribution of social provisions and green areas within a comfortable microclimate in the residential urban tissue. The secondary ambition is to facilitate pedestrian movement throughout the site at multiple horizontal and vertical levels. The overall design target is to address the transformation of the high-density urban fabric towards a responsive urban system, able to accommodate densification without neglecting its spatial and environmental quality.

Source: http://reinnervate.com

environmental factors 5.2

Source: http://www.designboom.com

Pore (from Greek poros) means “a minute opening”. Porosity or “the state of being porous” in the context of organic chemistry and the study of plants and animals indicates the existence of small openings. In biology and in medicine porosity is defined as: “the attribute of an organic body to have a large number of small openings and passages that allow matter to pass through”. The forms, sizes and distribution of pores are arbitrary. (Kotsopoulos, 2007)

The concept of porosity, imported from biology and organic chemistry, has been already applied to the urban and architectural context to achieve openness, permeability and transparency of forms. For example, porosity was re-interpreted from Steve Holl’s studio in several architectural

projects, in order to be used in a new tectonic/ urban context, to guide the production of a sponge-like building morphology. (Kotsopoulos, 2007)

A series of design operations can transform building morphology into a “porous machine”, able to alter the temperatures, light quality, humidity within a building. Porosity can define many features of an architectural space, marking physical boundaries between no-built up and formal built spaces.

In our thesis, the ambition to adopt a design strategy capable of combining environmental and architectural qualities using the idea of porosity was particularly interesting. We

employed this concept as the main design tool for the optimization of existing morphologies for the urban airflow and with positive outcomes at the architectural scale as well. Porosity was conceived as a system integrated mainly with the structural but also with the skin and window layouts of existing buildings. It required subtraction of smaller masses from a larger volume to achieve “breathable architectures”. Indeed, the design process, based on both computational rules and conceptual frameworks, intended to transform the existing morphologies by means of a system of vertical cavities to ensure the penetration of light and the circulation of air.

Fig.5.1(a,b): High and low Porosity polystyrene designed for 3D cell culture

Fig.5.2: Urban Porosity, Ansan, South Korea (by BIG Architects, 2008)

Fig.5.3: Diagram, Porosity geometrical operations for Simmons Hall, Cambridge, MA, USA (by Steven Holl, 2002)

Source:

Design concepts in architecture: the porosity paradigm, Sotirios D. Kotsopoulos, CEUR Workshop Proceedings, 2007.

Fig.5.4: Porosity Block, Simmons Hall, Cambridge, MA, USA, (by Steven Holl,2002)

Source: http://en.wikipedia.org

Source: http://terraurban.wordpress.com

The purpose is to propose a high-density and interconnected locality in Hong Kong, which embraces existing conditions and social values as essential design inputs, for stimulating economic, cultural and social growth. The choice of this area, located in the north-western part of the Kowloon Peninsula, was made with the intent to operate in a critical scenario, characterized by striking social contradictions and serious environmental problems. Indeed, the district has developed with no control over time and currently is mainly defined by lack of open spaces, and a hyper-dense, poor quality housing that accommodates low-income people. The phenomenon of the rooftop villages, as discussed earlier, is widely spread throughout the patch, and the project aims to recover these poorest sectors through an approach of urban inclusion instead of disruption. We believe that improving the general quality of the urban environment could bring about positive effects on marginalized areas by establishing

a sense of acceptance, integration and dignity among people. The metamorphosis of Medellin, in Colombia, is a significant example of how architecture and design can empower the poor communities, previously approached by lower quality interventions.

The urban proposal provides diversification of functions inside building typologies and the permeability of the building morphologies at ground and top floor levels creates an easy access to emergent public open spaces by means of facilitating fluid pedestrian circulation. The Growth strategy generates additive volume, distributed within the different building typologies and housing new mixed-use programmes avoids extreme zoning and segregation of land-uses. Furthermore, it also allows the recovery of part of the lost demographic density, which occurs from the subtraction of urban volume for the creation of open spaces within the buildings. The formation of a collection of open spaces,

public, semi-public and semi-private, aims to preserve the local identity of the district, promote the small local business linked to the Chinese tradition of open street markets, and also shape a cultural and social environment for different types and ages of users. In fact, the wide range of sizes of open spaces, from small to large, could embrace the two main opposing social behaviours demonstrated by Chinese people; a reserved attitude, linked to a traditional sense of privacy, and a contemporary need for public display, due to the transformation to a globalized society. In this light, a distributed network of pocket open spaces could satisfy the need to live more parochially, whereas larger and multipurpose areas could accommodate a variety of activities that require a greater number of users.

Fig.5.5: Library-Parks, Medellin,Columbia (by G. Mazzanti, 2007)

DEFINE OPEN SPACE MULTILAYER OF CONNECTIVITY

As a result of the porosity strategy a series of emergent open spaces are distributed throughout the patch. The emergence of clusters that connect larger areas of public space aims to integrate the public spaces to the existing layers of connectivity in the city. The clusters are connected under two criteria: large areas of open public space and closeness to urban attractors.

We identified blocks with a larger surface area of open space in order to evaluate how close they were to urban attractors, such as:

- Public Transportation system (MTR): to provide a direct accessibility from other districts of the city

- Existing secondary pedestrian layer: to extend the existing pedestrian network and connect it to the emergent open spaces

CREATE CLUSTERS

DEFINE

Type of Connection

- Rooftop Villages: to generate social inclusion by generating new dynamics of interaction between poor housing and its surroundings

-Services and social provisions : to strengthen the linkage with areas where there are public services

- Existing Green Areas: to create an extended and integrated network of public spaces

Three areas are identified in the patch for the development of clusters, and are located between three and five minute walk from the two main public transportation nodes of the patch: Sham Shui Po and Olympic Tube Station.

Each cluster will have several levels of connectivity according to the floating population A hierarchy of flows will define the amount of connected blocks and the mutual relation at building, block and cluster scale. High Flow will

be designed for an estimated index of 800 to 1200 pp./h, Active Flow for 400 to 800 pp./h, and finally Low Flow for 400 pp./h.

Fig.5.6Diagram, Connectivity’s Strategy

6. experiments

6.1 Strategy’s Parameters

6.2 Patch scale: Experiment 1 and 2

6.3 Patch scale: Experiments comparison

6.4 Limitations

6.5 Porosity and Pedestrian Circulation

URBAN BUILDING TYPOLOGIES

Previous studies on the current situation on the selected patch (Chapter 4) showed that the area has a high population density, characterised by high-rise buildings with a business and residential function on the southern coast boundary, and by medium- and low-rise buildings, mainly residential, in the northern part. In particular, as previously discussed, the phenomenon of illegal informal settlements on the rooftop surfaces of existing buildings, known as ‘rooftop villages or sky slums’, is widely diffused in this northern area of the patch.

Following this analysis, the overall strategy was based on the combination of environmental performance, in terms of maximised urban wind ventilation and minimised solar exposure in the

hottest month, and architectural ambitions, in terms of high-density building morphologies, integrated with open spaces and socialprovisions.

Existing buildings were considered as geometrical primitive input for optimisation of the patch, and they were classified according to their typology, height and destination. Four ranges of height were established:

-Low rise Building Blocks with an Height= 3-30 m (1-10 floors)

-Medium rise Building Blocks with an Height= 33-60 m (11-20 floors)

-High rise Building Blocks with an Height= 63-90 m (21-30 floors)

-High rise Towers with an Height> 90 m (>30 floors)

Rooftop villages and existing social provisions were directly excluded from the strategy to avoid negatively affecting the density in critical nodes, and so as not to reduce the current amount of facilities and services for inhabitants through disruptive intervention. Nevertheless, the general strategy aimed to indirectly regenerate them, thanks to the environmental and social benefits that they can deduce from the improvement of their surroundings.

Fig.6.1: Selected Patch, Classification of Existing Buildings by height

n. floors > 30

H > 90 m

n. floors = 21-30

H = 63-90 m

n. floors = 11-20

H = 33-60 m

n. floors = 1-10

H = 3-30 m

WIND STRATEGIES EXPLORATION

An exploration of different wind strategies was conducted in order to understand how to improve air flow at the several height levels in the urban patch, and also how to acquire knowledge about possible parameters, such as porosity and roughness of the surfaces, to apply to existing building morphologies. The effect of porosity on the urban ventilation was tested at different height levels, and additional parameters for redirecting air flow to specific points were studied. The test was run on four existing blocks, considering a porosity parallel to the prevailing east wind and a variation of the wind vector of ±30 degrees. The aim was to understand how to maximise air flow by using breezeways and pedestrian permeability all over the district.

STRATEGY 1

Porosity at ground level is applied, considering a set of vectors breaking the podium along the prevailing wind direction and within a range of a 30 degree angle. In case 1, the dimension of voids has an inlet equal to the outlet (6 metres), while in case 2 inlet and outlet are 6 and 9 metres respectively. In both cases, the amount of porosity is set to a value between 30 and 50 per cent. It is clear from the CFD analysis that the increased wind permeability in the podium layer is very useful for leading air flow to deep street canyons.

STRATEGY 2

It has been observed that there is more ventilation on the top-floor levels of the patch; consequently, it can be deduced that porosity applied to top floors could be used to bring benefits to lower levels. Thus, in cases 1 and 2, porosity is applied to the buildings at topfloor levels from 9 to 70 metres. The permeability can vary between 10 and 15 per cent in both cases. In addition, although in case 1 there is no inclination applied along the y axis, in case 2 an inclination between 0 and 15 degree angles is considered in order to redirect the air flow from the top-floor level to the ground-floor level. As shown, permeability at the top-floor levels could redirect wind from above to the pedestrian level.

Fig.6.2: Wind Strategies Exploration- Selected four blocks

STRATEGY 3

Variations on the width of the urban canyons and buildings’ setbacks allow air flow to be driven from the urban canopy layer to the ground level. Therefore, different types of setbacks are applied to the existing buildings in order to increase the width of the existing streets. In case 1, an inclined setback is set in relation to the street width (y = x1), while in case 2 we can find a stepped setback with a depth of 3 metres on the middle levels (y = 3 metres), and a depth of 6 metres on the top-floor levels (y = 6 metres). Both cases have a range of permeability arranged from 10 to 15 per cent.

STRATEGY 4

Roughness on the rooftop surfaces can create a variation of heights in the urban canopy layer in order to break the continuous height of buildings, which blocks wind at higher levels, and can also be used to direct air flow towards the patch. This strategy is applied to lower buildings with a height between 21 and 30 floors. Their rooftop surfaces are split into a grid and each cell is extruded vertically from 3 to 6 metres. The percentage of porosity is set between 10 and 15 per cent.

STRATEGY CONCLUSION

From the CFD analysis of the different strategies, it is observed that any porosity could improve urban ventilation, but only the redirection of air flow from the upper floors could have a significant effect on the pedestrian level. Due to the vertical profile of the mean wind velocity,

that decreases air flow performance at the lower levels, permeability at the podium level does not appear to improve the urban ventilation, even with 50 per cent of porosity.

Furthermore, the air flow above the urban canopy layer may not easily enter into the deep street canyons to benefit the wind environment at the pedestrian level. Thus, the wind velocity ratio at the ground floor is mostly dependent on the wind permeability of the upper levels and podium layer. The roughness did not increase urban ventilation, but it was effective at redirecting the air flow of the urban canopy layer. To conclude, some of these strategies can guide the settings of the parameters applied to the algorithm: porosity at ground and top-floor levels, and roughness strategy on the rooftop surfaces.

Fig.6.3: Wind Strategies Exploration- Four Strategies

5 0 m/s 5 m/s 0 m/s Wind Direction EAST

AA | EmTech | 2013-14 | Dissertation

Adaptable Morphogenesis

1.Porosity Ground 30% Inlet 6m Outlet 6m

6. Porosity at Top Floors 10% Inlet 6m Outlet 6m Angle 10

2. Porosity Ground 30%Inlet 6m Outlet 18m

7. Porosity at Top Floors 10% Inlet 6m Outlet 6m Angle 10, connections

3. Porosity Ground 50%Inlet 6m Outlet 6m

8. Stepped Set Backs

4. Porosity Ground 50%Inlet 6m Outlet 18m

9. Inclined Street Canyons

5. Porosity at Top Floors 10% Inlet 6m Outlet 6m

m/s

m/s

URBAN VENTILATION - LEVEL 0

strategy’s parameters 6.1

10%

AA | EmTech | 2013-14 | Dissertation

URBAN VENTILATION - AVERAGE HEIGHT 20M

Adaptable Morphogenesis

1.Porosity Ground 30% Inlet 6m Outlet 6m

6. Porosity at Top Floors

Inlet 6m Outlet 6m Angle 10

2. Porosity Ground 30%Inlet 6m Outlet 18m

7. Porosity at Top Floors 10% Inlet 6m Outlet 6m Angle 10, connections

3. Porosity Ground 50%Inlet 6m Outlet 6m

8. Stepped Set Backs

4. Porosity Ground 50%Inlet 6m Outlet 18m

9. Inclined Street Canyons

5. Porosity at Top Floors 10% Inlet 6m Outlet 6m

10.Rugosity

Fig.6.5: Wind Strategies Exploration- CFD Analysis 20 m Height

AA | EmTech | 2013-14 | Dissertation

URBAN VENTILATION - 40M

Adaptable Morphogenesis

1.Porosity Ground 30% Inlet 6m Outlet 6m

6. Porosity at Top Floors 10% Inlet 6m Outlet 6m Angle 10

2. Porosity Ground 30%Inlet 6m Outlet 18m

7. Porosity at Top Floors 10% Inlet 6m Outlet 6m Angle 10, connections

3. Porosity Ground 50%Inlet 6m Outlet 6m

8. Stepped Set Backs

4. Porosity Ground 50%Inlet 6m Outlet 18m

9. Inclined Street Canyons

5. Porosity at Top Floors 10% Inlet 6m Outlet 6m

10.Rugosity

m/s

Fig.6.6: Wind Strategies Exploration- CFD Analysis 40 m Height

POROSITY AND GROWTH STRATEGIES

As result of the exploration of urban ventilation strategies, porosity and roughness strategies were chosen as drivers to enhance air flow in the patch. First of all, the creation of a subtractive porous system applied to the existing buildings, transformed them into wind permeable organisms, and provided them with open spaces on multiple levels, as a result of the subtracted volume. Second of all, not only did the application of an additive growth strategy on existing buildings rooftop levels aim to increase wind velocity through surfaces roughness, but this mass addition brought about the emergence of new and various functions.

Two experiments were run at the patch scale by using evolutionary computational tools. The analysis of the main environmental problems and social conditions in the patch identified critical areas of intervention. As a consequence,

a porosity gradient was applied to the whole patch in order to diversify the permeability of the urban tissue at specific points. High porosity was applied to the patch’s boundaries because of the presence of high-rise buildings, blocking the wind on the southern coastal side, and the lack of open spaces on the northern side. However, medium and low porosity were defined in zones with high residential population density in order to minimise the amount of built volume to remove.

In both experiments, the porosity gradient was applied at different levels of height, such as ground-floor, podium and top-floor levels, for each building type. It is clear from the table above that the percentage of high porosity was slightly increased in Experiment 2 with respect to Experiment 1, whereas the proportion of medium and low porosity stayed equal.

Finally, the growth strategy was applied to specific building types characterised by moderate ranges of height, such as 3–30 metres and 33–60 metres. No volume was added to taller buildings in order to avoid an increase of height worsening the general urban ventilation performance. In the selected buildings, the height of the additive volume was increased by one floor unit in comparison to Experiment 1.

Fig.6.7: Strategy - Subtraction and Addition of Volume

strategy’s parameters 6.1

Fig.6.8: Map of the Porosity Gradient applied to the existing patch

Tab.6.1: Experiment 1 and 2Porosity Gradient’s percentage by area and height level

strategy’s parameters 6.1

Fig.6.9: Porosity Gradient’sexperiment 1

GENERAL COMPUTATIONAL SETUP

In each experiment, a multi-objective evolutionary algorithm was applied to existing morphologies, considered as primitive geometries. The body of each building is structured on a regular grid of cells and the size of cells varies according to three levels of height, defined as groundfloor level (± 0.00 m), top-floor level (+9.00 m) and rooftop level (+ Hmax building). The grid subdivisions are bigger at the ground-floor level and rooftop level in order to maximise the air flow and increase the surface areas of open spaces and emergent functions. On the contrary, the top-floor level is characterised by smaller cells, which tend to be more adequate for residential units, as well as communal and semi-private open spaces.

Therefore, in both experiments the body plan for each building typology consists of specific number of cells per each of the three height levels. Moreover, as shown in the table above, in Experiment 1 the building morphologies

were first modified on a smaller gridded plan, whereas in Experiment 2 the number of cells’ subdivisions was generally decreased over the entire patch—particularly in specific points, where buildings aggregate in clusters nearby public transportation nodes. The phenotype is determined by two variables (genes) applied to each of the cells of the body plan. The differential intensity of the modifying genes’ effect on the body plan is regulated by homeobox genes. The variables for each cell are:

(a) Height of vertical extrusion in multiples of 3 metres (equal to the standard height of one storey).

(b) Location of cells, vertically extruded up to the Hmax of existing buildings.

The vertical extrusion in multiples of 3 metres can only be modified within a certain range, which is dissimilar for each building typology

and depends on the height of a specific building. For instance, the extrusion of cells is between 0 and 9 metres at ground floor level, between 9 metres and Hmax of the building at top-floor level, and finally between 3 and 12 metres at rooftop level.

The percentage of the cells totally extruded up to the maximum height of the building is fixed. Indeed, this factor contributes to regulation of the percentage of porosity in the urban tissue. On the other hand, the location of all cells varies randomly.

Finally, the fitness criteria influencing the generation of phenotypes are maximisation of building volume, minimization of building envelope’s solar exposure in July (hottest month), and maximisation of the shadow on the ground.

Tab.6.2: Experiment 1 and 2- Grid Subdivision by level

6.2

patch scale: experiment 1 and 2

Fig.6.10: Experiment 1 and 2Porosity Strategy

patch scale: experiment 1 and 2

Fig.6.11: Experiment 1 and 2Growth Strategy

6.2

patch scale: experiment 1 and 2

Fig.6.12: Experiment 1 and 2Fitness Criteria

patch scale: experiment 1 and 2

1) ENVIRONMENTAL

- Enhance Urban Ventilation

GENERAL COMPUTATIONAL FLUID DYNAMIC SETUP

Computational fluid dynamic will be used throughout the experiments in order to analyse the impact of the different morphologies on urban ventilation. In this study, we will take into account the characteristics of the dense urban morphologies and the site’s prevailing winds. The urban fabric will be tested at different scales, such as patch, cluster and block scale, in order to achieve more accurate results.

For the analysis, it is relevant to consider that the air moving on the Earth’s surface is slowed down by frictional forces. These forces have a decreasing effect on air flow as the height above the ground increases, resulting in mean wind speed increasing with height, up to a point where the effects of surface drag become insignificant. Therefore, the entire patch and some specific sub-areas will be analysed using a three-dimensional (3D) Computational Fluid

Dynamic analysis at podium level where drag is more significant (3–9 metres), at a height of 30 metres, at the urban canopy layer (50 metres), and finally at the top of high-rise buildings (100–150 metres). Specific criteria will be used to analyse and compare different results.

DATA

WIND INPUT

-Direction: East

-Speed: 3 m/s

- Grid Resolution: Patch

Rougosity on rooftop surfaces

Increase

patch scale: experiment 1 and 2 6.2

EXPERIMENT 1

SETTINGS

For the entire patch in Experiment 1, ten generations of ten individuals each were run in Grasshopper using the evolutionary solver Octopus. The evolutionary parameters, such as Mutation Probability, Mutation Rate, Elitism and Crossover, were changed every three generations.

RANKING

Three individuals with the highest value of volume were selected over ten generations; they were later tested for wind performance. It was clear from the Fluid Dynamic analysis that all three selected individuals performed similarly with regard to urban ventilation. As a consequence, the patch with the highest value of volume was chosen as final among others.

RESULTS: VOLUME AND OPEN SPACE

Experiment 1 shows that the initial volume removed was around 32 per cent of the original total volume. The volume added through the growth strategy is 1.117.395m³, which is about 20 per cent of the initial volume subtracted. As a result, approximately 26 per cent of the total original volume was lost, exceeding the initial target by 6 per cent.

In addition, as a result of the porosity strategy, a series of open spaces were created by the subtraction of volume. The dense pixilation of the morphologies brought about the creation of open spaces characterised by small surface areas and with an influence at the local scale of the building. The data show that the ratio of public open space per inhabitant has been increased by 47 per cent with respect to the existing value.

Tab.6.3: Experiment 1Genetic Algorithm Parameters

patch scale: experiment 1 and 2

Primitive Input Experiment 1

Ops Atot ex= 236.844 m²

Vtot ex= 17.234.980 m³

- Double Existing Public space (Ratio ex = 1.66 m²/inhab.)

GOALS

- Reallocate min 40% of V removed

- V disruption <= 20% of Vtot ex

Ops Atot Exp1= 399.050 m² Vtot Exp1= 12.849.396 m³

Ratio 1-Ops = 3.15 m²/inhab.

V1 growth= 1.117.395 m³ (= 20.30% of V2 removed )

V1 disruption= 4.385.584 m³ (= 25.5% of Vtot ex)

V1 removed= 5.502.979 m³

RESULTS

Fig.6.13: Existing patch and Experiment 1- Results comparison

RESULTS: URBAN VENTILATION

A CFD analysis was carried out to identify whether the parameters set up in the algorithm have improved the existing urban ventilation. The patch has been analysed at ground floor level, as well as 50, 100 and 150 metres, without considering the context. It is pertinent to highlight that the resolution of the CFD analysis at patch scale is not accurate, and thus it can be observed that the wind performance of the modified morphologies has changed slightly. However, this analysis can provide an overall understanding about how the morphologies could alter air flow in different areas of the patch.

As is evident from the wind analysis of the existing patch, the ground level lacks complete air flow (0m/s) and Experiment 1 shows no improvement with regard to wind ventilation at a pedestrian level, regarding the 50 per cent of

porosity applied. These 3D CFD simulations analysed different horizontal sections of the patch, up to the total height of the buildings, in order to understand the impact of the urban ventilation from the bottom upwards.

It can be seen that, in this case, the vertical profile of buildings significantly reduces air flow performance at lower levels. At 50 metres, at point A, the roughness strategy was applied in order to relocate the volume removed by the porosity strategy. Here, it is observed that there is a decrease in the amount of air flow, due to the increase of the building’s height. On the contrary, at point B, it is obvious that wind speed increased from 0m/s to 2m/s in some areas, thanks to the high porosity applied to the existing buildings. This increase of wind velocity positively affected the west urban ventilation of

the patch.

As a result of the roughness strategy, we can see a decrease of air flow at point C, at 100 metres, and consequently its effect on the low and medium porosity area. At point D, it is observed that no air flow has been improved; therefore, wind speed has been reduced from 3m/s to 0m/s.

At 150 metres, air flow has been increased at point E where a high level of porosity was applied to the high-rise buildings to reduce their wall effect. This improvement can only be seen at this top level. By comparing these results with those of the existing patch, it emerges that the wind performance varies according to the different modifications of the building morphologies, bringing about improvements in some specific areas. Indeed, in Experiment 1 it is still evident that the towers located on the southern side of the patch do not allow the ventilation to pass through the patch, and for this reason these morphologies need to be reconsidered in the next stage.

Furthermore, a wind analysis was carried out at a detailed scale in order to obtain a visual higher resolution of the results, and to get a

patch scale: experiment 1 and 2 6.2

clear understanding of how the urban ventilation is affected by existing and modifiedmorphologies. Six blocks, composed of low-rise buildings and located in Sham Shui Po district, were compared at different levels: ground, 10 metres, 30 metres and 50 metres.

Overall, wind ventilation has been improved at several levels; for example, at 30 metres porosity, no positive effect on air flow was observed, whereas other adjacent areas accounted a wind speed of between 3m/s and 4m/s. By identifying these differences of wind speed, it could be possible to define different functions in the emergent spaces, based on outdoor thermal comfort.

Comparison of CDF analyses between Existing

patch scale: experiment 1 and 2 6.2

Fig.6.15: Existing Patch

patch scale: experiment 1 and 2 6.2

Fig.6.16: Patch - Experiment 1 Output

EXPERIMENT 2 SETTINGS

In Experiment 2, for the entire patch, 20 generations of 10 individuals each were run in Grasshopper using Octopus’s evolutionary engine. The evolutionary parameters, such as Mutation Probability, Mutation Rate, Elitism and Crossover, were changed every seven generations.

RANKING

Three evaluation criteria—minimum solar exposure in July, maximum value, and minimum volume—were used to rank all individuals and choose the three fittest individuals for each of the three parameters. The urban ventilation performance of the three selected patches was tested by using Vasari, a Computational Fluid Dynamic analytic tool. The wind analysis showed that the fittest individual for minimum solar exposure is the most optimised for the wind. Thus, this individual was chosen and reputed the best option, both for the air flow maximisation and its intermediate value of volume between the two extremes.

Tab.6.4: Experiment 2Genetic Algorithm Parameters

patch scale: experiment 1 and 2 6.2

EXPERIMENT 2- EVALUATION SELECTED PATCHES

Adaptable

Fig.6.17: Experiment 2CDF analysis of the three selected individuals

EXISTING PATCH

Primitive Input

Ops Atot ex= 236.844 m²

Vtot ex= 17.234.980 m³

- Double Existing Public space (Ratio ex = 1.66 m²/inhab.)

GOALS

- Reallocate min 40% of V removed

- V disruption <= 20% of Vtot ex

Experiment 2

Ops Atot Exp2= 393.810 m²

Vtot Exp2= 13.627.673 m³

Ratio 2-Ops = 3.10 m²/inhab.

V2 growth= 1.823.430 m³ (= 33.6 % of V2 removed )

V2 disruption= 3.607.308 m³ (= 21% of Vtot ex)

V2 removed= 5.430.738 m³

EVOLUTIONARY OUTPUT

RESULTS: VOLUME AND OPEN SPACE

The quantitative results show that in Experiment 2 the initial volume removed was roughly 5.4 million cubic metres, about 30 per cent of the existing total volume. It was possible to regain one third of the initial volume removed through the growth strategy. This allowed us to maintain our aim of only losing around 20 per cent of the original total volume.

Furthermore, decreasing the grid subdivisions in Experiment 2 led to obtaining a series of open spaces with a variety of dimensions. Larger gridded plans were specially applied to morphologies aggregated in clusters in order to achieve open public spaces with larger surface areas in specific points of interest. As can be seen from the data, the porosity strategy made

RESULTS

Tab.6.5: Existing patch and Experiment 2- Results comparison

RESULTS: URBAN VENTILATION

A CFD analysis was carried out to evaluate the performance of the revised computational parameters in Experiment 2. Roughness was incremented by 3 metres for each typology, while porosity was increased by 10 per cent in the high porosity area, bringing about a general improvement in urban ventilation. The patch was analysed at the ground floor, 50 metres, 100 metres and 150 metres. CFD analysis at the patch scale allowed us to observe moderate changes, as a consequence of the strategy’s application.

Similar to Experiment 1, Experiment 2 sees no improvement in the urban ventilation at the ground floor with respect to the existing situation. One of the main reasons for this result remains the Earth’s friction that reduces the input wind speed at ground level.

patch scale: experiment 1 and 2 6.2

At 50 metres, an overall decrease of air flow onthe boundaries of the patch is shown, while the roughness strategy increases the building‘s height in order to direct air flow. In this CFD resolution, the roughness effect is more evident than that of the porosity strategy. In the low and medium porosity areas, we can see a better performance of the porosity strategy, at points F and G, with wind speed increased by 2m/s.

At 100 metres, there is an improvement in comparison to the last experiment, due to the increase of the porosity in the top floors of the towers, which previously blocked the wind. The high permeability of the high-rise buildings showed a significant improvement in the urban ventilation, allowing air flow to pass through the patch.

At 150 metres, an overall optimisation of the urban ventilation was achieved thanks to the permeability of high-rise morphologies, and it can also be seen that the increase of air flow on the top layer of the patch redirected wind flow to the lower levels.

patch scale: experiment 1 and 2

Fig.6.20: Existing Patch

6.2

patch scale: experiment 1 and 2

Fig.6.21: Patch - Experiment 2 Output

EXPERIMENTS COMPARISON 6.3

Primitive Input Experiment 1

Experiment 2

EXISTING PATCH

Ops Atot ex= 236.844 m²

Vtot ex= 17.234.980 m³

- Double Existing Public space (Ratio ex = 1.66 m²/inhab.)

GOALS

- Reallocate min 40% of V removed

- V disruption <= 20% of Vtot ex

Ops Atot Exp1= 399.050 m²

Vtot Exp1= 12.849.396 m³

Ratio 1-Ops = 3.15 m²/inhab.

V1 growth= 1.117.395 m³ (= 20.30% of V2 removed )

V1 disruption= 4.385.584 m³ (= 25.5% of Vtot ex)

V1 removed= 5.502.979 m³

Ops Atot Exp2= 393.810 m²

Vtot Exp2= 13.627.673 m³

Ratio 2-Ops = 3.10 m²/inhab.

V2 growth= 1.823.430 m³ (= 33.6 % of V2 removed )

V2 disruption= 3.607.308 m³ (= 21% of Vtot ex)

V2 removed= 5.430.738 m³

EVOLUTIONARY OUTPUT

RESULTS

VOLUME & OPEN SPACE

Overall, the initial architectural target to minimise disruption at 20 per cent in the urban fabric has been achieved. Although the volume removed in Experiment 1 and 2 is almost equal, the outcome of Experiment 2 is better in terms of maintaining high density in the urban tissue. Indeed, the volume added through the growth strategy in Experiment 2 is almost 11 per cent of the initial original volume, whereas Experiment 1 shows a growth around 6 per cent. Additionally, even though the total surface area of open public space is slightly smaller in Experiment 2, generally in both cases the ratio of open public space per inhabitant is doubled in comparison to the existing situation. Ultimately, another important point is that the range of sizes of open spaces is more varied in Experiment 2 than Experiment 1, thanks to the smaller degree of pixilation of buildings and the application of larger gridded plans to morphologies, nearby public transportation nodes.

URBAN VENTILATION

The evolutionary outputs have been analysed with a CFD simulator on the patch scale without considering the surrounding context. Thus, the complexity of the existing topography of Hong Kong was not included; as a consequence, these simulations did not consider the drag effect. The comparison of the results between the existing patch and both experiments showed how the different strategies and their parameters positively or negatively affect urban ventilation.

It was difficult to observe any improvements in air flow at the ground-floor level, and for this reason it would be important to further consider the air flow efficiency of the porosity strategy at this level, as well as whether this permeability should only have social and architectural input criteria. However, the high porosity applied at multiple levels has shown a positive impact on urban ventilation, due to its capability of transferring air flow from the top levels to the

lower levels. Finally, the most relevant result is that the porosity strategy applied to the highrise morphologies could allow a cross ventilation between the eastern and western parts of the urban patch.

Tab.6.6: Experiments results comparison

PATCH

EXPERIMENTS COMPARISON 6.3

URBAN VENTILATION ANALYSIS OPTIMIZATION

1

AA | EmTech | 2013-14 | Dissertation

Adaptable Morphodynamics

Adaptable Morphodynamics

Fig.6.23: Comparison of CDF analyses between Existing patch, Experiment 1 and 2

EXPERIMENTS COMPARISON 6.3

EXISTING PATCH

URBAN VENTILATION ANALYSIS OPTIMIZATION

EXPERIMENT 1

EXPERIMENT 2

100 metres

5 m/s 0 m/s Wind Direction EAST

5 0 m/s

5 m/s 0 m/s Wind Direction EAST

5 0 m/s

AA | EmTech | 2013-14 | Dissertation

(a) 100 m Height

(b) 150 m Height

150 metres

Adaptable Morphodynamics

Fig.6.24: Comparison of CDF analyses between Existing patch, Experiment 1 and 2

COMPUTATIONAL TOOLS

The computational algorithm defined in Grasshopper and associated with the Octopus’s evolutionary engine had some restrictions in terms of the number of primitive geometries that it was possible to import and the degree of complexity of the genotype and phenotype. Thus, it was not feasible to run the experiments by connecting the entire patch at once. It has been necessary to divide it into six parts, each composed of 20 or 30 blocks, in order to finalise the overall result.

As a consequence, the six areas were each developed individually according to specific communal criteria of the general evolutionary strategy. After ranking all generations, the individuals selected for each area were aggregated to compose the final morphological output of the whole patch.

LIMITATIONS 6.4

To conclude, the difficulty of connecting a great number of geometries to the algorithm could lead to less accurate results on a global scale, due to the fact that the interdependence of each patch’s part is not taken into account for the optimisation. Furthermore, the timescale could represent an additional restriction for further developments with a higher level of complexity, considering that each of the current experiments was run over one week and an additional few days were necessary to extract numeric data and evaluate the results.

FLUID DYNAMIC ANALYSIS

There is no straight connection between the Computational Fluid Dynamic analysis and the computational tools, so it was not possible to directly optimise the building morphologies for the wind by using multi-objective criteria for the evolutionary algorithm. This is the reason for exploring several ventilation strategies in order to extract geometrical parameters that could be easily integrated into the GH definition to indirectly achieve an acceptable wind performance.

Moreover, the CFD analysis did not provide accurate results because of the low resolution on an urban scale. As a consequence, we run several analyses to test the wind performance at different scales because results are more precise at the block and building scale. Overall, the wind analysis mainly worked as a visualisation tool for the performance of the urban ventilation through the use of the porosity strategy.

Fig.6.25: View from the seafront

existing and modified patches, it can be seen how the pedestrian circulation is affected by the percentage of permeability. Indeed, it is expected that an increase in the amount of the floating population, due to the emergence of new open spaces. For this reason, it is evident from both experiments how more porosity at the ground floor level improves mobility around the urban tissue through fluid, accessible and interconnected pedestrian paths. This factor could have a great importance in encouraging inhabitants to use alternative and sustainable means of transport for short journeys.

ANALYSIS PEDESTRIAN FLOW - GROUND LEVEL

Adaptable Morphodynamics

Fig.6.26: Depth map AnalysisPedestrian flow at ground level, Existing and Experiment 1

EXPERIMENT EXISTING

AA | EmTech | 2013-14 | Dissertation

POROSITY AND PEDESTRIAN CIRCULATION 6.5

ANALYSIS PEDESTRIAN FLOW - GROUND LEVEL

Adaptable Morphodynamics

Fig.6.27: Depth map AnalysisPedestrian flow at ground level, Existing and Experiment 2

7. EXPERIMENT 2: BLOCKS AGGREGATION

EXPERIMENT 2: BLOCKS AGGREGATION Scale 7.

Three different sub-areas, located in significant points of interest, were extracted from the urban fabric with the intent to explore the architectural and environmental qualities of the emergent morphologies at block and building scale. The aim was to analyse three diverse scenarios in terms of typology, density and environmental performance.

SUB-AREA 1

SUB-AREA 2

SUB-AREA 3

Fig.7.1: Exisiting and Experiment 2 Sub-areas, Location in patch

EXISTING CONDITIONS

Sub-area 1 is situated on the north-eastern part of the patch and it has a mix of high-density low- and medium-rise buildings. This zone is characterised by a lack of open spaces and inadequate housing. Indeed, an increased number of illegal informal settlements, known as rooftop villages, can be found. Moreover, a medium flow public transportation node, the Sham Shui Po underground station, is located nearby.

EVOLUTIONARY COMPUTATIONAL OUTPUT

As result of the application of a porosity gradient (from low to high), the sub-area was provided with new open spaces with respect to the existing condition. Public, semi-public and semiprivate open spaces were classified according to specific dimensions in order to define their function and scale of influence. In particular, larger portions of open public spaces next to the public transportation node could bring about benefits to the existing poor housing by stimulating social regeneration and inclusion— locally and in all neighbourhoods.

SOLAR EXPOSURE

A solar analysis was run on the buildings on a smaller scale to get a clear insight into the local micro-climate of the emergent voids over the hottest season, from June to September. It can be seen that open spaces, which are more enclosed, become shaded, whereas the rooftop surfaces of tallest buildings are the most exposed to the sun.

Fig.7.2: Sub-area1, Existing conditions, solar exposure analysis

MORPHOLOGIES - EMERGENT FUNCTIONS

Existing and new functions could be accommodated in the volume added to the buildings, and in the voids left by the volume removed. The growth strategy applied to the rooftop surfaces of low- and medium-rise buildings could be translated into a series of new morphologies, able to house new programmes, such as micro-economy and social provisions. For example, as illustrated in the diagram below, a sky farm can be defined when the growth in medium- or high-rise building blocks has a high percentage of no built-up areas. These building typologies could be more adequate than lower buildings for farming activities, because, as

shown from the solar radiation analysis, their rooftop surfaces are more exposed to the sun. In addition, the porosity at the ground level can generate space for temporary or permanent open street markets, directly connected with the micro-economy located above.

Public and semi-public activities that require both indoor and outdoor spaces, such as cultural and social provisions, can be housed on the top of low-rise buildings when the percentage of grown volume and open space is nearly equal. These buildings are shaded by their surroundings, and this factor positively contributes to the

thermal comfort of open spaces. In addition, their reduced height allows public services and facilities located on the top to be easily accessible to users.Finally, medium and small voids, placed on the middle levels of buildings, could accommodate semi-public communal areas with facilities and semi-private skygardens, whereas larger areas of open space could be dedicated to public activities, such as exhibition and social gathering, or to vertical gardens for informal and passive recreation.

Fig.7.3: Sub-area1, Existing conditions, solar exposure analysis

MULTI-LAYERS OF CONNECTIVITY

This cluster connects eight blocks through a series of vertical and horizontal footpaths. This network has a circulation and leisure character and it connects the emergent public spaces in the cluster at all levels. The linkage between large areas of public spaces within the is comprised of high flow connections, while a lower level of connectivity is used on the building scale .

The cluster provides direct accessibility to the MTR tube station, which is characterised by an increase in the amount of floating population.

For this reason, we proposed a series of connections that vary according to each function and the level of population’s flow per hour.

Fig.7.4: Sub-area 1, Multilayers of connectivity, flow profiles

COMPUTATIONAL FLUID DYNAMIC

A 3D CFD simulation was carried out to analyse the effect of the strategies on urban ventilation. We analysed four urban sections in order to quantify the effects of the parameters on different buildings’ morphologies. The high presence of rooftop villages and social services negatively affected the wind ventilation, because these buildings were not included in the porosity and roughness strategies. In addition, it can be observed that the increased buildings’ height at points A, B, C and D caused a reduction in air flow at the canopy layer due to the roughness

strategy. However, at points 1, 2, and 3, an increase in the amount of air flow can be seen at the block scale as a result of the porosity strategy.

MICRO-CLIMATE & ARCHITECTURAL QUALITY OF OPEN SPACES

The resulting morphologies have been analysed further in order to identify the quality of open spaces and define the potential activities that these spaces could house, according to their

thermal comfort, size and the number of users. Thus, areas characterised by a wind speed greater than 3m/s, could be suitable for water collection and vegetation cover to mitigate the Urban Heat Island effect. On the other hand, open spaces with a value of air flow between 0 and 3m/s could be considered zones for leisure and recreational activities.

Section Existing Patch

Section Experiment 2 Minimum Solar Exposure

Experiment 2 Minimum Solar Exposure

Fig.7.5: Sub-area1, CFD Analysis, Sections: Existing and Experiment 2

Fig.7.6: Architectural approach to the emergent open space

EXISTING CONDITIONS

Sub-area 2 is located in the north-western part of the patch and is characterised by a combination of high-density low- and medium-rise buildings. Although this area has poor housing, for instance rooftop villages and no public spaces, it has a school as a main social feature.

EVOLUTIONARY COMPUTATIONAL OUTPUT

Sub-area 2 showed a massive increase in the number of public and semi-private open spaces, completely lacking in the existing urban tissue. Furthermore, the total surface area of semipublic space rose considerably from 2.817 m² to 18.865 m². This was possible thanks to the application of a high porosity gradient to different blocks.

SOLAR EXPOSURE

The solar radiation analysis for sub-area 2 showed results similar to those of sub-area 1, due to the presence of buildings with the same ranges of height. While the enclosed open spaces are shaded, the square, where the school is located, is highly exposed to the sun.

Fig.7.7: Subarea 2, Existing conditions, solar exposure analysis

MORPHOLOGIES - EMERGENT FUNCTIONS

The increased volume could accommodate new housing, allowing reallocation of part of the initial residential volume removed through the porosity strategy. For instance, this could happen when the percentage of built volume is significantly greater than that one of open areas. Moreover, other public or semi-public programmes that necessitate larger outdoor spaces, such as sportive centres or open green areas, could also be located on the rooftop level of low- and medium-rise building blocks because they are more shaded. Finally, communal areas and semi-

private terraces, for exclusive use of residents, could be placed on the top floors of buildings.

Fig.7.8: Sub-area 2, Existing conditions, solar exposure analysis

MULTI-LAYERS OF CONNECTIVITY

This area has a low flow level of connectivity, thus blocks are not linked to each other. Only buildings that belong to the same block connect to one another, providing internal access to several types of open spaces, located on multiple levels. This vertical and horizontal circulation generates a dynamic pedestrian network that connects the communal and public spaces in each block.

Fig.7.9: Sub-area 2, Multilayers of connectivity, flow profiles

COMPUTATIONAL FLUID DYNAMIC

The height profile of the existing area has only increased in some buildings due to the growth strategy. As shown from the image above, this can be noticed at specific points, such as A, B, C and D, whereas a greater number of open spaces can be found at points 1,2 and 3. In this area, it is observed how the variation in building height is balanced with the porosity, which opens up the buildings at the top-floor levels. This allows air flow to be redirected from the urban canopy to the pedestrian level, improving the outdoor environmental conditions.

MICRO-CLIMATE & ARCHITECTURAL QUALITY OF OPEN SPACES

In sub-area 2, open spaces characterised by a value of air flow from 0m/s to 1m/s could be considered as areas for leisure activities, while wind speeds higher than 3m/s could define wetlands zones, composed by ponds for the collection of rainwater and greenery. These elements could create urban biodiversity and a natural environment within the cityscape. Finally, enclosed areas, characterised by a moderate air flow between 0m/s and 1m/s, could host commercial activities or other functions, such as street markets and open-air galleries.

Fig.7.10: Sub-area 2, CFD Analysis, Sections: Existing and Experiment 2

Existing Patch

Fig.7.11: Architectural approach to the emergent open space

EXISTING CONDITIONS

Sub-area 3 is located on the southern part of the patch, next to a high-flow tube station, Prince Edward. The zone is mainly constituted by highdensity high-rise building blocks and towers, characterised by low permeability and a mixeduse (residential and commercial) programme.

EVOLUTIONARY COMPUTATIONAL OUTPUT

In sub-area 3, high porosity has been applied to the existing morphologies in order to facilitate the air flow through the patch, previously blocked by the ‘wall effect’ of the towers. Subarea 3 showed a substantial rise in the number of semi-private open spaces and an increase of around 40 per cent of the original amount of public and semi-public open spaces.

SOLAR EXPOSURE

As can be seen from the solar radiation analysis below, the enclosed open spaces in high-rise building blocks and towers are characterised by an average value of solar exposure. These spaces tend to be less shaded because of the higher permeability of buildings and the less compact nature of the urban fabric.

Fig.7.12: Sub-area 3, Existing conditions, solar exposure analysis

MORPHOLOGIES - EMERGENT FUNCTIONS

No growth is applied to the towers to avoid increasing their height further, which would be a problem for the passage of wind. The emergence of voids underneath the towers functions to allow air flow through the urban fabric. Enclosed open spaces, such as public gardens with facilities or multipurpose plazas, are public at lower levels because they are easily accessible by users, whereas semi-public open spaces are located on top floors.

The open spaces, which are more exposed to sun and wind, are not publicly accessible; however, their integration with greenery, in the form of green roofs, has environmental purposes, such as absorbing humidity and pollution to decrease temperature. On the other hand, the podium structures are broken through a porous system that creates public crosswalks and urban infill, such as small and medium-sized plazas underneath.

Finally, larger areas of public open spaces emerged because of the aggregation of several high-rise building blocks into a cluster, nearby public transportation node. These spaces could allow for the accommodation of an increased number of users.

Fig.7.13: Sub-area 3, Existing conditions, solar exposure analysis

MULTI-LAYERS OF CONNECTIVITY

This area has a high-flow level of connectivity and it is formed by the aggregation of seven blocks into a cluster. Different building morphologies are interconnected internally between different blocks and to the existing secondary layer. Large areas of open space in the cluster are connected to other public spaces, located at lower levels of the high-rise buildings. This creates a system of public spaces that gives additional value to the outdoor pedestrian network. Finally, the mutual use of high, active and low-flow links, according to specific areas, is extremely important to

accommodate an estimated population of over 20,000 inhabitants.

Fig.7.14: Sub-area 3, Multilayers of connectivity, flow profiles

COMPUTATIONAL FLUID DYNAMIC

Sub-area 3 is characterised by high-rise buildings,high and medium-rise building blocks, and some social provisions. The existing towers, located in the west, block the wind coming from the coast, generating a sort of wall effect. By applying the previous strategies, we predicted to be able to increase urban ventilation through the patch at several height levels. It is noticeable that the general profile of buildings considerably changed in the area. Indeed, the highest porosity of towers at the top-floor levels increased air flow from 0m/s to 3m/s, allowing the air flow to pass through the buildings and

reach other parts of the patch. Although the increase in building height caused a decrease in wind speed, observed only at points A and B, the emergence of open spaces at points 1, 2, 3 and 4 had considerably redirected air flow to other areas at the urban canopy layer. As a consequence, this last factor could reduce high temperatures during the summer in order to provide citizens with a comfortable outdoor environment.

MICRO-CLIMATE & ARCHITECTURAL QUALITY OF OPEN SPACES

As a result of the applied strategies, the highrise morphologies show a variety of open spaces, which differ for architectural quality and dimensions. In this specific case, the emergence of public activities will be possible only when wind speed is lower than 1m/s and the spaces are semi-enclosed.

However, areas in which wind speed exceeds the value of 3m/s could be used strictly for water collection; at this height, only low vegetation could be employed to regulate the patch’s micro-climate.

Section Existing Patch

Section Experiment 2 Minimum Solar Exposure

Experiment 2 Minimum Solar Exposure

Fig.7.15: Sub-area 3, CFD Analysis, Sections: Existing and Experiment 2

Fig.7.16: Architectural approach to the emergent open space

ALBEDO

Our approach on the emergent open spaces is to propose a configuration of surfaces with high albedo levels that could affect the microclimate created by the urban heat island effect. Several materials with high reflective properties will be integrated into the open spaces to improve environmental conditions by reducing the absorption of the solar energy. The materiality of the surfaces could also define the character of the spaces. The albedo value ranges from 0 to 1. The value of 0 refers to a blackbody, a theoretical media that absorbs 100% of the incident radiation. Albedo ranging from 0.1–0.2

Albedo

refers to dark-colored surfaces, such as rough soil, while the values around 0.4–0.5 represent smooth, light-colored soil surfaces. The albedo of snow cover, especially the fresh, deep snow, can reach as high as 0.9. The value of 1 refers to an ideal reflector surface (an absolute white surface) in which all the energy falling on the surface is reflected (Matthews, 1984).

The Surface roughness defines the type of reflection. Shiny, smooth surfaces, like a body of water, plant leaves or wet soil surfaces have a high performance on reflectivity and therefore

the proposal includes water collection and low vegetation on the emergent open spaces. In areas where no reflectivity is required, rough surfaces could be used due to their low albedo values.

The overall strategy met the initial aim to minimize disruption to around 20% and it almost achieved the relocation target of 40%. The results of the most recent experiment showed that the Growth strategy recovered 33.6% of the Volume removed but the increase in the number of floor reduced the urban ventilation performance with respect to the previous experiment.

The global optimization of the buildings’ morphologies shows an increase in urban ventilation only at the top floor levels’ of the patch. Some areas, such as in subarea 1, showed no improvement due to the existence of the rooftop villages. In other areas, where the porosity strategy was applied on the high rise towers there was a significant increase in airflow throughout the patch. The CFD analysis demonstrated the overall performance of the airflow but the result tends to vary in accuracy due to the scale and resolution. However, as shown by the experimental results, any porosity will increase air flow but only changes that allow the entrance of airflow from the top levels towards the ground floor can make a relevant improvement on the overall the patch.

design evaluation

As a result, the ratio of open space per inhabitant has been doubled thanks to the porosity strategy for the maximization of the airflow. Although the differentiation in size and functions of the emergent and distributed open spaces brings about diversity in the patch, their location on multiple levels could require a higher complexity of vertical connections to allow a fluid pedestrian mobility.

A further analysis of the local urban microclimate at the building scale could establish better relations between the location of functions, human thermal comfort and quality of the emergent public spaces. The evolutionary genetic algorithm could be refined in order to apply a killing strategy for open spaces and volumetric mass that do not satisfy requirements of size, daylight and thermal comfort.

In addition, building morphologies could be explored over a larger number of generations and seasonal intervals of time, in order to achieve a greater morphological diversity and classify spaces according to their adaptability to different climate conditions, uses and accessibility.

further development

Finally, a thermal analysis on the existing buildings’ envelope could be run to get an understanding of the properties of the materials and their reaction to the indoor and outdoor microclimates. Materials with a high solar reflectance (high albedo index) could be adopted for the major urban surfaces such as rooftops, streets, sidewalks, so as to evaluate their cooling energy effect by directly decreasing the heat gain through a building’s envelope and by lowering the overall urban air.

CONCLUSION

Adaptable Morphodynamics has presented an urban system that enables environmental and spatial qualities through the metamorphosis of urban forms. The site’s climate conditions and social context in Hong Kong played a key role in informing the entire design process in each phase. This lead exploration into new ways of enhancing the existing urban space in relation to urban ventilation and architectural logics. The resulting diversity of new functions and urban microclimates in the emergent open spaces dematerialized the homogeneity of the original patch, by generating a contemporary cityscape able to adapt to the demands of a demographic population density.

hong kong’s water supply 1.

Dongjiang Fresh Water Resources: Imported vs Local Supply (1965 - 2012)

Environmental Problems - Water Supply

Hong Kong’s Water Resources (2012) *

Hong Kong’s Future Water Resources (2020) *

* Source: 2014, Liu S., Williams J.,“Different Approaches to water dependency”

Adaptable Morphogenesis

connectivity: network hierarchy - urban/regional 5.

EXPERIMENT 1: morphologies

EXPERIMENT 1: morphologies 6.

EXPERIMENT 1: morphologies

AA | EmTech | 2013-14 | Dissertation

EXPERIMENT 1: patch scan- open spaces at podium level 6.

PATCH SCAN PODIUM- CLUSTERS

Adaptable Morphodynamics

EXPERIMENT 2: OCTOPUS DATA 6.

HIGH POROSITY AREA A1.1

FITNESS

EXPERIMENT 2: OCTOPUS DATA 6. HIGH POROSITY AREA A1.1

EXPERIMENT 2: OCTOPUS DATA 6.

HIGH POROSITY AREA A1.2

FITNESS CRITERIAVOLUMESUN EXPOSURE

GENERATION 1INDIVIDUALG1.01G1.02G1.03G1.04G1.05G1.06G1.07G1.08G1.09G1.10

V2314499.9952304458.0662277438.0972308741.7292321477.9732310208.7442324929.6892276565.0842294794.2342293378.326 SE0.7752550.7751580.7744340.7748060.7759040.7747210.7759310.7755610.7762390.775274

GE109529.5996109646.8081109430.9272109517.1701109577.46109540.7879109605.1147109656.7638109657.6045109583.5126

GENERATION 2INDIVIDUALG2.01G2.02G203G2.04G2.05G2.06G2.07G2.08G2.09G2.10 V2307209.9412304379.8442303200.1492311199.1062327241.8932310207.7262290452.7252321937.7192335993.5432306297.708 SE0.7752870.7744670.7750240.7752070.7748640.7760160.7747390.7759380.7738090.775795

GE109475.4348109646.5697109649.9703109644.4211109639.2521109588.1701109540.736109610.8121109594.8329109585.6151

GENERATION 3INDIVIDUALG3.01G3.02G3.03G3.04G3.05G3.06G3.07G3.08G3.09G3.10 V2330133.3522312480.1912309637.8332311091.4172304291.1282321335.1322302388.0512305715.8052309060.0112314541.576

EXPERIMENT 2: OCTOPUS DATA 6.

EXPERIMENT 2: OCTOPUS DATA

HIGH POROSITY AREA A1.3

EXPERIMENT 2: OCTOPUS DATA 6. HIGH POROSITY AREA A1.3

GENERATION 8INDIVIDUALG8.01G8.02G8.03G8.04G8.05G8..06G8.07G8.08G8.09G8.10

V5874356.4685812610.3145818729.8045845392.0485874073.7985848744.4795806647.15853888.7375827723.6935851506.902 SE0.7776420.7777440.7778780.7769140.7769030.7773640.7775070.7770.7777590.77738

GE297357.7625297226.6312297244.258297073.0573297243.6687297361.7456297362.3037297270.0051297302.2957297287.9302

GENERATION 9INDIVIDUALG9.01G9.02G9.03G9.04G9.05G9.06G9.07G9.08G9.09G9.10

V5814766.5585822696.7975837101.5195830373.3945803840.4595865145.6965804432.7965817886.7835810058.9835821343.569 SE0.7775480.7775040.7763990.7785150.7774670.7767310.7772750.7773820.7771610.777296

EXPERIMENT 2: ranking 6. high POROSITY AREA A1

EXPERIMENT 2: ranking 6.

high POROSITY AREA A1

EXPERIMENT 2: OCTOPUS DATA 6. MEDIUM POROSITY AREA A2.1

FITNESS CRITERIAVOLUME SUN EXPOSURE

GENERATION 1INDIVIDUALG1.01G1.02G1.03G1.04G1.05G1.06G1.07G1.08G1.09G1.10 V2067416.2662064133.9122100802.162067685.0152062421.6842075397.7282061925.162070419.6562095154.0922096120.33 SE0.7753910.7779450.7753530.7771660.7758620.7763780.7760530.7763440.7755610.775423 GE108946.9874109120.3663109036.6612108323.1209108959.208108401.4894109141.1344108242.5034108940.20810 8973.2104

2INDIVIDUALG2.01G2.02G203G2.04G2.05G2.06G2.07G2.08G2.09G2.10 V2065619.4332065383.1992102253.7322075988.2492089540.2032084982.1122095237.9692094525.7422070393.6092095804.512 SE0.7779160.7764490.7755430.7764120.7766550.7759480.7751750.7752890.7760690.775556 GE109040.1667109000.794109045.2296108433.3196108564.1225108805.7937108954.8861108915.2158108249.1155108911.8883

EXPERIMENT 2: OCTOPUS DATA 6.

MEDIUM POROSITY AREA A2.1

EXPERIMENT 2: OCTOPUS DATA 6. MEDIUM POROSITY AREA A2.1

GENERATION 15INDIVIDUALG15.01G15.02G15.03G15.04G15.05G15.06G15.07G15.08G15.09G15.10

V2099523.4752106042.9982112358.5962099970.8082104485.3412096021.8612105391.8632104167.1822117886.4982090828.412 SE0.776430.7764020.7776590.7759440.7766490.7761940.7766850.7769510.7755490.77698 GE109077.7927109145.5577109055.3205109011.1874109117.55109143.9158108643.3857108587.2996109136.6883109032.3323

GENERATION 16INDIVIDUALG16.01G16.02G16.03G16.04G16.05G16.06G16.07G16.08G16.09G16.10

V2105721.9412111455.5062104392.7322102380.9292101724.4572108558.252110059.7662103795.2182111641.2722111768.591 SE0.7768210.7774350.7766490.776580.7766040.776650.7777280.7765560.7763960.775313

MEDIUM

FITNESS CRITERIAVOLUMESUN EXPOSURE

GROUND EXPOSURE GE

GE47709.3715247678.5307847655.1666847712.1467447674.4404847723.3412747700.6686347686.3025847667.5665747698.57399

POROSITY AREA A2.2

EXPERIMENT 2: OCTOPUS DATA 6.

GENERATION 8INDIVIDUALG8.01G8.02G8.03G8.04G8.05G8..06G8.07G8.08G8.09G8.10

V664690.8749661637.4395660803.4829658827.2092662525.7185661772.2412659908.2633664685.6376657767.2406658024.5887

SE0.7876040.7876250.7882220.7877610.7871890.7872840.787770.7881880.7880750.78769

GE47707.4984947654.3757247658.6949947664.920747714.655147693.7856147649.5399747702.1284947672.4422747696.36561

GENERATION 9INDIVIDUALG9.01G9.02G9.03G9.04G9.05G9.06G9.07G9.08G9.09G9.10

V668119.7008666580.6333659416.4801667263.3483660780.835666774.9035659464.1134663719.7324664487.3585660308.5133

SE0.7881280.7872460.7879460.7879090.7870810.7882390.7880240.7869160.7878580.787789

GE47728.3671947737.5038747631.4670447759.1934347687.2803247721.8145847668.3629247717.9510947664.7293347642.92286

GENERATION 10INDIVIDUALG10.01G10.02G10.03G10.04G10.05G10.06G10.07G10.08G10.09G10.10

SE0.7894190.7877220.7880240.7881790.78810.7875210.7885890.7886150.7869190.788328 GE47718.2969247715.5227347731.2694447721.7043447760.7138247728.2420247750.4395347747.1926647737.9169547756.68634

GENERATION 14INDIVIDUALG14.01G14.02G14.03G14.04G14.05G14.06G14.07G14.08G14.09G14.10

V667595.7539667568.8316669780.0886668114.8075666344.6704666699.3292665651.5468666433.186666704.038665195.2793

SE0.7882290.7886120.7883360.7884830.7885360.7885890.7886070.7877450.7887370.787777

GE47748.037747761.3884747756.4163747727.447647737.4087847749.477647744.1028547757.6894347740.093247761.19132

MEDIUM POROSITY AREA A2.2

EXPERIMENT 2: ranking 6. V SE GE G5.01 G5.02 G5.03 G5.04 G5.05 G5.06 G5.07 G5.08 G5.09 G5.10

V SE GE G8.01 G8.02 G8.03 G8.04 G8.05 G8..06 G8.07 G8.08 G8.09 G8.10 V SE GE G11.01 G11.02 G11.03 G11.04 G11.05 G11.06 G11.07 G11.08 G11.09 G11.10

V SE GE G14.01 G14.02 G14.03 G14.04 G14.05 G14.06 G14.07 G14.08 G14.09 G14.10

V SE GE G19.01 G19.02 G19.03 G19.04 G19.05 G19.06 G19.07 G19.08 G19.09 G19.10 V SE GE G1.01 G1.02 G1.03 G1.04 G1.05 G1.06 G1.07 G1.08 G1.09 G1.10

V SE GE G5.01 G5.02 G5.03 G5.04 G5.05 G5.06 G5.07 G5.08 G5.09 G5.10

V SE GE G14.01 G14.02 G14.03 G14.04 G14.05 G14.06 G14.07 G14.08 G14.09 G14.10

V SE GE G19.01 G19.02 G19.03 G19.04 G19.05 G19.06 G19.07 G19.08 G19.09 G19.10

V SE GE G8.01 G8.02 G8.03 G8.04 G8.05 G8..06 G8.07 G8.08 G8.09 G8.10 V SE GE G11.01 G11.02 G11.03 G11.04 G11.05 G11.06 G11.07 G11.08 G11.09 G11.10

FITNESS

EXPERIMENT 2: OCTOPUS DATA 6. LOW POROSITY AREA A3

V1157617.6141161191.4821162313.2941158586.421160401.6531160982.4311159506.2451160798.4051163076.511160315.593 SE0.7987810.7993660.7991420.7997980.7994950.7995240.8001880.7990040.7994590.799882

GE82417.2141282484.339282424.8617382449.3226182425.1780382415.9247382509.1677282464.6243282490.7921782424.91952

EXPERIMENT 2: ranking 6. V SE GE G5.01 G5.02 G5.03 G5.04 G5.05 G5.06 G5.07 G5.08 G5.09 G5.10

V SE GE G8.01 G8.02 G8.03 G8.04 G8.05 G8..06 G8.07 G8.08 G8.09 G8.10 V SE GE G11.01 G11.02 G11.03 G11.04 G11.05 G11.06 G11.07 G11.08 G11.09 G11.10

V SE GE G14.01 G14.02 G14.03 G14.04 G14.05 G14.06 G14.07 G14.08 G14.09 G14.10

V SE GE G19.01 G19.02 G19.03 G19.04 G19.05 G19.06 G19.07 G19.08 G19.09 G19.10

Fitness Criteria

Genetic algorithm definition :Experiment

Data exchange between rhino and grasshopper plataform.

Lady Bug plug-in for Solar and Ground Exposure optimization.

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