ENERGY EFFICIENT HIGH-RISE BUILDINGS IN DIFFERENT CLIMATE REGIONS (RIYADH) Instructor: Dr-Ing. Mohannad Bayoumi
Eng. Abdulraheem Aalim
AR 408 Studio Design Department of Architecture Faculty of Architecture and Planning King Abdulaziz University
Students: Musaed Almutlak
Hashim Albar
02. LOCATION OVERVIEW & SELECTION 02.01 LOCATION OVERVIEW 02.02 SITE SELECTION & ANALYSIS 02.03 CLIMATE ANALYSIS 02.04 CASE STUDY
02.01 LOCATION OVERVIEW RIYADH Riyadh is the capital of Saudi Arabia and
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the largest city on the Arabian Peninsula. With a population of 6.9 million people, Riyadh is the third-largest city in the Arab world and the 39th-largest in Asia. Riyadh is located on the eastern part of the Najd plateau at about 600 metres (2,000 ft) above sea level, Riyadh is the political and administrative centre of Saudi Arabia and is the headquarters of the country's central government bodies.
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Covering 13.3 square kilometers on the grounds King Salman Park will be the largest urban park in the world, The master plan for King Salman Park calls for new mixed-use developments surrounding the central public open areas, coalescing into a dynamic and sustainable urban district that reflects the Kingdom’s Vision 2030 goals.
King Abdulah BD
King Salman Park
The King Abdullah Financial District (KAFD) is a new development under construction near King Fahad Road in Riyadh, Saudi Arabia. The project consists of 59 towers in an area of 1.6 million square meters. It will provide more than 3 million square meters of space for various uses.
Main Artery
Park
Metro
Airport
Main Roads
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02.01 LOCATION OVERVIEW LOCAL ARCHITECTURE The courtyard house or more strictly the atrium house, meaning a house with an internal courtyard open to the sky surrounded by rooms represents a commonsense response to the problems of a windy, dusty environment.
Airflow
Court
In the typical courtyard house, open space is closed entirely to nature at ground level, which is necessary to shelter from the heat and glare ... We also know, according to aerodynamics, that wind blowing above the house will not enter the courtyard, but will pass over and create eddies inside. Thus, the courtyard will retain the cool air that has settled there, and the air will seep into the rooms and walls, cooling the house.
a square central courtyard offers good protection from windblown dust and sand
Night: courtyard and roof act as cool air sink
Day: sun heats the courtyard, warm air rises creating chimney effect and pulls breeze through rooms.
Evening: courtyard and building retain heat then give it off as night air cools.
Downward air movement at base of main airflow caused by temperature difference between main airflow and palms: airflow eddies caused by contact with palm treetops allw dust particles to fall through foliage.
main airflow sand particles fall to ground
House, garden and courtyard from open area within palms: consequent exposure to sunlight and heat gives rise to upward air movement, pulling cooled air from palm grove through house.
Garden wall prevents remains of sand/dust penetraiting garden and house.
Facey, W., Charles, & Ibn Abd al-Aziz, Sultan ibn Salman . (2015). Back to earth: adobe building in Saudi Arabia. Riyadh: Al-Turath.
Airflow cooled by palm grove.
Sand and dust particles settle owing to reduced airflow speed.
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02.01 LOCATION OVERVIEW HIGH-RISE IN RIYADH The tallest building in Riyadh is the 385 meter super-tall skyscraper Capital Market Authority Tower. It is located in the new Skycraper hub, King Abdullah Financial District and is the 20th tallest Tower in the world.
Al Faisaliah Center King Fahad Road Construction Start 1997 Completion 2000 Floors 30
Kingdom Center Al-Urubah Road Construction Start 1999 Completion 2002 Floors 41
PIF Tower KAFD Construction Start 2010 Completion 2020 Floors 72
The skyline of Riyadh extended with the 310 metre tall Faisaliyah Tower which was completed in 2000. The Kingdom Centre built in 2002 overtook Faisaliyah Tower and now stands as the 4th tallest Tower in Riyadh at 312 meters. Riyadh is now the 3rd city in the Middle East after Dubai and Abu Dhabi. A total of 100 skyscrapers have been constructed since 2014 in the city.
http://www.skyscrapercenter.com/search riyadh
16
250
14
225
12
200
10
175
8
150
6
125
4
100
2
75
0
2022
275
2020
18
2018
300
2016
20
2014
325
2012
22
2010
350
2008
24
2006
375
2004
26
2002
400
2000
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No. of Buildings Completed (Bar)
Individual Building Height in Meters
The city is expected to reach on the Top 3 list of Skylines by the year 2020
425
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02.02 SITE SELECTION & ANALYSIS SITE 1
Plaza Public Library
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Site
Main Roads
Park
Metro
Commercial
Hotel
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02.02 SITE SELECTION & ANALYSIS SITE 2
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Main Roads
Park
Metro
Commercial
Hotel
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02.02 SITE SELECTION & ANALYSIS SITE 3
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Main Roads
Park
Metro
Commercial
Hotel
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02.02 SITE SELECTION & ANALYSIS SITE SELECTION CRITERIA Site 1
Area Near metro station Closer to CBD Mixed use & diversity Access to site
Site 2
Site 3
Site 1: 7850 m
Site 2: 18800 m
2
Site 3: 9030 m
2
2
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
0
1
2
3
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02.02 SITE SELECTION & ANALYSIS SITE LOCATION
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02.02 SITE SELECTION & ANALYSIS SITE CONTEXT
Site
King Fahad Road
Site
Commercial
Park
Hotel
Parking 11
02.02 SITE SELECTION & ANALYSIS ACCESSABILITY
Site
King Fahad Road
Site
One way road
Two way road 12
02.02 SITE SELECTION & ANALYSIS VIEWS
+ Site
Interesting views
Site 13
02.02 SITE SELECTION & ANALYSIS AREA & DIAMETERS
m 4 6
936
a: 7
Are 2
m
m
124
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02.03 CLIMATIC ANALYSIS RIYADH CLIMATE Temprature
Humidity
50
100
45
90
40
80
35
70
Relative humidity [%]
Ta - Outside air temperature [°C]
Riyadh is located on the eastern part of the Najd plateau at about 600 metres above sea level. Riyadh has a hot desert climate with long, extremely hot summers and short very mild winters. The average high temperature in August is 46.0 °C. The city experiences very little precipitation, especially in summer, but receives a fair amount of rain in March and April. It is also known to have dust storms during which the dust can be so thick that visibility is under 10 m .
Cooling
30 25
Comfort
20 15 10
Night cooling
1
2
3
4
5
6
7
8
9
Month max.
min.
10
11
Outside air temperature avg. min. max. Humidity avg. min. max. Wind velocity avg. wind velocity max. wind velocity
24.7 46.6
[°] [°]
26.7 5.0 46.0
[°C] [°C] [°C]
26.7 5.0 46.0
[%] [%] [%]
3.0 11.8
Global irradiation avg. radiation on horizontal surface max. Radiation on horizontal surface
[m/s] [m/s]
30° 40°
NNW NW WNW
W
0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0
60°
50
80°
40 30 17:09 pm
0
1
2
NNE
NNW NE
WSW
NW
ESE SW
SE SSW
SSE S
3
4
5
WNW
W
>10 m/s 8-10 m/s 6-8 m/s 4-6 m/s 2-4 m/s
Wind direction through out the year is from the north and the SSE.
6
7
8
9
Month Avg.
10
11
16% 14% 12% 10% 8% 6% 4% 2% 0%
6:33 am
12
max.
Drought through out the year especialy in hot months, evaporative cooling and vegetation could be used for humidification.
N
E
5:05 am
70°
min.
ENE
50°
18:45 pm
avg.
0-2 m/s
3.0 [m/s] 11.8 [m/s]
20°
60
12
subtropical arid Riyadh longitude latitude
10°
10
Difference in temprature at night and day wich gives potential for night cooling.
Climate
N
20
Night cooling
5 0
Sunpath
North elevation has the less amount of sunlight with the south has the most in winter were the maximun sun angle is 41.
N NNW
NNE
N NNE
20%
NW
NE
25%
NE
15% WNW
ENE
ENE
10% 5%
W
E
WSW
ESE SW
SE SSW
SSE S
>10 m/s 8-10 m/s 6-8 m/s 4-6 m/s 2-4 m/s 0-2 m/s
Wind direction in the summer is from the north.
E
0%
WSW
ESE SW
SE SSW
SSE S
>10 m/s 8-10 m/s 6-8 m/s 4-6 m/s 2-4 m/s 0-2 m/s
Wind direction in the winter is from the SSE.
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02.03 CLIMATIC ANALYSIS PSYCHROMETRIC CHART 100%
Yearly Hours in comfort zone = 37.6%
50%
Percentage
0.03
25
0.02
20
Wet-bulb (sling) o temperature, C 15
0.01 10 5
Acceptable
0 -10
Comfortable
Moisture content, kg/kg (dry air)
30
-5
0 -10
0
10
20
30
o
40
50
60
Dry-bulb temperature, C 0%
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02.03 CLIMATIC ANALYSIS PSYCHROMETRIC CHART 100%
Summer Hours in comfort zone = 8.7% Ta Enthalpy = 70-38 = 32 J/g 3 Enthalpy = 32/3.6x1.2 = 10.6 Wh/m
50%
Percentage
0.03
30
Te2 Enthalpy = 62-38 = 24 J/g 3 Enthalpy = 24/3.6x1.2 = 8 Wh/m
80 25
Energy Saved = 1-(8/10.6) Energy Saved = 24.5% 60
Ta = Outdoor Temperature Tr = Return air Temperature Te1 = Ta after exchanging with Tr Te2 = Te considering exchanger efficiency 70% 40
0.02
20
15 0.01
10 20 5 0 -10
Ta Comfortable
Acceptable
0 -5
Tr
Te1 Te2
0 -10
0
10
20
30
o
40
50
60
Dry-bulb temperature, C 0%
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02.03 CLIMATIC ANALYSIS PSYCHROMETRIC CHART 100%
Fall Hours in comfort zone = 51.6% Ta Enthalpy = 61-38 = 23 J/g 3 Enthalpy = 23/3.6x1.2 = 7.7 Wh/m
50%
Percentage
0.03
30
Te2 Enthalpy = 58-38 = 20 J/g 3 Enthalpy = 20/3.6x1.2 = 6.7 Wh/m
80
25
Energy Saved = 1-(6.7/7.7) Energy Saved = 13% 60
Ta = Outdoor Temperature Tr = Return air Temperature Te1 = Ta after exchanging with Tr Te2 = Te considering exchanger efficiency 70% 40
0.02
20
15 0.01
10 20
5 0
-10
Ta Comfortable
Acceptable
0 -5
Te1 Te2
Tr
-10
0
10
20
30
o
0 40
50
60
Dry-bulb temperature, C 0%
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02.03 CLIMATIC ANALYSIS PSYCHROMETRIC CHART 100%
Winter Hours in comfort zone = 43.3% Ta Enthalpy = 38-12 = 26 J/g 3 Enthalpy = 26/3.6x1.2 = 8.6 Wh/m
50%
Percentage
0.03
30
Te2 Enthalpy = 38-17 = 21 J/g 3 Enthalpy = 21/3.6x1.2 = 7 Wh/m
80
25
Energy Saved = 1-(7/8.6) Energy Saved = 18.6% 60
Ta = Outdoor Temperature Tr = Return air Temperature Te1 = Ta after exchanging with Tr Te2 = Te considering exchanger efficiency 90% 40
0.02
20
15 0.01 Comfortable
10 20
5 0
-10
Acceptable
0 -5 Ta Te2 Te1
-10
0
10
Tr
0 20
30
o
40
50
60
Dry-bulb temperature, C 0%
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02.03 CLIMATIC ANALYSIS PSYCHROMETRIC CHART 100%
Spring Hours in comfort zone = 31.4% Ta Enthalpy = 71-42 = 29 J/g 3 Enthalpy = 29/3.6x1.2 = 9.7 Wh/m
50%
Percentage
0.03
30
Te2 Enthalpy = 67-42 = 25 J/g 3 Enthalpy = 25/3.6x1.2 = 8.3 Wh/m
80
25
Energy Saved = 1-(8.3/9.7) Energy Saved = 14.4% 60
Ta = Outdoor Temperature Tr = Return air Temperature Te1 = Ta after exchanging with Tr Te2 = Te considering exchanger efficiency 70% 40
0.02
Tr
Te1 Te2
20
Ta
15
0.01 10
Comfortable
20
5 0
-10
Acceptable
0 -5
0 -10
0
10
20
30
o
40
50
60
Dry-bulb temperature, C 0%
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02.03 CLIMATIC ANALYSIS PSYCHROMETRIC CHART
Wh/m 3
Enthalpy
Enthalpy
12
30%
10
25%
8
20%
6
15%
4
10%
2
5%
0
0%
Summer
Fall Enthalpy
Winter Enthalpy after heat exchange
Spring
Summer
Fall
Winter
Spring
Enthalpy after heat exchange
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02.04 CASE STUDY COMMERZBANK Year: 1991-1997 Storeys: 53 Height: 298m Capacity: 2400 Natural Ventilation Strategy: Cross and Stack Ventilation Design Strategies: 1- Double Skin Facade. 2- Sky Garden connected by segmented central atrium.
Passive Design
Form and Massing
Wellbeing
The building was designed to be naturally ventilated for 60% of the year, with the sky gardens allowing natural ventilation during shoulder seasons. This approach was expected to reduce energy consumption by up to 50% compared to an equivalent air conditioned office.
The triangular shape and central atrium assisted in the creation of a zone of negative pressure, that drives natural ventilation through the building.
Designed with the end user in mind, office areas are naturally ventilated and flooded with daylight. Users can regulate their own environments and sky gardens act as a breakout space.
www.fosterandpartners.com, F. P. /. (n.d.). Commerzbank Headquarters: Foster Partners. Retrieved from https://www.fosterandpartners.com/projects/commerzbank-headquarters/
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02.04 CASE STUDY COMMERZBANK Structure System
Environmental Systems
Double Skin Facade
Performance in Use
Virendeel Beam
Passive
Active First skyscraper in Germany to incorporate steel as its main structural component, Standardized 8 story Virendeel truss system, To support weight of steel, three mega columns consisting of H-framed steel columns with diagonal bracings encased in concrete were used on the vertices of the triangular plan.
Cooling is provided by chilled ceilings, while heating is from perimeter heating. Windows are connected to the BMS to ensure that the mechanical ventilation only works when the windows are closed. Artificial lighting is connected to motion sensors and timers.
Cooling is provided by chilled ceilings, while heating is from perimeter heating. Windows are connected to the BMS to ensure that the mechanical ventilation only works when the windows are closed. Artificial lighting is connected to motion sensors and timers.
www.fosterandpartners.com, F. P. /. (n.d.). Commerzbank Headquarters: Foster Partners. Retrieved from https://www.fosterandpartners.com/projects/commerzbank-headquarters/
Post occupancy studies have shown that the tower actually consumes 20% less energy than predicted, and there has been a year on year reduction in energy consumption since 2000. This is largely because the building users have extended the period of natural ventilation up to 85% of the year, as opposed to the 60% designed for.
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03. DESIGN APPROACH 03.01 FORM FINDING 03.02 DESIGN STRATGIES 03.03 DESIGN CRITERIA
03.01 FORM FINDING CFD ( RECTANGLE ) Hight = 10m
Hight = 50m
Hight = 90m
Wind direction
Wind direction
Wind direction
Wind direction
Wind direction
Wind direction
Cp = 0.39 3 Q = 1.2 m/s 3 Q = 4412 m/h
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03.01 FORM FINDING CFD ( SQUARE ) Hight = 10m
Hight = 50m
Hight = 90m
Wind direction
Wind direction
Wind direction
Wind direction
Cp = 0.38 3 Q = 1.2 m/s 3 Q = 4327.4 m/h
Wind direction
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03.01 FORM FINDING CFD ( TRIANGLE ) Hight = 10m
Hight = 50m
Hight = 90m
Wind direction
Wind direction
Wind direction
Wind direction
Wind direction
Wind direction
Cp = 0.33 3 Q = 1.1 m/s 3 Q = 4032.7 m/h
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03.01 FORM FINDING SOLAR RADIATION ANALYSIS ( SQUARE ) 21 JUN 8:00 am - 20 SEP 16:00 pm N
2
kWh/m
10°
616.7
20° 30°
555.04
40° 50°
18:45 pm
5:05 am
60° 16:00 pm
70° 80°
493.37 431.70
08:00 am
370.02 308.35 16:00 pm
08:00 am
17:09 pm
246.68 6:33 am
16:00 pm
08:00 am
185.01 123.34 61.67 0.00
West Elv.
East Elv.
North Elv.
South Elv.
West Elv.
East Elv.
North Elv.
South Elv.
21 JUN 8:00 am - 20 SEP 16:00 pm 2
kWh/m 415.37 373.84 332.30 290.76 249.22 207.69 166.15 124.61 83.07 41.54 0.00
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03.01 FORM FINDING SOLAR RADIATION ANALYSIS ( RECTANGLE ) 21 JUN 8:00 am - 20 SEP 16:00 pm N
2
kWh/m
10°
616.7
20° 30°
555.04
40° 50°
18:45 pm
5:05 am
60° 16:00 pm
70° 80°
493.37 431.70
08:00 am
370.02 308.35 16:00 pm
08:00 am
17:09 pm
246.68 6:33 am
16:00 pm
08:00 am
185.01 123.34 61.67 0.00
West Elv.
East Elv.
North Elv.
South Elv.
West Elv.
East Elv.
North Elv.
South Elv.
21 JUN 8:00 am - 20 SEP 16:00 pm 2
kWh/m 415.37 373.84 332.30 290.76 249.22 207.69 166.15 124.61 83.07 41.54 0.00
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03.01 FORM FINDING SOLAR RADIATION ANALYSIS ( TRIANGLE ) N
2
kWh/m
10°
616.7
20° 30°
555.04
40° 50°
18:45 pm
5:05 am
60° 16:00 pm
70° 80°
493.37 431.70
08:00 am
370.02 308.35 16:00 pm
08:00 am
17:09 pm
246.68 6:33 am
16:00 pm
08:00 am
185.01 123.34 61.67 0.00
West Elv.
East Elv.
South Elv.
West Elv.
East Elv.
South Elv.
2
kWh/m 415.37 373.84 332.30 290.76 249.22 207.69 166.15 124.61 83.07 41.54 0.00
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03.01 FORM FINDING COOLING LOAD ANALYSIS 70
2
Cooling demand (kWh/m.a)
60 50 A
40
B
30 C
20
D
10 0 Core in the middle
Core on the sides
Square
Core in the middle
Core on the sides
Rectangle
Core in the middle
Core on the sides
Triangle
A B
C D
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03.01 FORM FINDING FORM COMPARSION
CFDWind velocity
+
CFD-cP
Solar radiation
IDACooling load
- --
Cp = 0.38 3
Q = 1.2 m/s 3 Q = 4327.4 m/h
+ - -
2
+
3
Q = 1.2 m/s 3 Q = 4412.4 m/h
2
Roof area = 900 m 2 Solar radiation = 373.84 kWh/m 900 x 373.84 = 336456 kWh
Cooling load in relation to form orientation & core positioning
Cp = 0.39
Roof area = 1800 m 2 Solar radiation = 373.84 kWh/m 1800 x 373.84 = 672912 kWh
Cooling load in relation to form orientation & core positioning
+
+ - -
Cp = 0.33 3
Q = 1.1 m/s 3 Q = 4032.7 m/h
2
Roof area = 670 m 2 Solar radiation = 373.84 kWh/m 670 x 373.84 = 250472 kWh
Cooling load in relation to form orientation & core positioning
+
Site views
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03.02 DESIGN STRATGIES CLIMATIC STRATGIES
Stack ventilation
Night cooling
Segmentation
Evaporation on green
Introducing segementation can alleviat air flow in the building.
Air cooled by vegitation.
Tm
Unsegmented tall building creats estreme stack flows.
Building gives off heat at night.
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03.02 DESIGN STRATGIES SITE SOLUTION
Lobby
Lobby
Summer hot wind.
Main entrance
Eight story building casts shadow on site. No potential for views and main entrance. Road can be used for acces to parking.
Main entrance
Winter wind.
Parking building separated Pros: -Different structural tructure module -Lobby connected to plaza -Horizontal plane can be used for PV Cons: -Blocks south winds
Podium Pros: -Lobby closer to higher wind speeds Plaza on the north part of the site, vegetation on plaza cools & humidifys summer wind.
Lobby
Road on the south could be used for access to parking.
Cons: -Less space for PV -Lobby not connected with plaza -Structural module complications
Underground parking Pros: -Lobby closer to higher wind speeds
Lobby
Cons: -Higher cost -Less space for thermal labyrinth -Structural module complications
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03.02 DESIGN STRATGIES CORE ORGANIZATION
Central core
Large space for offices.
Less space for atrium.
75% exposure to solar radiation.
Blocks ventilation.
75% sunlight.
Less space for offices
Space for atrium.
25% exposure to solar radiation.
Cross ventilation.
25% sunlight.
Two elevations open to views.
Space for atrium.
Less exposure to radiation.
70% sunlight.
Views on all elevations
360 views.
Cores on sides
Cores on the corners
Space for offices on all sides.
Cross ventilation.
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03.03 DESIGN CRITERIA
Flexable plan
Less solar radiation
Views, Ventilation & Daylight
Reducing amount of hard light that enters the building.
Atrium for ventilation and daylight and sky gardens for providing views.
Green House Effect
Office Space
Office Space
Office Space
Preconditioning wind
Office Space
Office Space
Office Space
Providing fexable office plans with a veriaty of office types.
Preconditioning wind before entering the building either by using dubble skin facade system or vegitation.
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