Integrated Building Systems, Thermal Comfort & the Summer Palace

AR546 - TECHNOLOGY 4

INTEGRATED BUILDING SYSTEMS, THERMAL COMFORT & THE SUMMER PALACE, LAHORE FORT Maham Neha A. Ansari

Kent School of Architecure - University of Kent Supervisor: Giri Renganathan 19th January 2017 Word Count: 5162

ABSTRACT

This report aims to explore how architectural elements of the vernacular of hot-arid climatic regions were synthesized to achieve thermal comfort in the Summer Palace, built by the Mughals in 1634. A study of the building elements seen in the vernacular integrated in the Summer Palace makes apparent that its features were carefully developed to optimize thermal comfort with respect to the local context.

Aspects of these incorporated strategies can be inherited by contemporary designers to tackle the major problem of sustainability and energy efficiency we face today. To meet the growing energy demands to maintain the thermal comfort of spaces used daily, alternative approaches using natural energy need to be adopted.

Through studies of the vernacular, the aim of this research was to realise where exactly the amalgamation of thermal comfort strategies is seen in the construction of the Summer Palace, and how these could be modified for contemporary architecture.

The research realization was the result of studying features used for thermal comfort in the vernacular for the hot-arid climatic zones and how these were applied to the in the context of the Summer Palace. We see, therefore, how building strategies were used to stitch together building design and physical comfort.

2

ACKNOWLEDGEMENTS

Lahore’s rich history and its various layers, provide boundless inspiration. It is a timeless journey for which I would like to thank my parents and siblings - for their support and belief in my abilities.

To Giri Renganathan, my supervisor for the module, who guided me and helped me with the technicalities of my report, and who helped me develop a unique perspective to approach my research with.

To Tiziano Massarutto, for his insight and feedback that helped refine the report and the communication of my findings.

To Salman Beg and Wajahat Ali of the Aga Khan Cultural Service Pakistan (AKCSP), for guiding me as a young professional as part of the Lahore Fort Documentation Project and for allowing me to use the data we collected, for my research.

And to my colleagues and friends at AKCSP, for supporting me in my research, teaching me the tricks of the trade, and helping me try to understand the complexities of my own culture.

TABLE OF CONTENTS

1. INTRODUCTION

5

1.1 The Climatic and Cultural Context of Lahore & the Summer Palace, Lahore Fort 1.2 Methodology

2. STUDY OF THE INTEGRATED SYSTEMS FOR THERMAL COMFORT IN VERNACLULAR OF THE SAME CLIMATIC AREA

11

2.1 Orientation 2.2 Roof 2.3 Walls, Thermal Mass and Structural Material 2.4 Openings for Light and Shading Devices 2.5 Openings for Ventilation 2.6 Internal Spatial Arrangement 2.7 Water Features

3. SYSTEMS APPLIED TO THE SUMMER PALACE & THEIR EFFECT ON THE THERMAL COMFORT

19

3.1 Orientation 3.2 Roof 3.3 Walls, Thermal Mass and Structural Material 3.4 Openings for Light and Shading Devices 3.5 Openings for Ventilation 3.6 Internal Spatial Arrangement 3.7 Water Features

4. INTEGRATION OF BUILDING SYSTEMS IN CONTEMPORARY ARCHITECTURE

29

5. CONCLUSION

31

BIBLIOGRAPHY APPENDIX 1

1. INTRODUCTION The climate, socio-cultural setup, economy and materials play a key role in shaping the architecture of a region.

Known as the ‘vernacular’, the building style of an area1 is the most accurate representation of the needs, requirements, constraints and cultural values of a region.

The vernacular acts as a mould in which the built environment grows and forms a stage which is animated by daily life.2 The unique dynamics of this environment - from physical constraints to heritage values - are then inherited by later architectural movements, as they have set standards for achieving thermal comfort in spaces according to their intended use.

The civilizations of the past, as Hassan Fathy3 observes, were ‘the most sophisticated of their time, as they managed to survive in the same climatic conditions by making use of locally available energy’. Therefore, they were the pioneers of the building systems that are now a fundamental part of the vernacular. This has resulted in the creation of important examples such as the Summer Palace of the Lahore Fort – which could be studied as precedents for solving issues with achieving thermal comfort.

These precedents of the vernacular cannot be picked up as ready-made solutions for sustainable architecture in the contemporary world. However, they integrate strategies that make use of natural energy – a nuanced understanding of which, could serve as important lessons in approaches to building design and its relationship to physical comfort.

FIG 1.1 An aerial view of the Lahore Fort (rightcenter), Badshahi Mosque (right) surrounded by the dense development of the Walled City of Lahore.

1

(Merrium Webster Dictionary, 2016)

2

(Vandal P. V., 2006)

3

(Fathy, 1986)

6

TECHNOLOGY 4 - INTRODUCTION

1.1 The Climatic and Cultural Context of Lahore & The Summer Palace, Lahore Fort Pakistan’s topography varies considerably from region to region, which allows climatic conditions to be drastically different from one area to another. Lahore, one of Pakistan’s oldest cities, sits between the River Ravi and the north-eastern border with India (Fig 1.12), in the climatic zone classified as ‘Bsh’ by the Koppen-Geiger Climate Classification4 system (Fig 1.13). This means that the climate of Lahore is classified as ‘Arid’, the Precipitation as ‘Dry Summer’ and the Temperature as ‘Hot Arid’.

FIG 1.12 Map showing Lahore’s location in the INdian Subcontinent

Lahore experiences a five-season semi-arid climate, where the primary summer months are March to September.

Spring/Early Summer begins in February and lasts till April, the dry summer with occasional heatwaves from April to June, and from July till September Lahore sees heavy monsoon rainfall and humidity, before the arrival of a dry autumn till November. From November dry winters begin, with dense fog and last till mid-February. The highest temperature recorded in Lahore is 48.3⁰C and the lowest recorded is -1⁰C5 (Fig 1.14).

January February March

Lahore (1931-2014) Temperature (C) Highest Maxi- Lowest Minimum mum 27.8 (1952) -2.2 (1935) 33.3 (1953) 0.0 (1934) 37.8 (1942) 2.8 (1945)

121.2 (1981) 509.0 (1934) 254.5 (1934

April May June July August September October November December Annual

46.1 (1941) 48.3 (1944) 47.2 (1972) 46.1 (1948) 42.8 (1947) 41.7 (1938) 40.6 (1951) 35.0 (1943) 30.0 (1998) 48.3 (1944)

141.0 (/1983 129.0 (1958) 208.6 (1996) 477.9 (1981) 640.0 (1996) 523.2 (1954) 155.0 (1985) 77.9 (1997) 111.8 (1967) 1232.5 (1997)

Month

10.0 (1940) 14.0 (1977) 18.0 (1977) 20.0 (1974) 19.0 (1980) 16.7 (1972) 8.3 (1949) 1.7 (962) -1.1 (1950) -2.2 (1935)

Monthly Heaviest Rainfall (mm)

FIG 1.13 (left) - Koppen-Geieger Climate Classification Map. Lahore sits in zone ‘Bsh’ Climate; Arid Precipitation; Dry Summer - Temperature; Hot Arid.

FIG 1.14 (right) - Temperature Table for Lahore 4

(Institute for Veterinary Public Health , 2011)

5

(Pakistan Meteorological Department)

7

TECHNOLOGY 4 - INTRODUCTION

Lahore’s rich historical background is represented by the various styles of architecture that were built under different regimes, which form the vernacular of the area. The Lahore Fort is one such example of a complex of public, semi-public and private spaces constructed for everyday use between the 16th - 18th centuries, developing under the stylistic preferences of successive rulers. The Summer Palace of the Lahore Fort, was built in 1634 by the Mughal Emperor Shah Jehan6, as his private residence specifically to be used during the summer season.

Therefore, it serves as an important part of the v­ernacular of Lahore and an important lesson in integrated systems to achieve thermal comfort in a ‘Hot Arid’ climatic zone (Fig 1.15).

Original River-bed

FIG 1.15 (left) Lahore City Map FIG 1.16 (right) Lahore Fort Map, showing the Summer Palace Location

The Summer Palace is located on the first floor level of a three-storey complex in the North-Western part of the Lahore Fort. (Fig 1.16) As it was intended to be used as a private palace, it was built on a lower floor than the public courtyard called the Shish Mahal (Hall of Mirrors). The Shish Mahal, used as the king’s courts and the adjacent courtyard space surrounded by smaller pavilions, form the roof of the Summer Palace, complete with a fountain in the centre. (Fig 1.17)

FIG 1.17 Aerial View of the Lahore Fort, Showing the Shish Mahal Courtyard that forms the roof of the Summer Palace and the West Facade of the Summer Palace 6

(Aga Khan Cultural Service Pakistan , 2016)

8

TECHNOLOGY 4 - INTRODUCTION

FIG 1.18 (a) Western facade of the Summer Palace (b) Drawing of the Western facade of the Summer Palace showing three levels of the Complex.

The Summer Palace is a series of huge high-vaulted halls placed around a solid mass in the centre, the use of which has not been determined yet. The high vaulted spaces lead to a long corridor running parallel to the North façade, connecting to the private chambers. It is connected to the North-Western section of the main fortification wall, and the five large arches with perforated screens7 seen on the western elevation form its main façade. (fig 1.18a) The spaces were arranged so that the more private areas ran along the Northern Façade (fig 1.19b), parallel to where the river originally flowed.8 Although the building has decayed over time and the surrounding context has changed drastically, the building elements used in the Summer Palace ensure that a people get instant respite from the harsh summer heat, from the moment they step into the space. The aim of this report is to analyse which building features help achieve this effect in the Summer Palace.

7

Perforated screens are locally known as ‘jaalis’

8

(Aga Khan Cultural Service Pakistan , 2016)

9

TECHNOLOGY 4 - INTRODUCTION

FIG 1.19 (a) (Top) Isometric Wireframe srawing of the Summer Palace showing the massing of the vaulted spaces (b) (Left) Plan of the Summer Palace showing the semi-private hall (dark green) and the private spaces (light green) 0

10

2

6

14m

TECHNOLOGY 4 - INTRODUCTION

1.2 Objective and Methodology The main aim of this study is to learn and understand how the structure, spatial design, cooling techniques and aspects of vernacular architecture of the time dealt with providing thermal comfort in the Summer Palace, Lahore Fort and, subsequently, what aspects of it can be inherited by contemporary designers.

To study this fusion of building technologies, this report studies the vernacular architecture of similar climatic conditions to understand the local context, its requirements and to identify building systems used to achieve thermal comfort. Photographs and orthographic drawings of the Summer Palace were collected and integrated features analysed through drawings and sketches, looking at the thermal comfort requirements from the studies of the vernacular. Finally, the report discusses possible ways to incorporate the building systems used at the Summer Palace in modern design, through a series of diagrams and sketches.

FIG 1.2 Photograph of the high valuted space inside the Summer Palace

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2. STUDY OF INTEGRATED SYSTEMS FOR THERMAL COMFORT IN THE VERNACLULAR “Traditional structures”, Allen Noble points out, “normally reflect their surroundings”1 – As a result, the vernacular of an area is a combination of techniques carefully developed over centuries, to ensure thermal comfort using local resources. The Summer Palace is a clear reflection of the requirements of the surrounding area, but its decay over the years makes it challenging to analyse its systems quantitatively. A study of the building elements and devices in the vernacular for hot-arid climatic zone, therefore, makes it easier for us to understand systems of the Summer Palace.

2.1 Orientation The sun’s position and the direction of the prevailing winds must be determined to establish optimum orientation. In the northern hemisphere, the East-facade receives solar radiation in the morning and the West façade, in the afternoon, while the North and South receive little radiation due to the high altitude summer sun.

FIG 2.1a Optimum orientation for air velocity

FIG 2.1b Orientation for the sun

FIG 2.1c Orientation for for buildings in Cairo

By orientating the openings of a building at a 45 degree angle2, the air velocity increases, distributing the air evenly within the building. Cross ventilation can also be facilitated while trying to achieve the optimal orientation for solar gain by arranging rooms in a stepped/recessed pattern, which would alter the wind route.

(Fig 2.1a) In the Hot-Arid climatic zone, devices such as the wind-catchers were used to free the building to be orientated for optimal sun.

In the vernacular, we look at Cairo, where the wind blows from the North-West, therefore, the optimal orientation of the building is north-east to south-west3, perpendicular to the wind. This way, the north façade is exposed to the sun at the summer solstice from 5-9am at 1 degree angle and the south façade at 6 degrees.

The openings on the south façade would not be penetrated by solar radiation until the winter, when the altitude of the sun is lower, which allows the sunlight to penetrate the interior for warmth. 4 1

(Noble, 2007)

2

(Koch-Nielsen, 2007)

3

(Fathy, 1986)

4

(Fathy, 1986)

12

TECHNOLOGY 4 - THE VERNACULAR

2.2 Roof The roof is exposed to the greatest amount of solar radiation – the outer surfaces of the roof absorb the heat and transmit it to the inner surface, increasing the air temperature inside, affecting thermal comfort.

Roof, therefore, is an important factor that affects thermal comfort. Flat roofs experience solar radiation throughout the day, so the entire surface transfers heat inside. However, if the ceiling does not have a cavity or heavyweight construction, the heat gains are excessive.

Solutions to this are double roof with hollow bricks, a roof garden that transpires to cool the roof or insulating materials such as Styrofoam and lightweight blocks. However, according to Koch-Neilsen, these ‘would prove costly for majority of the (hot-arid climatic zone’s) inhabitants’5, therefore, the most effective way to achieve thermal comfort is to design the roof to suit popular traditions.

In hot arid countries, domed and pitched roofs ‘moderate’6 heat gains as the roof is partially shaded the entire day. The surface acts as a radiator – the sunlit area transfers its heat to the cooler, shaded area, which releases heat back into the outside air.7 (fig 2.21) The surface area of these roofs is also larger which provides an opportunity for heat to be lost as winds pass over it.

An example from the vernacular is the Bee-hive huts in Syria (Fig 2.22) - a building practice in use since around 37000 BC. These homes are built using mud bricks which are stacked in a conical shape allowing hot air to travel upwards so the living spaces stay cool.8

FIG 2.21- (left) Heat transmission from the domed roof FIG 2.22 (a) - (bottom left) Bee-hive houses, Syria (b) (bottom right) Interior of the dome of mud bricks

5

(Koch-Nielsen, 2007)

6

(Koch-Nielsen, 2007)

7

(Fathy, 1986)

8

(Aburawa, 2011)

13

TECHNOLOGY 4 - THE VERNACULAR

2.3 Walls, Thermal Mass and Material As the east and west facades receive the most solar radiation, the walls should be able to reduce the heat gained by the surfaces. Koch-Neilsen suggests that ‘the walls of rooms used throughout the day should be heavyweight’9 - This would allow thermal mass to regulate temperature inside the building by absorbing it and slowing down its release inside.

An example is a small house in Kot Karamat village near Lahore, Pakistan, where a simple structure is made of thick mud walls, which protect against the harsh summer heat. 10 (Fig2.31) Apart from using massive mud walls, cavity walls could be used or the geothermal properties of the ground could also be taken advantage of, by building into the ground or using it as the floor – In hot dry areas, it is common to sit on the ground which ‘shows the cultural and thermal awareness of the cooling potential of floors’. 11

FIG 2.31 Section of typical house in Kot Karamat village, showing the use of thermal mass for cooling

To maintain thermal comfort inside the building envelope, its material has to be able to reflect the heat rather than absorb it. This component is called ‘reflectivity’, which defines the amount of heat not gained by the surface. Generally associated with colour, they can be used as a guide to choosing insulative material. (Fig. 2.32 b) A surface absorbs (gains heat) or emits (heat release). A roof with a high reflectivity and emissivity value is best suited to save cooling energy during the warm summer months. High emissivity value is also important for avoiding certain areas being warmer than their surroundings.12 (Fig. 2.32 c)

9

(Koch-Nielsen, 2007)

10

(Mumtaz, Architecture in Pakistan, 1989)

11

(Koch-Nielsen, 2007)

12

(Reflectivity, Emissivity Important Factors When Selecting A Cool Roof, 2016)

14

TECHNOLOGY 4 - THE VERNACULAR

FIG 2.32 (a) Diagram showing the proccess of reflection, absorptivity and emissvity of heat

FIG 2.32 (b) Reflectivity values in %

FIG 2.32 (c) Aborptivity and Emissivity values in %

15

TECHNOLOGY 4 - THE VERNACULAR

2.4 Openings for Light and Shading Devices To protect the building from solar gain and to avoid glare from the surroundings, windows in hot climatic zones are kept small and directed towards the sky. The most appropriate form of daylight for such areas is the use of indirect, internally reflected light from high level openings which is achieved by using different types of shading devices, as seen in the vernacular.

The first is the Venetian Blind, made of thin moveable slats, so that the angle of the light can be adjusted. The blinds when drawn completely obstruct the view and dim the incoming light, however, if the slats are made of metal, they absorb the incoming radiation and release it slowly throughout the day.

FIG 2.41 (a) Use of the Mashrabiya in Jamal ad Din Manzil, Cairo FIG 2.42 (b) Typical mashrabiya used for privacy and shade

The most commonly used is the ‘Mashrabiya’, which controls the passage of light; controls the airflow; reduces air temperature; increases humidity of air and ensures privacy.13 (Fig 2.41a) It is a perforated screen with various styles of openings - at eye-level the balusters are set close together with a fine mesh to reduce dazzle and direct sunlight, and the perforations above eye level are larger to compensate for the dimming of light. An example of this is seen in Jamal ad Din Manzil, Cairo (Fig 2.41b). The characteristic shape of the lattice distributes the outside view and super-imposes it on a decorative pattern and also serves as an important social feature – a privacy screen14. It is a universal feature sometimes used between rooms for cross ventilation - in India it is known as the jaali.

Regardless of the type, the shading device should be placed outside an opening and should be made from light, reflective material to avoid absorption of heat.15 13

(Fathy, 1986)

14

(Abdel-Gawad, 2012)

15

(Koch-Nielsen, 2007)

16

TECHNOLOGY 4 - THE VERNACULAR

2.5 Openings for Ventilation Ventilation can be facilitated by creating differences in air pressure and temperature. By placing the larger openings facing the wind and smaller openings on the leeward side, lower air velocity is created, regulating circulation in the room.16 By locating openings at different heights, the hot air rises up through convection and forces the cooler air down into the living space.

The Mashrabiya is also used as a ventilation device - The wooden frame absorbs the air’s moisture, so when the mashrabiya is hit with light, humidity from the wood is released into the dry air flowing through, humidifying it.17 The rate of cooling and humidification is increased by increasing the baluster size, which would absorb and release water faster and over a longer period of time. (Fig 2.51)

FIG 2.51 (above)- Use of the Mashrabiya for ventilation FIG 2.52 (right)- Use of Badgir for ventilation FIG 2.53 (below)- Malqaf found in houses in Hyderabad, Paksitan

The Malqaf or the wind catcher is a shaft rising up the building with an opening facing the prevailing wind. In densely populated cities, such as Hyderabad, Pakistan,18 (Fig 2.53) where masses of buildings reduce wind velocity at street level, it traps the wind from high above, where it is cooler and channels it down into the building.

A type of malqaf is the Badgir in which the top opens on four sides to catch breezes from any direction and the shaft is divided into long tubes that extend down to allow the breeze to reach the living space directly. (2.52)

16

(Koch-Nielsen, 2007)

17

(Fathy, 1986)

18

(Mumtaz, Architecture in Pakistan, 1989)

17

TECHNOLOGY 4 - THE VERNACULAR

2.6 Internal Spatial Arrangement The efficiency of thermal comfort strategies is greatly impacted by the massing and planning of the building.

An example of this is the ‘Qa’a’ of Muhib Ad-din Ash-Shafi in Cairo built in 1350 AD.19 The qa’a is composed of 3 connected spaces: a large central high-roofed circulation area (durqa’a) and two iwans on either side.

The dur-qaa has high clerestory windows covered with mashrabiyas that provide diffused lighting and air outlets. One iwan is connected to the malqaf, and channels the cool breeze inside. Once inside, the air rises into the dur-qaa through convection and escapes through the mashrabiya. The qaa is surrounded by rooms which protect it from external heat. This arrangement ensured maximum temperature difference to promote convection. (Fig 2.61)

People of the hot-arid climatic regions also open their houses inwardly onto open courtyards. ‘This arrangement provides drops in air temperature of 10-20 C° at night’.20 In the evening, the warm day air rises and is gradually replaced by the already cooled night air through convection. This cool air cools the surrounding space over-night and in the morning, the air of the courtyard and the surrounding rooms heat slowly and remain cool till the sun shines into the courtyard directly. In this way, the courtyard serves as a reservoir of coolness. The courtyard concept is universally applied in the vernacular architecture of hot arid regions. (Fig 2.62)

FIG 2.61 (centre) Massing of spaces in the Qa’a’ of Muhib Addin Ash-Shafi used to aid ventilation FIG 2.62 (right) Courtyard at the Jamal ad din Manzil, Cairo 19

(Fathy, 1986)

20

(Fathy, 1986)

18

TECHNOLOGY 4 - THE VERNACULAR

2.7 Water Features In the vernacular, the fountain occupied a place in the middle of a courtyard to increase the humidity of the space. However, in areas where there was not enough water pressure to make fountains work, the ‘salsabil’ was used.

FIG 2.71 (centre) Salsabil found at La Zisa Palace, Palermo

FIG 2.72 (centre) Salsabil found at Mughal Emperor Humayun’s Tomb in Dehli

‘Salsabil’ means the ‘pond of Paradise’ in Islamic tradition, and is a device used to facilitate evaporative cooling and increase humidity. It consists of ‘a water spout at the back of a niche; an inclined marble slab on which water flows, and a thin water channel that connects to a pool in the centre of a courtyard’21. The ‘salsabil’ is a transposition of the fountainhead outside the fountain and the wave pattern carving represents wind and water. 22

21

(Tabaa, 1986)

22

(Fathy, 1986)

19

3. SYSTEMS APPLIED TO THE SUMMER PALACE & THEIR EFFECT ON THE THERMAL COMFORT

The architecture of a region is the result of ‘repeated cycles of trial and error and embodies the experience of generations of builders’.23 Buildings such as the Summer Palace inherit these experiences in the form of building techniques that are applied to achieve thermal comfort. The study of the vernacular, therefore, has presented a set of design principles for the hot-arid climatic zone that can be used to analyse elements of the Summer Palace that effect its thermal comfort.

3.1 Orientation To establish the optimum orientation, the sun’s position and the direction of the prevailing winds must be determined.24 Lahore, like Cairo, is also located in the northern hemisphere, therefore receives the most solar radiation on the East Façade in the morning and the West façade, in the afternoon. The optimum orientation of buildings in Lahore, therefore, should be North-East to South-West, ‘perpendicular to the direction of the wind’25.

FIG 3.11 (a) - (left) Wind Direction from March -May

FIG 3.11 (b) - (right) Wind Direction from June to September

Since Lahore experiences dry heat from March to June and warm, humid monsoon from July to September, the direction of the prevailing wind changes. From March to May it flows from the North-West and from June to September, from the South-East.26 (Fig)

23

(Building Research Establishment , 1980)

24

(Koch-Nielsen, 2007)

25

(Fathy, 1986)

26

(WindFinder, 2016)

20

TECHNOLOGY 4 - THE SUMMER PALACE

FIG 3.12 Sun Chart for Lahore showing the Summer Palace orientation

The Summer Palace, as shown in fig-, is orientated at approximately a 20 degree angle27 from the North.

This allows its five main openings on the North-Western façade to face the prevailing wind and to receive the low-heat evening sun between 5pm till sunset. The North-Eastern façade receives the early morning sun from dawn till 8am. 28 Fig – is a shadow study showing the palace’s solar gain at 9am, noon and 3pm at the summer solstice.

FIG 3.13 Shadow Studies (Summer Solstice)

27

(University of Oregon Solar Radition Monitoring Lab, 2016)

28

(University of Oregon Solar Radition Monitoring Lab, 2016)

21

TECHNOLOGY 4 - THE SUMMER PALACE

3.2 Roof The Summer Palace has a flat roof that is used as a courtyard space for the Shish Mahal above it. The roof is, therefore, exposed to solar radiation throughout the day.

FIG 3.21 Courtyard on the roof of the Summer Palace

The Summer Palace roof surface is covered in white marble which reflects the heat. The reflectivity value of polished marble is 30-70%29. The roof is also partially shaded by the pavilions of the Shish Mahal courtyard throughout the day as a result of which, the surface would act as a radiator30, transferring heat from the sunlit area, to the cooler shaded area.

The roof is constructed in brick and lime mortar and the interior spaces have high, vaulted ceilings. This has resulted in the roof thickness to range from 1m at highest point of the vault to 4m.31 (Fig 3.22a) - the high vaulted spaces heat up the air inside, facilitating convection (Fig 3.22b) . Furthermore, the fountain in the centre of the Shish Mahal courtyard, now un-functional, would also have used evaporative cooling to keep the temperature of the roof low.

FIG 3.22 (a) Roof Thickness 29

(Engineering Toolbox, 2016)

30

(Fathy, 1986)

31

(Aga Khan Cultural Service Pakistan , 2016)

(b) Heat Transmission into the Summer Palace

22

TECHNOLOGY 4 - THE SUMMER PALACE

3.3 Walls, Thermal Mass and Structural Material The thickness of the outer walls of the Summer Palace ranges depending on its placement – the east and west facades receive the most solar radiation, therefore the wall thickness on the Western façade is 5.9m, whereas the Northern façade is 1.2m32. The octagonal part of the palace is where the building supports the Shish Mahal above it; a large mass of about 16m thickness is seen. This mass is used to create 3 wind tunnels that facilitate air movement.33

FIG 3.31 - Section through the North facing private spaces

The entire building envelope, including the roof, is constructed in bricks and lime mortar – the reflectivity, absorptivity and emissivity values of red brick are 40%, 65-80% and 85-95%34 respectively, which allows thermal mass to regulate temperature inside the building.

Furthermore, according the geo-technical studies of the stratification of the ground, the entire Lahore Fort appears to be built on a mound that faced the original river35. The sectional massing of the North-facing spaces as seen in Fig 3.31 also seems to suggest the same. Therefore, the Summer Palace is also making use of geothermal properties from the earth that cool the palace from the sides not exposed to the sun.

32

(Aga Khan Cultural Service Pakistan , 2016)

33

(Khan, Archaeology below Lahore Fort,UNESCO World Heritage Site, Pakistan: The Mughal Underground Chambers, 2011)

34

(Koch-Nielsen, 2007)

35

(Khan, Archaeology below Lahore Fort,, 2011)

23

TECHNOLOGY 4 - THE SUMMER PALACE

3.4 Openings for Light and Shading Devices The orientation of the Summer Palace makes the five arches on the North-West façade, the only source of direct sunlight. (Fig 3.41a)

FIG 3.41 (a) (above) Plan showing main solar access (b) (Top right) Mashrabiya of the main arch (c) Mashrabiya patterns

To protect the building from excessive solar gain and ensure the privacy of the palace, the ‘Mashrabiya’ is used. The five arches are covered with two patterns of fine mesh up to eye-level, (Fig 3.41 b-c) and a wider mesh above that, to reduce dazzle like the vernacular suggests. The pattern found on the north façade has wider openings, to distribute the daylight evenly.

The depth of the room for optimum daylight should be twice the opening’s height36. Looking at one of the five bays of the arched mashrabiyas as a prototype, it is seen that the depth of the bay is thrice the window’s height. Nevertheless, according to the BS 8206 criteria for daylighting, the average daylight factor (ADF) should be between 2 -5%.37 The approximate ADF for one bay is 4.03%, (Fig 3.42) therefore, the depth of the room is sufficient. However, it only illuminates the halls next to it, so additional lighting is required for spaces further away. Similarly, the approximate ADF for the Northern openings is 5.03%, but the lighting does not extend to the corridor. (Fig 3.43)

36

(Nick Baker, 2014)

37

(CIBSE, 2016)

24

TECHNOLOGY 4 - THE SUMMER PALACE

FIG 3.42 Average daylight factor of one of the main five arches (west facade)

FIG 3.43 Average dayligth factor of the North facade spaces

25

TECHNOLOGY 4 - THE SUMMER PALACE

3.5 Openings for Ventilation The five main arches of the North-West façade also use the ‘mashrabiya’ as a ventilation device. As seen in Section 3.1, the orientation of the palace is perpendicular to the wind direction. The velocity of the wind is increased as is passes through the lattice of the mashrabiya, facilitating ventilation. The cooling and humidification is increased through adiabatic cooling as the wind enters the interior spaces and flows over the indoor water channels (salsabil). The interior spaces have high-vaulted ceilings which allow the warm air the rise up through convection so that the dense, cool air sinks into the living space.

FIG 3.51 (a) Mashrabiya for ventilation (b) Rate of ventilation from main western arch

Studying one of the main five arches and its internal bay it is seen that the ventilation is mostly single-sided.

The ventilation through the mashrabiya would affect the rate of ventilation of the palace. To calculate rate of ventilation of one mashrabiya, the total area of the perforations in the mashrabiya38 is used, and the coefficient for the flow of volume is assumed 0.25. The average wind speed of Lahore is 6 knots (3.09 m/s)39.

38

(Aga Khan Cultural Service Pakistan , 2016)

39

(WindFinder, 2016)

26

TECHNOLOGY 4 - THE SUMMER PALACE

3.6 Internal Spatial Arrangement The massing of the Summer Palace, like the qa’a studied in Section 2.6, is composed of high-roofed vaulted halls connected to bays with lower ceilings that protect them from external heat. Although the high-vaulted ceilings do not have high clerestory windows for air outlets, they provide diffused lighting reflected from the mashrabiya, a space that facilitates convection and allows the warm air to rise up to cool the living space.

The connected bays have mashrabiyas that channel the cool breeze into the hall which ensures maximum temperature difference to promote convection.

In plan, the high vaulted spaces arranged around a solid central mass that lead to a corridor connecting to the private rooms that run along the North façade. The five mashrabiyas on the West façade and wind tunnels allow the air to enter, and the halls on either side of the solid central mass pull the air in towards the spaces at the back. (Fig 3.61) The mashrabiyas on the North façade ventilate the private spaces and also are protected from direct solar gain throughout the day.

FIG 3.61 Summer Palace plan optimises wind channeling

The typical courtyard arrangement of the hot arid climatic zone is seen in the Shish Mahal plan above the Summer Palace. It uses its passive cooling strategy not only to maintain thermal comfort in the Shish Mahal, but also to cool the roof of the Summer Palace.

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TECHNOLOGY 4 - THE SUMMER PALACE

3.7 Water Features The Summer Palace also used the traditional ‘salsabil’ to increase humidity in the space through evaporative cooling (also known as direct adiabatic cooling). The inclined marble slabs are placed in the cascades located on all four sides of the central solid space.

FIG 3.71 Shish Mahal fountain and Summer Palace ‘salsabil’

However, unlike the traditional salsabil, where the pressure of the water was created by the marble slab and fed into a central fountain, the salsabil of the Summer Palace was fed water through the fountain located on the courtyard above it. The fountain of the Shish Mahal courtyard, not only kept the roof cool, but was also connected to the salsabil through a water spout that opened up in a niche of the Summer Palace and allowed the water to flow over the marble slab. The water from the salsabil cooled the interior of the Summer Palace by increasing the humidity of the dry air entering through the mashrabiyas.

FIG 3.72 (a) Salsabil Location (b) Summer Palace Salsabil today

28

TECHNOLOGY 4 - THE SUMMER PALACE

FIG 3.72 Diagram showing the adiabatic cooling process by the salsabil

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4. INTEGRATION OF BUILDING SYSTEMS IN CONTEMPORARY ARCHITECTURE The optimum orientation of the building, as seen the 3.1 should be 20-30 degrees from the North, so that it is receives the low-heat sun from dawn till 8am, and from 5pm till sunset40. (Fig 4.1) This would also allow the wind to facilitate the ventilation and distribute air evenly throughout the building41. However, in Lahore’s dense urban fabric, it is very hard to find a site large and open enough to orientate the entire building. Therefore, features seen in the Summer Palace can be adapted to contemporary sustainable architecture for thermal comfort.

FIG 4.1 Shadow studies for optimum orientation

In terms of the massing and internal spatial arrangement, a double height central space could be provided, surrounded by rooms on all sides, like a covered courtyard. The rooms surrounding the indoor courtyard would act as a barrier from external heat42 and use windows to draw in the air from the outside, just like the Summer Palace bays. These spaces could open into the indoor courtyard, using the double height space as the main circulation for air movement.

The height of the space would facilitate convection, leading to the warm air rising up and the cool air sinking down to the living space. (Fig 4.2a) The placement of air outlets at the top of the high ceiling, covered with mashrabiyas, would increase the rate of ventilation, and also be a source of internally reflected daylight. (Fig 4.2a) Mashrabiyas could also be used on the facades exposed to direct sunlight, however, these should be covered with openable glass panes to avoid excessive dust to enter the house, and FIG 4.2 (a) (Top) Ideal massing showing ventilation (b) (Bottom) Daylighting strategies

40

(University of Oregon Solar Radition Monitoring Lab, 2016)

41

(Koch-Nielsen, 2007)

42

(Fathy, 1986)

30

TECHNOLOGY 4 - CONTEMPORARY ARCHITECTURE

to warm the house during the winters. Since the ideal average daylight factor is between 2-5%43, the rooms surrounding the courtyard should be only twice as deep as the height of the opening.

The roof of the double height space could be domed or vaulted to be partially shaded from the sun. This would transmit the heat from the sunlit surface to the shaded surface and release heat back into the outer air. (Fig 4.3a) The heat transmitted inside would aid convection.

The incorporation of water features on the roof, like the Summer Palace, would greatly aid the thermal comfort of the inside spaces. The roof could, instead of a standing water body, have water channels, to cool the roof and the air inside. (Fig 4.3b) The water channels could also feed water to a cascade inside the courtyard that humidifies the incoming air. (Fig 4.3c) This cool air subsequently cools the surrounding spaces and the air of the courtyard and this way, the courtyard serves as a reservoir of coolness.

The building envelope, like the Summer Palace, should be ‘heavyweight’44 and made of material that has a high thermal mass, to slow down the transmittance of heats indoors. The walls, therefore, could be thick Cavity walls made of brick, with Styrofoam insulation. Brick is the most suitable material for Lahore as it is locally produced in nearby villages, and also has a high thermal mass, an absorptivity value of 65% and an emissivity value of 85%45. Similarly the roof could also be insulated using a combination of hollow bricks and Styrofoam/polyurethane foam. (Fig 4.3d) However, it should be noted that between July and September, Lahore experiences warm, humid heat accompanied with heavy monsoon rainfall.46 During this time, the use of water features to humidify the incoming air would have to be discontinued and the velocity of the air movement would need to be supplemented by the use of electric fans and de-humidifiers to maintain indoor comfort.

43

(CIBSE, 2016)

44

(Koch-Nielsen, 2007)

45

(Koch-Nielsen, 2007)

46

(Pakistan Meteorological Department)

FIG 4.3 (a) (Top) Roof Form (b) (Top-centre) )Adiabatic cooling for roof (c) (Bottom-centre) Adiabatic cooling for indoor courtyard (d) (Bottom) Heat transfer through Cavity Wall

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5. CONCLUSION

A study of the vernacular and which features of it were used or adapted in the Summer Palace makes it easier to understand the integrated building systems used to provide thermal comfort. It gives us a set of guidelines to use while designing in Lahore’s and what aspects of the vernacular can be inherited by contemporary designers in Pakistan.

In the hot-arid climate, 70-80% of lifetime total energy of a building is used for systems to maintain thermal comfort’47. In the foreseeable future, if the demands for energy are to be met, alternative and sustainable approaches need to be adopted to promote energy efficiency. As Hassan Fathy suggests, ‘This topic can open the door to recognition of the contribution traditional knowledge can make to the solution of many contemporary problems’48. Examples seen in the vernacular from the hot-arid climatic zones provide the contemporary designer with countless features and ideas that could be translated into the architecture of today for a more sustainable approach. More specifically, by studying the systems integrated to maintain the thermal comfort in the Summer Palace, a set of guidelines and systems were established for use in contemporary architecture in the future.

The Summer Palace is, therefore, an important lesson in how each building element comes together to ensure that the space offers instant respite to the person stepping in from the extreme heat outside. It makes use of its orientation, roof type, building envelope, materials, openings and spatial arrangement to ensure thermal comfort.

47

(Koch-Nielsen, 2007)

48

(Fathy, 1986)

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TECHNOLOGY 4 - BIBLIOGRAPHY

BIBLIOGRAPHY Abdel-Gawad, A. (2012). Veiling Architecture: Decoration of Domestic Buildings in Upper Egypt 1672-1950.

Cairo: American University Cairo Press.

Ackerman, J. (1966). Palladio. London: Penguin Group.

Aga Khan Cultural Service Pakistan . (2016). Lahore Fort Picture Wall - Documentation, Presentation and Promotion Project. Lahore: Aga Khan Cultural Service Pakistan (Aga Khan Trust for Culture).

Building Research Establishment . (1980). Building in Hot Climates. Department of the Environment.

Engineering Toolbox. (2016). Reflectivity of Materials. Retrieved from Engineering Toolbox: http://www. engineeringtoolbox.com/light-material-reflecting-factor-d_1842.html Fathy, H. (1986). Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates (5th ed.). United Nations University.

Heath, K. W. (2009). Vernacular Architecture and Regional Design - Cultural Process and Environmental Response (Illustrated ed.). Oxford: Elsevier.

Institute for Veterinary Public Health . (2011). World Maps of Kรถppen-Geiger climate classification. Retrieved November 2016, from http://koeppen-geiger.vu-wien.ac.at/ Jehan, M. (2015). Traditional Arts and Crafts of Turnery or Mashrabiya. Rutgers MA Research.

Khan, R. (2011). Archaeology below Lahore Fort,UNESCO World Heritage Site, Pakistan: The Mughal Underground Chambers. Lahore: Global Heritage Fund Preservation Fellowship.

Koch, E. (2002). Mughal Architecture: An Outline of Its History and Development (1526-1858) (2nd ed.). New Delhi: Oxford University Press.

Koch-Nielsen, H. (2007). Stay Cool - A Design Guide for the Built Environment in Hot Climates (2nd ed.).

London: Earthscan.

Merrium Webster Dictionary. (2016, January). Merrium Webster . Retrieved from https://www.merriamwebster.com/dictionary/vernacular Mumtaz, K. K. (1989). Architecture in Pakistan (2nd ed.). Singapore: Butterworth Architecture.

Noble, A. (2007). Traditional Buildings - A Global Survey of Structural Forms and Cultural Functions . London: I.B. Tauris & Co. Pakistan Environmental Planning & Architectural Consultants Ltd. (1993). The Walled City Lahore. Lahore: Lahore Development Authority.

Pakistan Meteorological Department. (n.d.). Pakistan Meteorological Department. Retrieved November 2016, from http://www.pmd.gov.pk/ Reflectivity, Emissivity Important Factors When Selecting A Cool Roof. (2016, January). Retrieved from FacilitiesNet: http://www.facilitiesnet.com/ Singh, M. K., Mahapatra, S., & Atreya, S. (2008). Bioclimatism and vernacular architecture of north-east India.

Building and Environment.

Tabaa, Y. (1986). The 'Salsabil' and the 'Shadirwan' in the Medieval Islamic Courts. In Environmental Design: The Garden as a City (p. 37). Retrieved from Archnet.org: http://archnet.org/system/publications/ contents/4348/original/DPC0701.pdf?1384785217 Tadgell, C. (1990). The History of Archtiecture in India. London: Archietcture Design and Technology Press.

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TECHNOLOGY 4

Tagdell, C. (2008). Islam: From Medina to the Magreb and from the Indies to Istanbul (illustrated ed.).

Routledge.

University of Oregon Solar Radition Monitoring Lab. (2016, January). Sun Path Chart. Retrieved from University of Oregon Solar Radition Monitoring Lab: http://solardat.uoregon.edu/SunChartProgram.html Vandal, P. V. (2006). The Raj, Lahore & Bhai Ram Singh. Lahore: National College of Arts.

WindFinder. (2016). WindFinder- Lahore Allama Iqbal Airport. Retrieved from WindFinder: https://www. windfinder.com/windstatistics/lahore_allama_iqbal_airport Zhai, Z. (., & Previtali, J. M. (2009). Ancient Vernacular Architecture: Characteristics, Categorization and Energy.

Energy and Buildings.

Aburawa, A. (2011, July 13). Syria’s Beehive-Shaped Green Architecture. Retrieved from Green Prophet: https://www.greenprophet.com/2011/07/syrias-beehive-architecture/

ILLUSTRATIONS All orthographic drawing (used for diagrams or otherwise) are courtesy of the Aga Khan Cultural Service - Pakistan All other images and diagrams are the author’s own, except the following: 1.1 J. Zakariya - Flickr.com 1.12 https://commons.wikimedia.org/wiki/Atlas_of_India#/media/File:Modern_india.png 1.13 Ali Zifan, 2016 1.3 Pakistan Meteorological Department. (n.d.). Pakistan Meteorological Department. Retrieved November 2016, from http://www.pmd.gov.pk/ 2.1a+b, 2.21, 2.32 Koch-Nielsen, H. (2007). Stay Cool - A Design Guide for the Built Environment in Hot Climates (2nd ed.). London: Earthscan.

2.1c, 2.51, 2.52, 2.61 Fathy, H. (1986). Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates (5th ed.). United Nations University.

2.22 Aburawa, A. (2011, July 13). Syria’s Beehive-Shaped Green Architecture. Retrieved from Green Prophet: https://www.greenprophet.com/2011/07/syrias-beehive-architecture/ 2.31 Mumtaz, K. K. (1989). Architecture in Pakistan (2nd ed.). Singapore: Butterworth Architecture.

2.41, 2.62 http://www.touregypt.net/featurestories/khawaga.htm 2.53 https://s-media-cache-ak0.pinimg.com/736x/1f/12/8f/1f128f8346dc23171370f4c616539e8d.jpg 2.71https://ocw.mit.edu/courses/architecture/4-615-the-architecture-of-cairo-spring-2002/lecture-notes/ lec4/ 2.72 https://s-media-cache-ak0.pinimg.com/564x/b5/9c/ed/b59ced5106390da471ffb97ccafd1ab3.jpg 3.11 WindFinder. (2016). WindFinder- Lahore Allama Iqbal Airport. Retrieved from WindFinder: https://www. windfinder.com/windstatistics/lahore_allama_iqbal_airport 3.12 University of Oregon Solar Radition Monitoring Lab. (2016, January). Sun Path Chart. Retrieved from University of Oregon Solar Radition Monitoring Lab: http://solardat.uoregon.edu/SunChartProgram.html 3.41 flickr.com

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APPENDIX 1

APPENDIX 1 Neha Ansari <maham.neha.andaleeb.ansari@gmail.com>

Picture Wall

2 messages

Maham Neha Ansari <maham.ansari.03@gmail.com> To: Salman Beg <salman.beg@akdn.org> Cc: Wajahat Ali <wajahat.ali@akdn.org>

Tue, Oct 4, 2016 at 7:31 PM

Dear Salman Sb, I hope you and the AKCSP team are doing well!

I'm now in the second week of my program! I have been asked to choose a building as a case study in terms of environmental/contextual performance and structural integrity, and study it throughout the term. Therefore, I have chosen to study the Picture Wall as it is an example of a nature and structural system.

I was wondering if I could please have permission to use the information/drawings of the Picture Wall that we have collected over the past year, for my research project?

Best Regards, Neha

Salman Beg <salman.beg@akdn.org> To: Maham Neha Ansari <maham.ansari.03@gmail.com> Cc: Wajahat Ali <wajahat.ali@akdn.org>

Tue, Oct 4, 2016 at 9:27 PM

Dear Neha,

Good to hear from you.

Yes, please go ahead and use – I am certain you will give due acknowledgement.

Wishing you the best.

Salman

From: maham.neha.andaleeb.ansari@gmail.com [mailto:maham.neha.andaleeb.ansari@gmail.com] On Behalf Of Maham Neha Ansari Sent: Tuesday, October 4, 2016 7:32 PM To: Salman Beg Cc: Wajahat Ali Subject: Picture Wall [Quoted text hidden]

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