Exploring the applicability of vernacular architecture for contemporary low-cost housing in Addis Ab

The University of Westminster, College of Design, Creative and Digital Industries School of Architecture and Cities MSc Architecture and Environmental Design 2018/19 Sem 2&3 Thesis Project Module

“Exploring the applicability of vernacular architecture for contemporary low-cost housing in Addis Ababa� - Ethiopia

Hyab Ariam Amare London, September 2019

Figure 1 community based design

ABSTRACT

The paper aims to highlight and quantify the environmental impact of the housing demand in the city of Addis Ababa. The pressure on the housing sector has increased due to the unprecedented rate of population growth, which has put a demand on the lowest income sectors. The vernacular housing built with ‘Chika’ (mud and wood) makes up approximately 70-80% of the current total housing stock, including the government-owned ‘kebele’ (small district within the sub-city) housing as well as informal housing.

The capital has been unable to provide adequate and sufficient housing, particularly for its low-income citizens. More than 90% of the houses are single-storey buildings, which indicate that the use of land is not sufficient. Only 30% of the current housing stock in the country is in a fair condition, with the remaining 70% in need of total replacement, hence the reason for housing schemes.

The Ethiopian government promoted a growing vertical stem of affordable housing in the year 2000. ‘The Condominium Blocks’, the ambitious Integrated Housing Development Programme (IHDP) aims to reduce the shortage of houses of rapid urbanization and create affordable units for middle and low-income groups. The governmental housing project faces the matter of density and provides a fast construction process, e.g. high production cost, no consideration of materiality, import of foreign technologies and building configuration that does not match with the social context.

Responding to the housing challenges in the urban area of Kirkos, the paper aims to find design guidelines for a low- cost housing, considering the traditional way of living and the social networks, that is environmentally responsive by providing thermally adequate indoor and outdoor comfort and exploring the applicability use of the vernacular architecture.

Keywords: Vernacular Architecture, Urbanization, Low-cost housing, Informal settlements; Addis Ababa, Condominium, Thermal comfort

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ACKNOWLEDGEMENTS

Firsty, I would like to thank my thesis advisor Dr Rosa Schiano-Phan, of the MSc Architecture and Environmental Design course at the University of Westminster, who shared my passion for the topic from the start. Her guidance, feedback and judgment helped me structure and do my best work. I also wish to thank the other tutors, Juan Vallejo, Kartikeja Rajput, Amadeo Scofone for the technical advice and valuable comments, and other visiting professionals who also participated in the reviews, for their brilliant feedback and suggestions on my thesis research.

I must also express gratitude to 125 Fund organization at the University of Westminster for funding my field trip to Addis Ababa in Ethiopia. This has granted me the possibilities to explore my research study in depth.

I would also like to acknowledge professor Teddy Tadese, of the Ethiopian Institute of Architecture, Building Construction and City Development (EiABC), at the University of Addis Ababa. For the passionate participation, input and involvement in the research, through site-visits, interviews with environmentalist and household surveys for this research that was successfully conducted.

Finally, profound gratitude to my family and my partner for providing me with unfailing support and continuous encouragement throughout the year of study and through the process of researching and writing this thesis. I’m forever grateful, this accomplishment would not have been possible without them.

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TABLE OF CONTENTS

ABSTRACT-------------------------------------------------------------------------------------------------------I ACKNOWLEDGEMENTS ------------------------------------------------------------------------------------II TABLE OF CONTENTS ---------------------------------------------------------------------------------------III LIST OF FIGURES ---------------------------------------------------------------------------------------------V LIST OF TABLES ---------------------------------------------------------------------------------------------- VI ABBREVIATION AND ACRONYMS-----------------------------------------------------------------------VII GLOSSARY OF TERMS --------------------------------------------------------------------------------------VIII CHAPTER 01 Introduction

1.1. Research question 13 1.2 Structure of the Study 15

1.2.1 Objectives 1.2.2 Theoretical Background

1.2.3 Hypothesis 16 CHAPTER 02 Context Overview 20 2.1 Climate analysis 21

2.2 Profile of Ethiopia 22

2.3 City of Addis Ababa 22-23

CHAPTER 03 Case study

3.1 Site Analysis; Kirkos

3.1.1 Fieldwork Outdoor Analysis

3.1.2 Fieldwork Indoor Analysis

3.2 Vernacular studies ‘Chika-Bet’

3.3 Thermal Comfort- Case study

3.3.1 Frequency Analysis

3.3.2 Daily profiles of representative days

3.4 Design Application

3.4.1 Positive Attributes//Advantage

3.4.2 Negative Attributes//Limitations

3.4.3 Research Outcomes CHAPTER 04 Social Integration of Living Conditions

4.1 Housing Crisis

4.2 The governmental Housing schemes

4.3 The Condominium Housing program

4.3.1 Vertical Living

III

26 26-31 32-33 34 35 36 37 38

42 43-44 45 46

CHAPTER 05 Analytical Work 49 5.1 Methodology For Design 50

5.2 Defining Design principles 51

5.2.1 Massing strategies 51-52

5.3 Program Distribution & Design criteria 53

5.4 Passive design strategies 54-57

5.4.1 Outdoor Studies//Courtyard

5.4.2 Facade Design

5.4.3 Roof design

5.5 Environmental advantages of Rammed Earth

58 5.5.1 Rammed Earth Construction

5.6 Indoor Studies 59

5.6.1 Window Configuration// Design 59-60

5.6.2 Natural Daylight and ventilation 60-61 CHAPTER 06 Thermal Comfort

6.1 Thermal Zoning

6.1.1Frequency Analysis

6.1.2 Daily profiles of representative days

65 66 67 68-69

CONCLUSION ---------------------------------------------------------------------------------------------71-73 BIBLIOGRAPHY-------------------------------------------------------------------------------------------76-77 APPENDICES ----------------------------------------------------------------------------------------------78-82 AUTHORSHIP DECLARATION FORM ------------------------------------------------------------------83

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LIST OF FIGURES Figure 1 Community based design I Figure 1.2.2.1 Structure Diagram 15 Figure 2.1.2 Ethiopia map of Köppen climate classification

20 Figure 2.1.1 Geographical Location Figure 2.1.3 Monthly average climate data 21 Figure 2.1.4 Monthly Rainfall Data Figure 2.1.4 Monthly average global vertical radiation Figure 2.1.5 Total annual radiation Figure 2.2.1 Cities expansion & establishment 23 Figure 3.1.1 Site location 26 Figure 3.1.2 Spot Measurements - Sunny Day 27 Figure 3.1.3 Spot Measurements - Rainy Day Figure 3.1.4 Elevation 1:100 28 Figure 3.1.5 Exisitng Plan 1:100 29 Figure 3.1.6 Sun Path Diagram 30 Figure 3.1.7 Daily average sunlight hours Figure 3.1.8 CFD Figure 3.1.9 Wind Profile Figure 3.1.10 Annual Wind Rose Figure 3.1.11 UTCI- Heat Stress 31 Figure 3.1.2.1 Data logger monitoring 32 Figure 3.1.2.2 Ocupant Spatil Indicator Figure 3.1.2.3 Occupant Survey Figure 3.1.2.4 Usefuul Daylight illuminance 33 Figure 3.1.1 Vernacular Construction 34 Figure 3.1.2 The Evolution of the ‘Chika-bet’ Figure 3.3.1.1 Thermal Modeling 35 Figure 3.3.1.2 Infiltration Through Building Fabric 36 Figure 3.3.1.3 Free running - Basecase - Mud construction Figure 3.3.1.4 Free running - Scenario 1 - Concrete construction Figure 3.3.2.1 January day 16 37 Figure 3.3.2.2 May day 136 Figure 3.3.2.3 August day 226 Figure 3.4.1 Modern Vs Vernacular Courtyard 38 Figure 3.4.2 Socio-Economic network Figure 4.1 Overcrowding in Addis Ababa 42 Figure 4.2 Addis Ababa suveryed district housing Figure 4.2.1 Proportion of non-slum and slum areas 43 Figure 4.3.1 Informal Vs Formal Condominium Housing 45 Figure 4.3.2 Condominium Scheme Figure 4.3.1.1 High-Rise Buildings 46 Figure 4.3.3 Densification of Sub-cities Figure 5.2.1.1 Massing Stages 51 Figure 5.2.1.2 Hourly average horizontal radiation 52 Figure 5.3.1 Programmatic AXO 53 Figure 5.4.2.1 Sunlight study courtyard 54 Figure 5.4.2.2 Roof Design

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Figure 5.4.3.2 Hourly average Horizontal radiation, roof 1.5M and 3M 55 Figure 5.4.3.3 Roof construction Figure 5.4.3.4 Bioclimatic Section 57 Figure 5.5.1 Construction Process 58 Figure 5.5.1.1 Project Feasibility & Cost comparison Figure 5.6.1 Sunlight studies on facade 59 Figure 5.6.1.1 Window Configuration Figure 5.6.1.2 Facade optimasation for solar control 60 Figure 5.6.2.1 Useful Daylight Illuminance 2nd floor 61 Figure 5.6.2.2 Plan 1:100 & typical units 62 Figure 6.1.1 Thermal Modeling & zones 66 Figure 6.1.2 Material properties Table 6.1.1 Internal Condition Rammed Earth 67 Figure 6.2.1 Free Running Base case Figure 6.2.2 Free Running Shading scenario Figure 6.1.2.1 Patio/Corridors 68 Figure 6.1.2.2 January day 16 69 Figure 6.1.2.3 May day 136 Figure 6.1.2.4 August day 226 Figure 6.1.2.5 Earth construction around the world 73

LIST OF TABLES Table 3.1 Table 3.2 Table 4.1.3

Internal conditions of mud house construction 35 Internal conditions of concrete construction Estimated housing needs for 2023 42 Table 4.2.1 Distribution of households by income group 44 Table 5.2.1.1 Mid-rise massing outcome 51 Table 5.3.1 Unit typologies 53 Table 6.1.1 Internal Condition Rammed Earth 67

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ABBREVIATION & ACRONYMS

AAHDAA

AAGHP

AASHDE

AU

CBD

CIS

EBCS

EPRDF

ETB

IHDP

LCH

UN ECA

RH

SDPRP

TAS

UDI

UHI

UN-HABITAT

Addis Ababa Housing Development & Administration Agency Addis Ababa grand housing program Addis Ababa Savings & Houses Development Enterprise African Union Central business district Corrugated iron sheets Ethiopian building Code Standards Ethiopian people’s revolutionary democratic front Ethiopian birr Integrated Housing Development Programme Low cost housing United Nations Economic Commission for Africa Relative humidity Sustainable development and poverty reduction program Thermal modelling software Useful daylight illuminance Urban Heat Island United Nations Human Settlements Programme

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GLOSSARY OF TERMS

VIII

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CHAPTER 01

CHAPTER 01 Introduction

1.1 Research Question How will the use of adobe technology vertically affect the living conditions compared to low rise parallel living? In which way can the scheme be feasible and elevate itself as a resilient standardised construction system?

The master plan design of the city is integrated horizontally, the urbanisation of the city, e.g. offices, housings, malls, and infrastructure was spread out over ground occupying lots of land/acres. Massive and rapid urbanisation increasingly demands more water, energy, food, land and housing, causing rapid land cover change and alterations.

By providing knowledge that contributes to achieving an environmentally sustainable society, and if densification, densifying vertically can be a strategy to re-building the city by saving physical resources and material and construction cost, towards more energy-efficient and environmentally responsive. “Due to rapid urbanisation, densification has become an essential agenda in planning; hence why Building density has an intricate relationship with urban morphology, and it plays a crucial role in forming of the urban form. Ng, E, (2010). Contemporary housing that is climate-responsive can be built and use the resources of renewable energy, using the base principles of abode technique questionnaire, and field studies, that will be undertaken to further implement broad entrance to environmental sustainability in the new urban fabric of the city.

The expeditious rate of urbanisation, population growth and built-up area is increasing rapidly and has had an impact on public housing development and density in Addis Ababa. Though the population density varies from sub-city to sub-city, the centre of Addis Ababa has higher population density compared to the other sub-cities found in peripheral areas. The city’s expansion and growth are affecting the social and economic, as the environmental impact of the housing demand in the city is growing at a higher rate in history; therefore the pressure of the housing sector is massive. (Yeshitela et al., 2019) To justify if vertical densification with an understanding of other methods of construction cost is a way for the future sustainability of the city, also to decrease the displacement of the people. This is to tackle the high growth in population better and to build resilience and enhance adaptation to the impacts of the changes from low-rise housing blocks. ‘Fast rate of urban expansion and built-up area are rapidly increasing in Addis Ababa (Woldegerima et al. 2016)’ Major goal for development is to improve the overall standard of living of the population, by improving housing conditions and construction cost, more development had an impression on the increase on the urban surfaces at the expense of rural and reclaimed land or natural grounds in the capital due to the rapid expansion of the city. Displacing people and putting them to the unknown without considering the environmental protection of the land, also the impact on their social and economic progress. Hailemariam. A (1994)

How is then the country constructing, Is it with an awareness of the future scenarios implementing long term plan for future housing needs i.e. how to further accommodate the extreme high population growth in the city, without compromising future generations or building to build and expand without any consideration of the environment, economic and social factors, and displacing citizens due to reconstruction, development and high growth in population?

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1.2 Structure of the Study 1.2.1 Objectives

Expanding the housing vertically the components of the unit will be fabricated and produced on-site, by the help of the people who will be inhabiting the units and other small businesses giving opportunities to catalyze the local bondage and economies.

The research aims to find design guidelines by exploring the applicability of vernacular architecture, for a low- income contemporary residential housing that is climate-responsive and uses the resources of renewable energy, measuring the attributes to understand the potential and base principles of abode Chika-bet technique. Urban areas are characterized by the coexistence of formal and informal settlements, which primarily attributes “to population pressure on the land, a rapidly growing infrastructure and poor land-use planning” (Feyissa et al., 2018). How to then establish guidelines for formal settlements, respecting the traditional way of living and social networks?

1.2.2 Theoretical Background Traditional buildings: Traditional buildings- a global survey of structural form and cultural functions. By Allen G. Noble: Allen G. Noble investigates traditional dwellings around the world, which has grown more over the years but slowly exchanged by contemporary and modern design. In many cases of development, it is evident that the causes of this are a lack of understanding for the architectural significance, environmental design approach and cultural needs. “Vernacular architecture is an historical and geographical record of a culture groups relationship to physical and social environment”. The author’s work provides a thorough understanding of traditional buildings around the globe with all types of climate conditions, where he discusses building materials and construction methods and reports survey and critical analysis. The study of architecture whether vernacular or formal, allows us as environmental designers the understanding, in the case of traditional building the constancy of concept approaches, the modifications of reflecting changes in culture, environment, socioeconomics and the way of life.

How is the community affected by living vertically, can the vertical city provide security, comfort, and convenience to the residents with a sense of belonging to a community with a private function and most importantly not being displaced to the unknown?

As the cost of building materials accounts for the most substantial proportion of the overall construction cost, innovating low-cost building material is vital. The objective is to use available and local materials to create links between communities and designers, to implement and combine their different capacities. The study promotes cost-efficient housing construction technology by, creating links between vernacular and contemporary housing, to provide low-cost units that further accommodate the extremely high population growth in the city, without compromising future generations.

The second part of this process proposes an alternative to the current government housing projects. Also, designing a dwelling units which brings in collusion data from the fieldwork, case study, simulation and other information collected as a structure for design guidelines.

Figure 1.2.2.1 Structure Diagram 15

1.2.3 Hypothesis Exploring what the challenges faced in the city of Addis Ababa, which suffers from a shortage of housing but mainly from poor quality homes whereby “80% of Addis’ inner-city houses need complete replacement. Growth takes place mainly in slums and informal settlements where infrastructure and access to services are limited or nonexistent (see fig 1.2.2.1 structure diagram). If the vernacular has positive attributes that can be applicable for contemporary design, then the effectiveness to moderate indoor air temperature and comfort will be achieved and reduce the construction cost of housing units. By considering the techniques of vernacular technology building from horizontal to vertical will potentially also have a high reduction on the consumption of energy, support the growth in population and preserve the horizontal areas for cultivation and recreation. (Hjort & Sendabo, 2007) Expected Outcome Would vertical units provide security, comfort, and convenience, Is it a sustainable solution that is meeting criteria to the solution needed for the residents while addressing livable spaces with a sense of belonging to a community that provides residential functions and most importantly the displacement to the unknown.The Vertical units aim to improve housing demand for the high population growth, overlapping two main areas of environmental and socio Economic of the formal settlements, with a potential to prevent displacement.

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CHAPTER 02

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CHAPTER 02 Context Overview 2.1 Climate analysis Ethiopia lies 9.1450° N, 40.4897° E of the equator, between latitudes 3°C, 15 minutes and 18°C north of the equator and between 33°C and 48°C to east. (fig. 2.1.1) The country is in the tropical zone, lying between the equator and the tropic of cancer, it classifies in three major climate zones according to elevation tropics.

Kolla (tropical zone) is bellow 1830 elevation with an average annual temperature of 27°C and an annual rainfall about 510 millimetres. Woina Dega (subtropical zone) include the highlands area of 1830-2440 meters in elevation. An average annual temperature of 22°C and annual rainfall between 510-1530 millimetre.Sega (cool zone) is above 2240 meters in elevation with an average annual temperature of 16°C and annual rainfall between 12701280 millimetre. Köppen-Geiger climate classification (fig, 2.1.2 Köppen, 2019) The country is known as the eleven months of sunshine and categorized with two main seasons, dry season (bega) October to January and wet season. Monsoon the wet season is divided in the long rainy season (kiremt) June to September and the short rainy season (belg) February to May.

Figure 2.1.1 Geographical Location

Figure 2.1.2 Ethiopia map of Köppen climate classification, (Köppen, 2019)

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The capital Addis Ababa lies between latitudes 9°C, 1 minute north and 38°C, 44 minutes east in the cool zone (sega), with an elevation of 2.355 meters and the temperature is uniform throughout the year with an average annual temperature of 16°C. Despite being near the equator the temperature never gets too hot, Indeed, even in the city’s hottest season in May the temperature does not exceed 27 degree Celsius and the temperature is low diurnal fluctuation during wet season. (fig 2.1.3) Fergus Nicol graph was used as a basis to find the adaptive comfort band for Addis Ababa; Tcomf (comfort temperature)=0.53To (prevailing outdoor temperature)+ 13.8 . (Humphreys et al. 2010)

Figure 2.1.3 Monthly average climate data

Addis Ababa exposure to riverine, and flash floods as well as river overflows caused by extreme rainfall events and upper catchment area activities, such as land-use management or scarce watershed planning. The World Bank group, (2015) Vulnerability to flooding is intimately related to residential development encroachment on riverbanks, non-permanent construction materials, i.e. mud and wood, and inadequate drainage systems along roadways. The rainfall caused by the southwest monsoon though June and September (see fig 2.1.4) The annual total radiation is between 854 to 949 kWh/m2 (see fig 2.1.5) mostly coming from the east and west. The global vertical radiation from the south is low in both wet seasons compared to the dry season, (fig 2.1.4). Moreover, higher during the long rainy season (kiremt) on the north compared to the rest of the seasons. The main challenge of outdoor comfort is direct solar radiation, but with simple strategies for a new design of shading, excellent comfort can be achieved.

Figure 2.1.4 Monthly Rainfall Data

Figure 2.1.4 Monthly average global vertical radiation

Figure 2.1.5 Total annual radiation

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2.2 Profile of Ethiopia Separating the four central sub-cities from the six surrounding sub-cities highlights changes between the older and newer parts of the city. (see figure 2.2.1) for the cities expansion since its establishment.

Ethiopia is the second-most populous in Africa, with a population of 104.3 million people, area of 1.100.000 square kilometres and density of 83 inhabitants/km2. It is one of Africa’s largest and most resource-rich states, yet one of the world’s economically least developed countries, poorly developed infrastructure and a small modern sector have hampered the exploitation of significant mineral resources and are at the same time an obstacle to agricultural development. That was for a long time subject to a feudal structure, which in the 1970s and 1980s was partly replaced by a poorly-managed government effort on large-scale government use. Large parts of the country can not be reached through the road network, and much of the agriculture produce for self-storage.

The lowest point at 2326 meters, while the highest rises to 3000 meters above sea level. It is situated on a hilly plain and is Ethiopia’s largest city with a population of 2.739,551 inhabitants in the metropolitan area, according to the 2007 census with an eight per cent annual growth rate.It is home to 25% of the urban dwellers of the country and holds 527m2 of the area in Ethiopia, with a population density estimated to be near 5936.2 per square kilometre available and is the 106th largest urban area in the world, according to Demographia. (larsen et al., 2019) The resident of the city is anticipated to surpass 6.5 million inhabitants in the future. The annual growth rate of the city was estimated to be 3.8%, compared to earlier years where growth has been at 8%. Today the population is estimated to be 7, 823,600 million.

Ethiopia has the lowest degree of urbanization in Africa, and parts of the country are scarce and inaccessible; others are overcrowded concerning their livelihoods (figure...), with a high degree of ecological damage, primarily through deforestation and erosion. Many years of war in several parts of the country, as well as several periods of severe drought, have contributed to the lack of economic and social progress. “Urban and rural population in the current country or area as a percentage of the total population from 1950 to 2050.” (UN, 2018). Today 79% of the population live in slums, it is expected by year 2050 the country will have to provide 61.5 million urban dwellers and right around one-fourth of the people in Ethiopia live in Addis Ababa.

The capital is the political centre of Ethiopia, with the seat of the President, the Prime Minister and the House of the National Assembly, It is also the seat of the headquarters of the African Union (AU) and the United Nations Economic Commission for Africa (UNECA), which makes the city home to countless embassies. Addis Ababa is an essential hub for commerce and transport, as well as having the most important trading centre, where Mercato is Africa’s largest outdoor market. The trading industry has flourished sharply in recent years and considerable investments made in the development of roads and other infrastructure. The city centre has an extremely high density, up to 30,000 people per km2, concentrating around 30% of the population on 8% of the land, generally with poor living conditions. Ng, E. (2010). Due to the expansion of the capital, there has been massive displacement. In 2012, the city administration released a new land lease regulation that classified the capital city into three zones.

2.3 City of Addis Ababa Addis Ababa the ‘New Flower’ was established in the year 1886, and it has both capital and regional status in Ethiopia’s federal system. The city is divided into ten sub-cities, and within the districts, there are 99 subdivisions, the four central sub-cities comprise the oldest portions of the city, Addis Ketema, Arada, Kirkos, and Lideta, occupy only 8% of the city’s total area (5200 ha2). Six significantly larger sub-cities surround these central sub-cities, the outlying sub-cities of Akaki Kitaly, Bole, Kolfe Keranio, Gulele, Nifas Silk Lafto, and Yeka collectively equal 92% of the total area (46,800 ha2).

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Figure 2.2.1 cities expansion & establishment

First Zone is Central Business District (CBD) zone, which is recognised as the main business areas, the second zone is the Transitional zone, these are the places that surround the central which mostly occupied by industries and residential units, the third zone is the Expansion zone, which is considered to be the suburbs of the city, where the city has expanded and continues to expand in the future. People live in a doubled-up household and overcrowded dwellings, due to the unfavourable government policies and rapid growth in population in the urban district parts are resulting from rural-urban migration and some from high natural increase. (Hailemariam. A, 1994)

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CHAPTER 03

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CHAPTER 03 Case Study 3.1 Site Analysis; Kirkos Kirkos, located in one of the four oldest portions of the city is in the middle of the central business district (CBD). It’s one of the densely populated sub-cities covering a surface area of 1472ha and has a population of 235.441 habitats of 161 persons per hectare. The sub-city has eleven kebeles, which consist of the smallest administrative levels in Ethiopia. The site located in Kirkos district house 263 a 1950-60’s building, surrounded with residential housing, small houses and sheds figure 3.1.1 illustrates there are no existing public spaces, and the streets are narrow.

3.1.1 Fieldwork Outdoor Analysis During the fieldwork, outdoor and indoor measurements were undertaken with various instruments in order to better understand the range of microclimate parameters.

Vane Anemometer: Airflow velocity (m/s), Thermohygrometer: Temperature (°C) and Relative humidity (%), Lux meter: illuminance (lux), Datalogger: Temperature and relative humidity recorder, the external Surface Thermistor Probe designed for the measurement of surface temperature (°C) and a Thermal Camera: Locate damp zones and thermal bridging, demonstrated where heat energy is escaping as well. (Which can be found in the appendice)

The old master plan is so densified and congested with many houses and sheds when the city introduced the new master plan a few years ago, many residential housing and shops were majorly affected, and citizens were either displaced into the unknown or left with nothing. The area has continually changed over the years with ongoing demolishment of existing built, road expansions and new upcoming developments.

Two measurements were taken of the courtyard, due to the distance between the courtyard with the entrance and the courtyard where the gardening is located. The local spot measurement (fig 3.1.2) shows on a sunny afternoon in May spot one, two and five (the patio and the courtyard) has the same temperature of 29.5°C, while spot three and four has 1°C higher. Spot two of the courtyard shows accelerated wind speed of 0.5 m/s Spot measurement on a rainy day (fig 3.1.3) shows the patio, and spot five has a degree of 19.8°C, slightly higher than the courtyard that is between 16.8°C - 17.9°C. While spot one of the courtyards has the highest wind velocity of 0.3m/s, and spot two has 0.1m/s this can be related to the obstruction of the trees and plants, the courtyard -3°C below the comfort band.

Plan of the existing site, plot area is 405m2 - the built-up area is 190m2 (fig 3.1.5). There is a total of 15 people living in this plot of land with an area between 15m2-19m2.

Only one of the five rooms have all the facilities needed, while the other four families of three, two or four have to share one kitchen and one bathroom between them, the traditional Ethiopian way of living can be viewed as the concept of co-living.

Figure 3.1.1 Site location

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Figure 3.1.2 Spot Measurements - Sunny Day

Figure 3.1.3 Spot Measurements - Rainy Day

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Front Elevation

Left Side Elevation

Rear Elevation

Right Side Elevation

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Figure 3.1.4 Elevation 1:100

N

Figure 3.1.5 Exisitng Plan & Layout 1:100

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Figure 3.1.6 Sun Path Diagram

Wind profile shows the average annual velocity of 1.2m/s for the single-story houses, and if built up to mid-rise of 4-6 storeys, it achieves 2m/s. (see fig 3.1.9). “Increase of wind speed with height realitve to diffrent ground unevenness“, (Baumbach G. and Grubinger-Rhodes C. (transl), 1996 p.79).

The CFD results indicate the site velocity is low due to the urban morphology, and this affects the aerodynamics, achieving a wind speed is between 1.8-2.2 m/s, another character is also the narrow streets of the site that mitigated the wind speed (fig 3.1.8). The season of January, May and August were analysed, the three-time frame was chosen 10 am, 1 pm and 4 pm to understand the performance of the courtyard as it is highly used throughout the day.

Figure 3.1.7 Daily average sunlight hours The simulation result shows, the brightest sunny day March 8, Average hottest day May 21 and Peak hottest day being March 27. Sun Path diagram shows the high sun angle throughout the site achieves approximately 9 to 10 hours of sunlight in the short and long rainy season while achieving roughly 6 to 9 hours in the dry season (see fig..). The shadow range of the low rise building shows that mostly the buildings overshadow themselves due to the high sun angle. (see appendix for Shadow range//low rise). Solar protection is needed when the sun is on top, and the courtyard will receive the peak and the highest values of instant solar radiation in certain hours.

Simulation results of (fig 3.1.11) illustrator when solar protection is needed in the courtyard. In the afternoon hours of the short rainy season in January, indicates there is slight heat stress and is neutral in the morning. While the hottest month of May, the dry season is mostly neutral, but archives moderate heat stress from 1 pm to 4 pm. The long rain season of August has a combination of neutral and slight heat stress, in the afternoon there is intense heat stress in the courtyard, indicates to be within the comfort band and in the hottest month is slightly above the adaptive comfort with +2-3 degree celsius. Moreover, the next steps of the design process, the issue of heat stress mitigated through a proper roof design, canopy and vegetation.

The average wind speed on is 2.3 (recording from the fieldwork data usually it is lower on-site due to vegetation and fence ), with the prevailing wind direction from east (fig3.1.10). the annual wind rose indicated clam wind speed 4.36% of the time, 382 hours. Each closed polyline shows frequency of 1.9% equals 163 hours. Least windy days of the year are in January and March, while most windy days are in October. Therefore the need for protection strategies during the wet season is critical.

Figure 3.1.9 Wind Profile

Figure 3.1.8 CFD

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Figure 3.1.10 Annual Wind Rose

Figure 3.1.11 UTCI- Heat Stress

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3.1.2 Fieldwork Indoor Analysis The spot measurements on a sunny day show low illuminance levels at spot four with 24lux and spot three 20lux, with a temperature of 24°C. Compared to the rainy day points of measurement there is evidence that the illuminance levels decrease by half, spot four 10lux and spot three 8lux, the temperature is between 21°C-22°C, this is due to the window ratio as well as the patio obstruction.

The rooms achieve +3°C above the comfort band in the sunny day condition.

Three data loggers were placed in room one, three and five to monitor ten days continuous to understand and measure the indoor performance of the three different rooms with different orientation have, measurement period was from 08-19th of May. The indoor air temperature 10th of May (fig 3.1.2.1) was closely examined, during the time of the measurement the temperatures in room one and five followed each other closely, and this was due to the occupants having a coffee ceremony and machinery usage. Room one and five has 35 degrees Celsius which is +4 degrees Celsius higher than room three, this is due to the orientation and room three having the patio as a buffer and which achieved 31 degrees celsius. (Continuous 10 days monitoring can be found in Appendix 3)

Figure 3.1.2.2 Ocupant Spatil Indicator At midday with an external air temperature of 22 degrees Celsius room one has a peak from 10 am to 2 pm, room three from 11 am to 1 pm, and room five from 9 am to 3 pm, peaking over 30 degrees Celsius which in result is +3°C over the comfort band.

Courtyard is defined as“an area unroofed that is entirely or partly enclosed by walls or buildings, usually forming part of a large house.”

Ethiopian traditional houses are mostly of courtyard type, it provides a practical, functional, spatial, social culture and, climatic, as a basis for a traditional house type associated Ethiopian way of life. The courtyard is a collective buffer between the private and the public domain. The primary purpose is for cooking, washing, playing, place to keep the animals, gardening, and for open fires during traditional festivities. The traditional architectural forms and spatial design elements contributed to determining the climatic environment, also presents that the courtyard is a place to manage the social needs of the occupiers. The spatial occupancy indicator (see fig 3.1.2.2), shows the network between the different rooms and how the movement of these individual families is mapped out (room one 16.7m2, room two 17.1m2, room three 15.8m2, room four 19.6m2 and room five 15.3m2) and the relationship between the patio, rooms and the garden.

Figure 3.1.2.1 Selected Day from Data logger monitoring

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All 15 living residents conducted a questionnaire in order to compare occupant’s responses mostly regarding thermal comfort and space functionality/requirement. Surveyed parameters include daylight availability, thermal comfort, ventilation, noise, the temperature in the dry and rainy season and space requirement. The outcomes of the occupant surveys (see fig 3.1.2.3), indicate room three and five have an unsatisfactory response to the temperature in the dry season, while the others rooms were neutral in both seasons, while thermal comfort scored satisfactory across all the rooms. In terms of ventilation and noise in the rooms, the responses are distributed across the chart and were in the range of unsatisfied and extremely satisfied. Considering the lack of space for the occupants, they answered neutral and satisfied with the space functionality and size.

The daylight distribution of the vernacular house is predicted to have a poor outcome, as highlighted on the spot measurements from the fieldwork (fig 3.1.2.4). The useful daylight illuminance (UDI) of room one, three and five was measured, simulation studies read room one 31% of the time is in the range of 300-500 lux, room three 33% of the time and five 40% of the time is in the range of 300500 lux threshold. It is predicted that room three would achieve less than room one due to obstruction of patio and roof and, which could indicate self-shading on room one. Mapping the indoor distribution of UDI, more than a range of 2000 lux, room one and five obtain a 12-13% illumination level, while room three receives 0% above 2000 lux threshold. As the units have the right to light, it is evident that some of the room illuminations achieve mediocre results.

Figure 3.1.2.4 Usefuul Daylight illuminance

Figure 3.1.2.3 Occupant Survey

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3.2 Vernacular Studies ‘Chika-Bet’ ‘Vernacular from the word vernaculus, meaning Native = vernacular architecture - native science of building.’

Representation of space in the context of vernacular architecture begins with a single cell shelter, and this is architecture referring to the informal building structures through traditional methods of building by locals, which also varies with the material from one context to another and is the most common method of a building (see fig 3.1.2). (Noble, 2007 p.82) states “Traditional structures normally reflects their surroundings”. ‘Chika-bet’ traditionally made by non-architect is a vernacular housing typology, this mud-based construction dwelling fundamentally incorporates a mixture of mud (sand/clay), water and straw, which then rendered onto a eucalyptus tree frame also used as the structure of the dwelling. It is first erected with wooden structural timber frame and poles with the right length put into the soil, which then is plastered with the mixture of Chika. Timber poles sometimes made out of termite resistant woods like Thid (Juniperus Procera Hochst) or Kosso (Hagenia Abyssinica) are put into the soil with a regulated distance to use as spacing, Kosso and this has traditionally been used to obtain durable structures in the dwellings. Bekele et al (1997).

Figure 3.1.1 Vernacular Construction Dwellings constructed by mud and wood are extremely sensitive to climate change and therefore assumed that it could not resist change-induced impacts like heavy rainfall compared to concrete building homes.

The framework is later on covered with mud mixed with straw. Due to rapid deforestation with resource depletion, the termite-resistant species mentioned above have become rare and expensive and has been replaced with Eucalyptus. “The timber-species mainly used, at least in the highlands, has been and still is fast growing Eucalyptus.

However, in order to enhance the durability of the walls, with regard to general decay and/or termite attack, some poles of more durable timber species” (Hjort & Sendabo, 2011). Living model wall of the vernacular house was created using, eucalyptus tree for structure, laterite clay soil from the highlands combined with straw for density, and the holes provide better hold for the plaster to sit in the mud (see fig 3.1.1). The work of a mud house reflects the rich diversity of locally available materials, Addis Ababa’s climate, and the intricate variation in social custom and artisans.

Mudhouse, the adobe technique provides an affordable and sustainable construction material with low environmental impact compared to concrete. As the population density is growing and the high rate of poverty, the traditional solution combined with a contemporary outlook can be suitable for constructing affordable dwellings and prevent inadequate living conditions as well as reducing the carbon impact. An unfired clay as used in this case study, has bestowed to provide passive environmental control in buildings through buffering of air temperature and relative humidity (RH), during times of low humidity, it will release the stored moisture back into the air, which contains the internal humidity inside in a range of 40-60% RH.

Around the city, there are different traditional styled house types which include, bamboo, plastic, corrugated iron sheets (CIS), concrete/cement, thatch, wood and mud, asbestos, and so on. The households in Kirkos, Arada and Addis Ketema sub-cities have the highest use of mud and wood as a construction material for their homes, where also the highest need for repairs is apparent, compared to the Bole sub-city, wheres the primary construction material used is concrete, (larsen et al., 2019). Hence a study of this type of vernacular architecture is conducted.

First built in ca 1960s, proper roof and patio design provided

Extention 8 years later (L-shape), ca 1968s, lacks quality.

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20 years later, extra space built, for ‘compact living’

Figure 3.1.2 The Evolution of the ‘Chika-bet’

3.3 Thermal comfort The inputs of the construction parameters for the mudhouse on TAS (thermal modelling software) is an accurate u-values for the construction components that was set to allow more thermal assessment of traditional building elements. As follows: the external and internal wall thickness 180mm, from inside to outside (Plaster 10mm, Soil 60mm, Wood 15mm, Soil 60mm and Cement rendering 15mm as a finish), a total U-Value of 1.4W/m²K. The straw was not excerpted as an input, due to non-existing properties of the ‘Chika’ straw when calculating on the thermal software. Straw is known to increase toughness in the material, and as combined with mud, it creates rigidness and roughness on the surface generating micro levels of self-shading on the drywall.

Table 3.1 Internal conditions of mud house construction

The existing glazing has single glazing with a solar transmittance of 0.7 and emissivity (external and internal) 0.845, with an aperture opening in summer was facture as 50% and monsoon 40%, the conditions of the different parameters were input on TAS (see table 3.1 and 3.2 for Internal conditions). Regarding the roofing construction, it is made up by a 10 mm lightweight plaster (asbestos) followed by 20mm wood structure made of eucalyptus tree and 15mm corrugated steel roof (CSR) on the outside, which was the original design of steel/iron profiled roofing sheet, it has a total of 2.37W/m²K in U-value and R-value of 0.422Km²/w thermal resistance.

Table 3.2 Internal conditions of concrete construction

1

3 5

Figure 3.3.1.1 Thermal Modeling

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3.3.1 Frequency Analysis For the free-running calculation, a comfort lower limit on 18-degree Celsius, comfort upper limit 27-degree Celsius and overheating higher than 28-degree Celsius was an input for the comfort band according to Fergus Nicol graph formula. Three rooms out of the five rooms were studied, room three, which is south facing and has a patio as a buffer. Room one west facing and five north-facing are both directly exposed to the outdoor courtyard and no buffer.

The thermal performance of the mud technology was examined to understand the comfort levels each of the rooms of the study had. A concrete solution was also tested to see if the thermal performance changed with that type of construction. Reason being, concrete is highly used, and mud is disappearing as traditional construction methods in the urban area. The input on the internal conditions was slightly different as the U-value on the concrete construction is 1.33W/m²K and the infiltration rate is set on 0.3, whereas mud technology a U-value of 1.4W/m²K is set and the infiltration rate on 0.7, main reason being an old built and has typical thermal bridges, resulting high infiltration through tiny gaps between wall, glazing and window frame. (see fig 3.3.1.2)

Room one is west facing and directed to the courtyard is within the comfort 80 per cent of the time yearly, while room three is facing south orientation and is 84 per cent within the comfort and 16 per cent below comfort, this is due to the patio acting as a buffer. Room five is north facing orientation has the same two per cent lower comfort and two per cent higher on the below the comfort compared to room three. (fig 3.3.1.3). The patio receives 20 per cent higher within comfort, and only 4 per cent below comfort with the mud technology compared a test with concrete that achieved 50 per cent below comfort most of the time (fig 3.3.1.4).

Figure 3.3.1.3 Free running - Basecase Mud construction

Figure 3.3.1.2 Infiltration Through Building Fabric CIS corrugated iron sheet Lightweight plaster Mud & straw mixtrure

Reinforced bond beam Lightweight plaster Concrete block work

Cement rendering

Figure 3.3.1.5 Construction methods

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Figure 3.3.1.4 Free running - Scenario 1 Concrete construction

3.3.2 Daily profiles of representative days Meanwhile, the concrete is 2 degrees Celsius higher in the morning and 1-2 degrees Celcius lower in the evening.

Room three and five have the same temperature conditions throughout the day. In the morning up to midday the concrete construction is 1-2 degrees Celsius above the mud, and in the afternoon the concrete construction is 1-2 degree celsius below.

Three days was chosen as a typical day, for short rain season January 16th day 16, dry season May 16th day 136 and long rain season August 16th day 226, analysing room one, three and five (see fig 3.3.1.1). On January 16th the mud technology was slightly below the comfort band in the morning (fig 3.3.2.1) in room one from 9-10am, room three 7-9am and room five from 6-10am. May 16th in room one the mud air temperature is six hours lower in the morning (fig 3.3.2.2) and three hours higher in the evening, therefore being one hour outside the comfort limit compared to the concrete construction. Room five indicated that the concrete method drops 1-2 degree celsius then the mud, while room three both construction methods are uniform throughout the day. The graft for August 16th (fig 3.3.2.3) shows the mud construction in room one is slightly below the comfort band one hour in the morning.

Figure 3.3.2.1 January day 16

Figure 3.3.2.2 May day 136

Figure 3.3.2.3 August day 226

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3.4 Design Application 3.4.3 Research outcome

What climatic response does the vernacular design respond to, what are the advantages and limitations?

The intention of testing mud and concrete construction types was conducted for the understanding of the different abilities to achieve comfort, even though the infiltration rate and U-value was not an identical input. The mud technology thermal mass has an excellent capacity to store and emit heat, as it has a higher heat capacity and moderate conductivity than concrete, which indicates it slows the rate at which the temperature within the construction changes. The fenestration design and glazing choice have an impact on thermal comfort and solar heat gains. As well the tremendous internal heat gains from the appliances used in the rooms, leading to an increase of the indoor air temperature. As observed from the field study, the rooms were often dark, achieving only diffused daylight; this was sufficient enough for the occupiers. As the occupants do not utilise the windows and only use the doors to ventilate, a change of disposition and renewing the set would be required to maintain thermally comfortable conditions in the dry season.

3.4.1 Positive attributes//Advantage The main building on site provides excellent shading and ventilation in monsoon and dry seasons. Reason being the porch is used as a barrier between inside and outside, as well as the roof construction technology, protecting the walls from the sun and rain. The ‘Chika bet’ has the effectiveness of thermal mass to moderate indoor air temperature resulting in better comfort as well as the walls has the ability for humidity absorption.

The courtyard is the centring of dwellings and used as a multi-purpose shared area, which provides a practical, functional, spatial, social culture and, climatic, as a basis for a traditional house, connecting to each room and therefore combine the collective with the public domain, (fig 3.4.1).

Cheaper construction material and lower embodied energy than concrete. The rigid material of the dry mud wall acts like self-shading of the finishing against irradiation.

The social ties, neighbourship and sense of community endorsed through sharing of spaces, which is the importance of the social network in Ethiopian society and way of life, (see fig 3.4.2)

How to then improve the parameters of the ‘Chika bet’, as mentioned mud is a low bearing structure, perhaps a modification of the structural system to concrete and an infill material as mud would be a possibility to Improve and balance the conditions of the construction and thermal comfort of the occupants through the use of appropriate building strategies. Careful consideration should be addressed to attain a well balanced indoor temperature and adequate diffused daylight, to then integrating thermal mass, protection from an excessive amount of solar radiation and ventilation strategies on the design stage of this project.

3.4.2 Negative attributes/ /Limitations The predominant use of mud and wattle ‘Chika’ in the construction of housing walls and floors calls for frequent replacements and repairs, which leads to an expensive refurbishment in the long run. Also, the dust from the earth and mud utilised for the construction leads to enhanced susceptibility of the dwellers to respiratory diseases conditions, especially among children. It is also a low bearing structure, which reduces possibilities to go vertical; hence, the majority of households are single story units.

Figure 3.4.2 Socio-Economic network

Figure 3.4.1 Modern Vs Vernacular Courtyard

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CHAPTER 04

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CHAPTER 04 Social Integration of Living Conditions 4.1 Housing Crisis

Overcoming the housing problem is vital, due to rapid growth in the past decade and the city’s expansion are affecting the social and economical in the built environment. The fact that the city is getting more congested, the need to build vertical has implemented meaning building high-rise concentrating urban functions on the same square miles or kilometres. Especially in zone one and zone two of the central business district (CBD) and commercial districts of the city are increasingly going vertical, hence it requires diligence in three main areas: institutional structure; housing supply and demand. UN.Habitat (2008)

Kirkos the study district has the second-highest overcrowding, only 71-85 per cent of households has sufficient living area which roughly estimated three people per living room. (see fig 4.1.1). According to United Nations Human Settlements Programme goal 11 for the 2030 Agenda, states that “a house is considered to provide a sufficient living area for the household members if not more than two people share the same room.” UN HABITAT (2018)

Responding to the housing challenge in the urban areas are characterized by the coexistence of informal and formal settlements (Table 4.1.3). Since lack of houses and the increase of slum areas is the main reason, the housing schemes were put in place as increase takes place principally in informal and slum settlements where access to services and infrastructure are inadequate or nonexistent. Majority of the housing in Kirkos are government-owned housing (fig 4.1.2) the white on the map shows all the informal settlements that are not surveyed and registered by the kebele.

Is the government of Addis Ababa building to build and expand without any consideration of the environment, economic and social factors, and displacing citizens due to reconstruction, development and high growth in population. Even though theoretically the government owns the land and seizing it from individuals has left a tear in the social framework. People now travel longer between their home and workplace because most of the residential areas are situated on the outskirts of the surrounding sub-cities and business remains concentrated in the central sub-cities.

What are the living conditions in Addis Ababa?

The vast majority of Ethiopians suffers from a shortage of housing but mainly from poor quality homes, dilapidated and cramped houses which lack even the necessary facilities, such as toilets, roughly 24% have no form of toilet and 63% use shared. Only 20% of the current housing stock in the city is in a fair condition, whereby 60% of Addis’ inner-city houses need a complete replacement, 39% of the population is living below the poverty line. Massive and rapid urbanization increasingly demands more water, energy, food, land and housing, causing rapid land cover change and alterations in biogeochemical cycles and hydro systems, loss of biodiversity and soil degradation.

“The demand for housing during the planning period is forecasted, taking into account six important variables, namely the existing stock, population growth, backlog, dilapidation, overcrowding, conversion and contingency.” NATIONS, U. (2017)

Figure 4.1.1 Overcrowding in Addis Ababa

Table 4.1.3 Estimated housing needs for 2023 Figure 4.1.2 Addis Ababa suveryed district housing

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4.2 The governmental Housing schemes

Scale 0.3 -2006-2010 Integrated Housing Development Programme (IHDP) Phase one, is based on already tested and implemented housing typologies in the city from 1999, which the government declared to design. The program involves a combination of government financing and construction of housing in large and medium-sized cities, targeting mostly at middle and low-income households. Simultaneously this program marked the end of the low-cost housing (LCH) schemes. Incorporating the construction efforts within the former AAGHP, the IHDP set ambitious five-year goals for the period for 2004-2008 mainly targeting the capital city. Apart from the reduction of slums dwelling by 80%, the program also planned to build 150,000 to 200,000 housing units, creating 60,000 new jobs. NATIONS, U. (2017)

The housing sector has been challenged for over a century and continues to be challenged, the capital being incapable of providing enough and adequate housing, especially for low-income citizens. In early 2000, the city’s 4 million inhabitants persisted toward an accumulated housing backlog a total of 233’000 units. A growing vertical stem of affordable housing was promoted then by the Ethiopian government, where the schemes have created a vast amount of housing units unseen in the country’s history.

Over the years, the city has needed to up their housing development scheme, and the housing plan divides into three main progressive stages of the program implementation: (Tipple and Yitbarek Alemayehu, 2014)

In 2006 since launching the housing association’ integrated and housing development plan’ the government has built condominium estates in a very high phase. More than 250 000 subsided flats have been transferred to their new owners and continue to do so, and the condominium program is financed entirely by the public resources. (Tipple and Yitbarek Alemayehu, 2014). IHDP key element for overall poverty reduction and urban development objectives are to generate more job opportunities, provide adequate shelter and empower local businesses. This scheme provides a more significant achievement for the whole society, seeking comprehensive poverty reduction. It also ‘enable low-income’ resident to become house owners and thereby ensures a fair distribution of income.

Scale 0.1 - 1999- 2002 low-cost housing scheme (LCH) the low-cost housing main aim is to decrease costs and enhance efficiency consisted of planning new and more affordable units. From the year 2000, the city had gathered a residence backlog of 233,000 units and would need for additional 223,000 housing units by 2010. So for the first time in history, a full scale and operational low-cost housing program were developed.

Scale 0.2 - 2002-2006 Addis Ababa grand housing program (AAGHP). Due to change in national development policies, between 2002-2005 the Ethiopian people’s revolutionary democratic front (EPRDF), which is the government introduced the Sustainable development and poverty reduction program (SDPRP), which declared the need of formulating housing policies that would improve housing affordability via introducing appropriate housing standards that consider local resource capacities and requirements. In 2004 Gerji, the first condominium site was built following LCH technology to build four to five stories featured by four newly designed prototypes.

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Figure 4.2.1 Proportion of non-slum and slum areas

From the different stages of the scheme, the price for the cost of construction has increased from the low-cost housing scheme to the Integrated Housing Development Programme, it doubled in the price:

IHDP Phase two - improved from phase one by setting up five new goals: Goal 1: Increase the housing stock in the city with a particular focus on affordable housing (see table 0.4 distribution of households by income group)

Scale 0.1 cost of construction was ETB 500-800 (£14-22) per square meter

Goal 2: Improve the quality of the housing stock and the living environment in residential neighbourhoods

Scale 0.2 cost of construction was ETB 800-900 (£22-25) per square meter

Goal 3: Ensure balanced social and land/building use mix

Scale 0.3 cost of construction was ETB 1507 (£42) per square meter in 2009/2010.

Goal 4: Achieve compact and green development

Linear redevelopment

Inner-city renewal

Land readjustment/sharing

Infill in low-density condominium sites

having a Built-up Ratio (BUR) below 20%:

Despite clearly missing the aspire cost targets and quantities within the given time frame, as of 2010 a respectable amount of 80,000 units had been built all over Addis Ababa, the original target was set at 223,000 by 2010. ( and Martin, 2009)

Goal 5: Guarantee the provision of shelter for the homeless

Religious organizations

Woreda administrative offices to mobilize

resources for the construction of social housing

Integrated Housing Development Programme is the second phase of the ambitious Integrated Housing Development Programme (IHDP Phase1) that between 2006 and 2010, (table 4.2.1) and with the target of building 400,000 homes, aimed not only to reduce the shortage of houses and create jobs but also to encourage a saving culture and reduce by 2020 slum areas by half (fig.4.2.1).

Table 4.2.1 Distribution of households by income group

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4.3 The Condominium Housing program

No investment developers are associated with the scheme, meaning, no uncontrolled capital gains going to private hands. The Addis Ababa Saving Housing Development Enterprise (AASHDE) are entirely accountable for administering the condo-units, utilizing a computer-based lottery system which assigns to their owners. The Integrated Housing Development Programme has established two methods to address the social as well as spatial conceptual pillars: pillars: individual home-ownership through a mortgage system, and highly standardized housing block typologies. The Addis Ababa Housing Development & Administration Agency (AAHDAA) who administers the 10/90 and 20/80 condominiums.

The driving factor of the condominium housing program in Addis Ababa is densification, which wholly is funded by the public resources and without the aid of external international investors and donors. As the vast majority of Addis Ababa is built up of informal housing, In 2006, informal housing was primarily clustered in the central business district (CBD) of the sub-cities. Addressing to Kirkos, which is one of the main sub-cities with many informal settlements (see fig 4.3.1).

Yeshitela describes, of the entire area of residence in 2006, where informal housing included 57% of low-rise and mixed development above four floors comprised 37 per cent, single-family housing included 5% and condominium units four floors and greater comprised only 1%.

(Yeshitela et al., 2019). Of the total area of housing in 2016, informal housing declined to 38%, low-rise and mixed development above four floors declined to 26%.

Concerning informal homes, the residential area a total reduction of 20 per cent has occurred from 58% to 38%.

The establishment of housing units has improved significantly between 2006 and 2016, as the majority of the city’s housing supply has reduced and shifted from informal to formal settlements over the decade, and the densification process of condominium housing is more significant after the schemes were introduced. (Delz, 2019)

The 10/90 condominiums scheme (fig 4.3.2) consist of low-rise buildings, is a single-story unit which can be increased up to two floors. Usually, this house type is a studio style, and a target group are a low-income group.

20/80 condominiums mid-rise buildings with ground floor plus four to ten floors, this house type targets mostly for one, two and three-bed units with a 10% commercial space, PPO (2017). The Addis Ababa Savings & Houses Development Enterprise (AASHDE) which constructs the 40/60 condominiums scheme consist of high-rise buildings ground floor plus 12 floors, similar to the mid-rise this scheme is also targeted for one, two and three-bedroom units, but with a 20% commercial space.

10/90

20/80

Figure 4.3.1 Informal Vs Formal Condominium Housing

40/60

Figure 4.3.2 Condominium Scheme

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Across the three housing schemes, one million people listed, which response to the housing challenge of rapid urbanization, by creating affordable units that are lowcost housing typologies.

Since the development of the scheme, 211,000 condominium units have been successfully transferred to their beneficiaries, and the number of a new high rise in each sub-cities can be identified on the diagram (see fig 4.3.3) — furthermore, the locations of high-rise and condominium buildings in the cities project plan. In terms of construction of high rise buildings, central sub-cities have a significantly higher density of high rise. Kirkos is one of the three sub-cities that experience the highest amount of mid and high-rise construction since 2010. (Delz, 2019) Figure 4.3.1.1 High-Rise Buildings

4.3.1 Vertical Living Given the gravity of the situation, the tendency to opt for a quick-fix approach to address the housing crisis has become a more manageable approach for the government.

The “urban renewal” concept involves massive-scale demolition of existing areas, forcing the re-housing of inhabitants into medium and high-rise condominiums, as a means to achieve densification to make more land available for private investment.

As Mayor of Addis Ababa stated on the fortune: “Old houses will be demolished, and new houses will be built in selected pockets to embellish the appearance of the city.

They will be replaced by apartments of three and four storeys that could fit the status of Addis Ababa.” (Addis Ababa, Ethiopia, July 18, 2004).

With this type of development for condominium units, the government aims to provide shelter to the low-income residents of the city but also help generate employment to the tens of thousands of young people of the city. ( and Martin, 2009). Addis Ababa can quickly identify as a ‘concrete jungle’ (see fig 4.3.1.1 high rise buildings), the past decade the excessive use of concrete as a building material is becoming more significant than ever, particularly the release of high carbon emissions into the atmosphere which is contributing to greenhouse gasses. Pricing strategies becomes vital to increase affordability for low-income households since studio and one-bedroom units are sold lower than their construction costs, while two and three-bedroom units sell higher than the units construction cost. As the cost of building materials accounts for the most significant proportion of the overall construction cost, hence innovating low-cost building material that is adaptable site construction will be vital.

Figure 4.3.3 Densification of Sub-cities How can a scheme be feasible and advance itself as a resilient standardised method? Furthermore, considering the different socio-spatial layers, that characterise the fabric of Kirkos, which is also accounted for a mid-rise project that can strike the same density of the Condominium housing, by ensuring a social transformation following the valued traditions and norms of the society, as well as the economic development and urban way of life in a city. An Implementation of a design guideline for the establishment for formal settlements respecting the traditional way of living and social network will be further examined.

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CHAPTER 05

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CHAPTER 05 Analytical Work 5.1 Methodology for design Kirkos district areas characterised by the coexistence of formal and informal settlements; therefore this objective implies to establish design guidelines toward the upgrading of an informal neighbourhood by responding to the changes to the context Kirkos sub-city, respecting the social networks and the traditional way of living of the inhabitants.

Utilising quantitative instruments such as TAS, Rhino and Grasshopper for numerous simulations, to conducted a comfort analyses as it is a critical element in consideration of the design process to understand the performance of the chosen building design.

The primary quality the condominium scheme lacks from the study of vernacular examples are the affordability due to construction cost and the multi-purpose shared area that the single-story units, that provides the residents a functional, spatial and social culture area which is the social setting that the neighbours have more accessible way to connect with each other as a collective domain, which is one of the spatial requirements for the design process that is taken into consideration.

The living requirements for the design process comprehend to combine two main areas of adaptability and sustainability to achieve good habitable densification on the plot that responds to the climate as well as occupancy function, (Hailemariam 1994). Furthermore, to use sustainable design to achieve thermal comfort, considering energy efficiency, productivity and well being for the occupiers.

Site

Form & Building shapes

Site planning Orientation Size & position

Courtyard & Communal space

Ventilation, Daylight & Shading

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Indoor Temperature balance: careful use of materials for improved indoor conditions.settlement patterns &

5.2 Defining Design principles Massing A: is an L shaped building form that is following the existing footprint and building against party walls due to neighbouring residents. The total built-up area on this massing is 887m2 and a total courtyard area of 202m2 with a 10% for commercial area 98.5m2, accumulating in a total of 17 units.

As the majority of the site consists of a single-story household, respecting building height complies by the maximum height of the surrounding area, a five-story condominium residential block north of the site. The orientation of the massing was following the same form of the existing building, due to limitation and respecting the urban layout of the site, especially the orientation east, west and south which has adjacent neighbouring residential housing and north of the site is the only road which has accessibility. The proposed outcome design is going against all the principles of environmental design by constructing setbacks on the proposal, as shading is the key for this project. If more flexibility were optional openings would have faced differently, as is not ideal due to the high sun angle it is easier to shade south and north, but massing design is mainly facing west and east which have the units and most exposed. Building heights and regulation was defined from EBCS(1991) and PPO (2017).

Massing B: is a U shape, an addition to the L-shape was made to add more density to the plot. Achieving a total built-up area of 1238m2, and courtyard space of 120m2 which is 82m2 less than massing A, as well as 396m2 a built-up area. 10% for commercial space 137m2, giving a total of 24 units adding seven more units than the L shape solution.

Massing C: is a C shape addition, that has been pushed back by half on the east side of the tower to maximise west aspect. With a built-up area of 1049m2, and a total courtyard space of 166m2. A 10% commercial area of 116m2, accumulating a total of 20 units to provide more quality by creating a medium exposure compared to massing suggestion A and B, creating a combination of density and communal space. (See fig 5.2.1.1)

5.2.1 Massing strategies The massing stage carries out three different suggestions that will be tested, for a mid-rise with a ground floor plus five floors on a total plot area is 405m2, which compares and analysed against density and sufficient enough communal reservation, the ‘courtyard’. (see table 5.2.1.1 Midrise massing outcome).

Figure 5.2.1.1 Massing Stages

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To define the impact of horizontal radiation with different design forms a study of the different seasons following the monsoon and dry season of January 10, May 10 and August 10 and critical hours from 8 am to 4 pm was measured in the courtyard (see fig 5.2.1.2) Massing A, results in a value between 180-600 wh/m2, massing B, between 60-200wh/m2 and massing C, 120320wh/m2. The massing was defined by the block size as well as the impact of irradiation, it is evident that massing C, achieves a balance between massing scenario A and B and therefore it the chosen proposed design.

Table 5.2.1.1 Mid-rise massing outcome

Figure 5.2.1.2 Hourly average horizontal radiation

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5.3 Program Distribution & Design criteria The main target is mid and low-income groups providing a total of six floors (including the ground floor) housing typology. The IHDP scheme recommends a walk-up building (no mechanical lift) for G+4 and G+5 housing,to minimise the cost associated with maintenance and construction. Following the government guidelines of the housing scheme criteria of Addis Ababa planning commission and city administration, the same typology demands were an input (see table 5.3.1) Four different typologies unit was considered for this design (studio, one bed, two beds and three beds) to best target different individuals. Due to cramped conditions of informal settlements and Keble owned housing, each unit service area must be provided/contained with a kitchen and bathroom.

(Rollnik, French and Daltrop, 2010) Majority of the housing design must contain one bed (40%), the reason being cost and floor are for a one-bedroom unit is prevalent and economical amongst the applicants for the condominiums (see fig 5.3.1). A total of 10% of the program is designated to commercial purpose, in principally it accommodates space for small shops or other small scale businesses located on the ground floor for permeable access and separating the private with the public. According to the regulation, these spaces are 100% sold and not rented.

Figure 5.3.1 Programmatic AXO

Table 5.3.1 Unit typologies

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5.4 Passive Design Stratesgies 5.4.1 Outdoor strudies// Courtyard

Therefore the design focuses mostly on solar design and solar protection, as the horizontal surface is the most critical in this climate, hence comparing it to solar radiation on the facade the roof receives three to five times more irradiation due to being close to the equator, a proper roof design as an element it is particularly vital. Moreover, it can resolve the issue of orientation; therefore, there are proposed two different width techniques of 1.5 meter and 3 meters from the facade (see fig 5.4.2.2). Providing adequate shading strategy (fig 5.4.2.2) from the horizontal radiation is vital, due to the solar angles and amount of radiation falling onto the surface of the courtyard causing heat stress in some seasons (UTCI simulation from chapter 03). The issue is mitigated with a roof design, structure of the corridors and vegetative covers to prevent reflected radiation, making the courtyard more comfortable as well as protecting the units.

Following the vernacular case study, the importance of open sky courtyard is a prime space for the dwellings due to its traditional use of the space. Where day to day activities are performed e.i cooking, cleaning, gathering where villages related issues are discussed, or ceremony celebrated; hence, the communal areas for the inhabitants are responding to the culture demand. (Rollnik, French and Daltrop, 2010). The function of the space provides a communal indoor area on the ground floor as well as an outdoor open courtyard. A protected space for residents to perform traditional tasks, which can be utilised in all weather conditions “Optimal cooling occurs where the building surrounding the courtyard is one, or even three, stories high. The small courtyard acts as a ventilation shaft, permitting hot air to be expelled as it is warmed by the sun during the day, and allow cooler night air to sink and pass into surrounding rooms after dark� (Noble 2007 p228)

5.4.2 Facade Design The dynamic of the sun position seven months out of the year indicates the need for sun protection in the courtyard (fig. 5.4.2.1). From April to August the east of the courtyard will receive sunlight from 07 am to 11 am a total of five hours, whilst from March to October the middle of the courtyard receive sunlight from 11 am to 1.30 pm a total of three and a half hours, the most critical months being March, April and May which requires shading in the afternoon hours . Allowing the courtyard to receive the peak and the highest values of instant solar radiation in certain hours.

Figure 5.4.2.2 Roof Design

Figure 5.4.2.1 Sunlight study courtyard

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1.5M

3M

Figure 5.4.3.2 Hourly average Horizontal radiation, roof 1.5M and 3M 5.4.3 Roof Design The passive design strategies ought to highlight the environmental performance and its thermal characteristics of the building. The prevailing wind is reaching from east to west; thus, the vernacular ventilation system allows to cool down the corridors and parts of the courtyard, it provides natural cross ventilation throughout all the units with a potential to ensure good air-quality and thermally comfortable healthy living environment. (see fig 5.4.3.4) The facade design was driven by the roof design, (fig 5.4.3.3) as it is the primary obstruction to daylight, the aim is to get diffuse daylight into the units rather than direct. Rammed earth has the potential of high thermal mass and capacity to moderate the indoor environmental conditions (Hyde, 2008). Through the construction frame, it will allow natural absorbing, cooling and heating storage to improve the living conditions of the inhabitants. Greenspace is introduced to provide better air quality in the courtyard, corridors and roof also,to provide shelter in different conditions, as well to moderate Addis Ababas existence of intensified Urban Heat Island (UHI) effects.

Figure 5.4.3.3 Roof construction

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WEST

EAST

Green space Roof garden

cross ventialtion ’

Thermal massRammed Earth

Single sided ventialtion

Prevailing wind East Average 2.3 m/s

Green space courtyard

Figure 5.4.3.4 Bioclimatic Section

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Vernacular ventilation opening - courtyard & corridors

5.5 Environmental advantages of Rammed Earth “Rammed earth; a construction method made by compressing or binding earth�

Earth is the most refined and natural construction material, and thereby the oldest. This ancient earthen constructions technique uses raw materials from the earth as gravel, sand, silt and clay (see fig 5.5.1 Construction process of rammed earth). It is sustainable, natural and most inexpensive building methods has appealed to many sustainable buildings around the world in a range of environment regions with conditions from hot, wet to dry climate. The construction of partitions and floors offers a simple, robust construction solution, thermally durable and non-combustible material. The negative attribute of rammed earth is susceptibleness to water damage, if not adequately protected and sustained from the heavy rain season of Addis Ababa.

Figure 5.5.1.1 Construction Process

How does the structure respond to context?

Condominium blocks have high construction cost 3800 ETB per square meter as some units sold higher than their construction cost; this is one method the scheme is achieving more affordable units. The concrete solution with a structure and envelope of concrete blocks of this design will cost 3700 ETB per square meter. The positive outcome allows for sufficient lateral and vertical load and flexible design. The rammed earth solution has a lower price, 2300 ETB per square meter, the structure and envelope of rammed earth will allow for dynamic lateral and vertical load, a flexible design where local codes are available. The envelope has a high thermal capacity, flexible opening for daylight and lowers embodied energy.

With its material coming directly from the local area allowing the construction of the earthen wall blending into its surroundings that follows specific structures and layers in the landscape. The use of local material with the consideration of local climatic conditions as well as for its easy construction and replicability leads to an excellent holistic design approach.

5.5.1 Rammed Earth Construction Raw natural materials have proven to reduce the cost of wall construction compared with the conventional building materials. The cost of construction supplies accounts for the most significant proportion of the overall construction cost in Addis Ababa, innovating low-cost building material is vital for low-income groups. (fig. 5.5.1.1) Condominium Blocks

Concrete Solution

Rammed Earth Solution

Figure 5.5.1.1 Project Feasibility & Cost comparison

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5.6 INDOOR studies Regulations from other countries with hot climate, are used as references for guidelines, as the climatic conditions of the city are not sufficiently considered by the Ethiopian building directives or in the Council of Ministers Building regulation, where there are no provisions for thermal comfort, water and energy consumption of buildings.

East and west facade exposed to high direct solar irradiation; therefore, the need for facade treatment from solar protection is crucial for this climate. (see fig 5.6.1) The solar studies indicate that the east facade is exposed three-meters inside from the facade, therefore needs protection from 07 am to 09 am all year round. On the south facade the exposure reaches two-meter inside from the facade, therefore in January from 10 am to 1 pm, and November to December at 10 am needs solar protection. The west facade shows needing protection eight meters inside from the facade from 2 pm to 5 pm in January and May. North facade is exposed seven meters to the inside from the facade from 2 pm to 4 pm in May to August

5.6.1 Window Configuration// Design Window configuration and shading design follow the of the Ethiopian building code of standards (EBCS), a regulation that dates back to the 1980s. The recommendation states that 1/6 fraction of the floor area should be glazing to provide sufficient daylight, with non-reflective glass. As well as a two defined set back, A: if there is a window for viewing, this must be two meters away from the boundary of the site e.i bedrooms, kitchen and living room of the neighbour. B: If there is a window for ventilation, this must be 1.5 meters away from the boundary of the site. The 1/6 fraction of the units is as follows: studio 30m2 = 5m2, 1 bed 50m2 = 8.4m2, 2 bed 75m2 =12.5m2 and 3 bed 100m2 = 16.6m2.

Figure 5.6.1.1 Window Configuration

Figure 5.6.1 Sunlight studies on facade

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5.6.2 Natural Daylight and ventilation

Typically solar radiation is penetrated through the east and west facade, achieving a peak absorption on the windows, hence there is a need for facade optimization for control and protection against heat gain and high solar irradiation on the facade, the windows are recesses back and angled depending which floor. Base case scenario presented have windows which are not recessed, and no shading elements rendered (see fig 5.6.1.1), For the lower floors (ground floor to the first floor) needs more exposure; therefore, it is angled 0.20 meter and 34 degrees outwards. The middle floor (second to the fourth floor) needs medium exposure, thereby angled 0.10 meter and 18 degree inwards. The top floors (fifth and sixth floor) needs limited exposure; therefore, it is angled 0.20m and 18 degree inwards.

Hourly average radiation from 8 am to 4 pm was analysed in the three-seasons, the months of January, May and August (see fig‌ Facade optimisation for solar control).

On the west facade the fenestrations received throughout May and August a value between 35- 70 w/hm2 with the peak being in January with 70 to 140 w/hm2. The north in January reaches a value of 0-35 w/hm2 on the ground floor and inner parts of fenestrations facing the courtyard, while north-west and northeast obtain 35 to 70 w/hm2. May is similar to January, and the ground floor attains a value of 35 w/hm2, northeast receives 70 to 140 w/hm2 while north-west obtains 175 w/hm2. August is very much similar to May except the inner west parts facing the courtyard reach a value from 70 to 105 in May to 70 and 175 w/hm2 in August. The south and east fenestration reach a value between 175 to 210 w/hm2 in January, achieving the peaks of all seasons and facades. May and August attain mostly a value between 70 to 105 w/hm2, except the exterior fenestration on the south-east corner which gains the value of 175 w/hm2 in August.

East and west-facing windows will experience maximum solar heat gains in the mornings and afternoons, also south is exposed to direct radiation during the afternoon and will need protection. Therefore the treatment design on the east, west and south facade presents 1/6 opening a substantial element to the indoor but minimal fenestration to allow diffuse daylight and ventilation, allowing to provide adequate shading through the external wall.

West

North

Figure 5.6.1.2 Facade optimasation for solar control

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South & East

A scenario with no roof and shading was also tested to see the different capacities each strategy presented, (fig 5.6.1.2). North achieved a value between 105 to 210 w/ hm2, east reached between 210 to 315 w/hm2, south obtained a number between 105 to 350 w/hm2, and west has reached a value of 175 to 280 w/hm2. On average the strategies of the roof design and window configuration has reduced radiation values between 140 to 75 w/hm2 on the west facade, 105 w/hm2 on the north and a value between 105 to 175 w/hm2 on south and east facade.

Hence its evident the strategies are sufficient against high irradiation on the facade.

the one-bedroom unit on south-west receives illumination level of 14%, while the two-bedroom unit on the north-west attains an illumination level of 28%. The condition was tested with more than 2000 lux threshold to understand how often there is direct sun. Which indicates the studio on north-east obtain a 10% illumination level above 2000 lux, the one-bedroom unit on south-west receives 6% illumination level above 2000 lux, and the two-bedroom unit on the north-west archives an illumination 11% above 200 lux. As the units have the right to light, it is evident the indoor space illumination provides sufficient diffused light, as well as a clear sightline to the sky as there is no obstruction on site.

Mapping the indoor distribution of useful daylight illuminance (UDI) on the ground floor, second and fifth floor, taking the second floor as a medium the simulation studies suggest the studio on north-east has 70% of the time under illumination less than 300 lux threshold, the one-bedroom unit on south-west has 86% under illumination less than 300 lux, while the two-bedroom unit on the north-west is 72% under illumination less than 300 lux threshold (fig 5.6.2.1). see appendix 5 for groundfloor and topfloor UDI. In the range between 300 to 500 lux threshold, the studio on north-east receives an illumination level of 30% in the space,

The typical Floor plan for the units shows how the layout depending on the proposed functions are distributed (see fig 5.6.2.2). The apartment units are arranged around a courtyard, where the service areas are facing towards the inner courtyard with all indirect access for natural ventilation from the corridors. Though the corridors are easier to shade, the design introduces less fenestration, due to cultural reason for a visual barrier for the private spaces.

Hence the living area and bedroom are facing toward the outside for efficient daylight.

Figure 5.6.2.1 Useful Daylight Illuminance 2nd floor

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N

2 BED STUDIO 1 BED

Circulation Toilets

Figure 5.6.2.2 Plan 1:100 & typical units

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Livingroom Bedroom

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CHAPTER 06

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CHAPTER 06 Thermal Comfort 6.1 Thermal Zoning Thermal zoning for the analysis on the second floor takes into account a two-bed apartment of 75m2 facing northwest, the one-bed apartment of 50m2 facing south-west and a studio apartment of 30m2 facing north-east (fig 6.1.1). The south-east one-bedroom apartment was not taken into consideration due to the similarity outcome of the south-west apartment (see table 6.1.1). The occupancy schedule from the fieldwork and case study was input in the conditions, as an example to follow a pattern of a typical household in Addis Ababa.

Figure 6.1.1 Thermal Modeling & zones Building Envelope and Materials Properties External wall: 300mm - U-value 1.9 w/m2k

R-value: 0.35-0.70 m2k/w

Thermal storage of 1830 (Kj/m2k)

Dry Clay 15% -50mm (substitute for silt))

Sand 50% -150mm

Dense Grave 15% -50mm

Expanded Clay 15% -50mm Internal wall: 200mm - U-value 1.9 w/m2k

Dry Clay 15% -3mm (substitute for silt))

Sand 50% -100mm

Dense Grave 33% -50mm

Expanded Clay 33% -50mm Roof: 1400mm U-value 1.23 w/m2k

R-value: 0.80 m2k/w

Suspended adobe ceiling 200mm

Ring beams concrete

Cavity 150mm

Metal truss

Overhanging CIS metal roofing 15-20mm &

1000mm cover width -75mm depth of each fold

(see figure 5.4.3.3 Roof construction)

Figure 6.1.2 Material properties

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6.2 Frequency Analysis The inputs of the parameters on TAS (Thermal Modelling Software) For the free-running calculation, a comfort lower limit on 18-degree Celsius, comfort upper limit 27-degree Celsius and overheating higher than 28-degree Celsius was an input for the comfort band according to Fergus Nicol graph formula.

The simulation of the base case scenario 1/6 fraction window per the code of standards: the north-east studio is within the comfort 80% of the time yearly and 12% below the comfort. The one-bedroom facing south-west is overheating 8% but within the comfort 82% and 9% below the comfort 9% of the time annually. North-west facing two-bedroom apartment is overheating by 6%, but 86% of the time within the comfort and reaching 8% below the comfort yearly. (fig 6.2.1) The total outcome of the base case has a decent level of comfort, but the shading scenario can reduce the amount of solar gain to promote for more comfort by reduction of overheating.

Figure 6.2.1 Free Running Base case

Scenario two introduces a shading component with the use of the external wall by chamfering edges.(fig 6.2.2).

North-east studio unit has improved the comfort by +18% (from 80% -98) and reduced below comfort by -10%, to only achieve a total of 2%. Meanwhile south-west one bedroom has reduced overheating by -6%, improved the comfort by +9%, up to 91% and reduced below the comfort by a total of -7%. At last the two-bed north-west unit has improved the overheating by -5% and below the comfort by -7% achieving only 1% annually on both and improved the comfort level by +11% from 86% to 97%.

Assessing the frequency results, it is evident through manipulation and configuration of the windows as described (5.6.1 Window Configuration) different treatment depending on orientation achieved better comfort than the base case scenario, further strategies can be carried to observe if the outcome could be improved.

Figure 6.2.2 Free Running Shading scenario

Table 6.1.1 Internal Condition Rammed Earth

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6.1.2 Daily profiles of representative days

May shows a peak value at 1 pm 35 w/m2 and 6 pm 52 w/ m2, a massive reduction was constant throughout the day with shading, generating a value between 3-4 w/m2 with a peak at noon. The same can be said of August, peak at 12 pm and 6 pm with the base case resulting in a value of 44- 46 w/m2, while an improved scenario with the shading gives a value of 4-5 w/m2.

The Daily profiles analysed for follows: short rain season January 16th day 16, dry season May 16th day 136 and long rain season August 16th day 226, were chosen as the representative ways to measure the thermal performance.

All the above-analysed scenario of the indoor conditions allows for the spaces to always be within the comfort band.

With regards to the studio unit facing south-north, the solar gains are a peak at 7 am 1 pm and 4 pm with a value between 39-54 w/m2 with a base case scenario. Receiving 30 w/m2 reduction in midday at 1 pm with the shading technique, also reducing the morning gains by absolut from 54 w/m2 to 3-4 w/m2 (see fig 6.1.2.4). The peak in May is between 7-11 am with a high value of 55-56 w/m2, and the shading device has reduced this between 7-10 w/m2.

August results show a reduction on the solar gain with the base case a peak at 11 am - 2 pm shows a value of 30-46 w/m2, the same time a reduced value can be evident with the shading of 10-12 w/m2.

On January 16th, the temperatures are more or less uniform in the two-bedroom unit (see fig 6.1.2.2). Regarding the solar gain, there is a peak of 24 w/m2 with the base case and an improved scenario of 10 w/m2 with the shading. In the hot month of May (16th), the air temperature on the shading scenario has 2-degree celsius higher from 7 pm to 9 am than the base case scenario. Concerning the solar gains, the peak at 1 pm and 4 pm with the base case has a value of 19-25 w/m2 reduced to 8-14w/m2 with the shading scenario. August 16th shows more or less the same air temperature outcome as January (monsoon season), Solar gains peaks at 12 pm and 6 pm with a value of 21-24 w/m2 with the base case, which is reduced to 4-10w/m2 with shading.

All the typical days of the south-west one-bed units and the south-north studio, with both scenarios the air temperatures in presents as uniform, except there is +1 degree celsius indifference on day 136 with shading. The morning gains on the northeast studio were drastically reduced by 98% all the typical days. Same can be said by the one-bedroom unit, which had the best performance of the shading, having an overall 90% reduction on all the representative days.

The one-bedroom unit facing south-west illustrates (fig 6.1.2.3) high value of instant solar gain of 55-60 w/m2 at 12-3pm, on the base case of January 16th, there is a 90% reduction of 6 w/m2.

Figure 6.1.2.1 Patio/Corridors

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Figure 6.1.2.2 January day 16

Figure 6.1.2.3 May day 136

Figure 6.1.2.4 August day 226

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CONCLUSION

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CONCLUSION Research Outcomes and Design Application Vernacular buildings throughout the globe provide informative models of sustainable solutions to construction problems. Yet, those solutions are considered to be inapplicable to contemporary buildings (fig 6.1.2.5).

The research is evident that the government and the city authorities need to act on the different goals and stages of; “medium and long-term actions that will be undertaken suggested the followings for mitigation by 2030” (INDC, 2015), for the housing schemes as the demands will be higher, It would be useful for future to construct to protect the needs of the inhabitants.

The density in Addis Ababa has an impact of rapid urbanisation and public housing development in the urban form, more significant than ever before. Kirkos is characterised by a combination of modern buildings and old residential settlements and now the top two densest subcity in the capital. Tigabu writes, “the neighbourhoods of Addis Ababa are transforming into concrete jungles, with the mushrooming buildings giving the city a whole new identity” Yeshitela, K. et al. (2019)

The government faces the matter of density and provides a fast construction process, since 2000, the housing scheme has produced numbers of housing units imagined in Ethiopian history. Three main problems can be highlighted; high production cost, dependency on imported materials for construction, the industry increasingly relies on expensive imported materials to satisfy the demand for construction, (AACPPO 2017) while In principle, it requires design characteristics and spaces that display the local traditional lifestyles. Also building configuration that does not match with the social context. Which has also revealed a large number of challenges on socio-economic and spatial levels as it did not meet the requirements to provide adequate, affordable housing aiming toward the low-income groups but instead generates segregation spatially and socially

The building technique derived from vernacular to traditional are supposed to imply the contemporary possibilities of the conventional methods, due to numerous new imposed housing regulations, barriers would be harder to be overcome. Which, in return, would enhance the appreciation of such available and sustainable construction materials in the country. “Ethiopia offers still a third example of variations based upon availability of materials, but also reflects climatic differences and levels of technology” (Noble 2007,82)

A useful outcome of the project is a set of cases that can help inform the government about residential housing, the different passive retrofit options and the associated benefits of thermal comfort for the occupiers. The approach to Incremental design discovers focus solutions, that link the relationship between climate, people and buildings.

The main reasons why Addis Ababa is especially interesting for this research is understanding of the traditional African adobe building style and the efficient use of locally available materials extracted from the site. Through a comprehensive understanding and knowledge of Kirkos and the vernacular case study presented a full set of positive attributes, that can be implemented in the new densified proposed model on the same plot, which complies with the building regulations and requirements process of today’s conditions.

After a thorough quantitative study for the different massing against density, appropriate housing typologies that meets the need of the low and middle-income groups were developed. Through comparative analysis, a permeable integration between the communal space and residential zones was strategised.

In the future, it is essential to a city like Addis Ababa, with a high population rate the need for low-income housing is on high demand. By 2020, one out of every five Ethiopian residents will be living in the capital, and by 2030, it is estimated half of the country’s population will be living in urban centres.

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A critical point of view, the proposed outcome design is going against all the principles of environmental design by constructing setbacks on the proposal of orientation, as shading is the key for this project. This was then mitigated through the earthen walls provide a natural climatized barrier and good thermal mass for the indoors and with large overhanging metal sheet roofs, to shade the facades from high solar irradiation and also act to protect the indoor and outdoor spaces from direct sun.

Passive design is great for the climate of Addis Ababa as there is no need for cooling and heating. Main design strategies that drive the project is economically competitive and flexible in construction time and material of the rammed earth, which is technically feasible, compared to the concrete solution. Hence an ideal environmental responsive architecture with a contemporary design, to provide comfortable conditions in a free-running, low energy building for low-income society.

As Noble, A. stated in the Global survey of structural forms and cultural functions; “Vernacular architecture is a historical and geographical record of a culture group related to the physical and social environment�, hence looking at the past to combine the positive attributes of traditional techniques with contemporary social integration is a significant tool to build the prospective cities of tomorrow with its modern requirements.

Figure 6.1.2.5 Earth construction around the world

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APPENDICES Appendix 1: Energy and water bill from vernacular

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Appendix 2: Shadow range low and mid- rise

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Appendix 3: Dataloggers 10 days continuous monitoring // Field work

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Appendix 4: Solar Radiation on Facade

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Appendix 5: UDI

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AUTHORSHIP DECLARATION FORM

COURSEWORK COVERSHEET FORM CA1

UNIVERSITY OF WESTMINSTER MARYLEBONE CAMPUS

I confirm that I understand what plagiarism is and have read and understood the section on Assessment Offences in the Essential Information for Students. The work that I have submitted is entirely my own (unless authorised group work). Any work from other authors is duly referenced and acknowledged​.

STUDENTS MUST COMPLETE THIS SECTION ONLY IN FULL AND IN CAPITALS

Surname Forename AMARE HYAB ARIAM

Registration No:

W

Module Title

Thesis project

Module Code

Assignment No:

1/1

Markers:

ROSA SCHIANO- PHAN

Date Submitted Word Count

Joint

N/A

Assignments:

1

6

9

7

6

3

7

Course

ARCHITECTURE AND ENVIRONMENTAL DESIGN 7AEVD005W.2 02

09

14847

Joint Submission

Please be warned that the University employs methods for detecting breaches of the assessment regulations, including the use of electronic plagiarism detection software where appropriate.

83

2019