Las Vegas: Sunshyne

Las Vegas: Sunshyne Gebäudetechnologie und klimagerechtes Entwerfen / Climate Responsive Design / Sustainable Architecture Verónica Aguirre Alexis Escalante Martin Valinger Sluga Marija Vitkauskaite WS 2018 Prof. M. Rudolph, AM C. Degenhardt ABK Stuttgart IUSD - Universität Stuttgart

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Las Vegas: Sunshyne “The Interview” What makes your project unique?

Due to its ability to respond to harsh conditions of desert climate while being energy efficient, “Sunshyne” (name is coined from words “sunshine” and “shy”, “meaning being shy of sunshine”) is a unique example of sustainable mixed-use, high-density urban block in the middle of one of the most unsustainable urban agglomerations in the world. Therefore, it serves as a case study in changing the development and design trends and excessive consumption of energy and water. Using mainly climate-responsive passive design strategies, it tackles multiple environmental challenges at once to achieve maximum climate comfort of individuals and integrates renewable energy sources.

What does your project bring to the community?

“Sunshyne”, in contrast to other urban areas in the city, brings its residents and visitors a unique chance to experience a vibrant space and diverse program not just indoors but also outdoors. Apart from offering them many attractive uses it serves as shaded and ventilated “oasis” in the middle of the overheated artificial urban landscape.

The concept of design provides a strong argument against the use of energy-wasting and inefficient ways for achieving climate comfort (such as air-conditioning) which are co-creating negative environmental consequences (i.e. urban heat island).

What are the key features of your project design, which embodies and strengthen the local identity?

Apart from offering the activities which promotes participation in the lively public and cultural life, the key feature of “Sunshyne” is the ability to provide natural shading and climate comfort indoor and outdoor all year round.

At the same time, sun is also considered as a main energetic potential, providing a clean and reusable supply of energy. Open spaces inside the urban block are narrow and shaded, resembling a characteristic natural feature of surrounding desert - canyon. Supporting material - hempcrete - is a bio-composite mixture of hemp hurds and lime, production

of which boosts the local hemp economy and raises the awareness of hemp applicability. North of the urban block, a desert-like landscape park is designed using drought-tolerant desert vegetation.

Apart from serving as interesting and visually pleasant space right next to the designed urban block it raises awareness of water stewardship in the city.

How would you like the occupants to feel?

As mentioned before, “Sunshyne” provides climate comfort to its residents and visitors in all seasons.

In the summer, it protects them from the extensive solar radiation, high temperatures and hot wind, providing thick shadows and pleasant ventilation. In the winter, it protects them from lower temperatures by storing heat and radiating it back outdoors, and breaking down cool winds.

Why would people enjoy your buildings?

Aditionally to climate comfort, “Sunshyne” gives its visitors a chance to participate in diverse public, cultural and commercial program with amenities such as the library, community center, theater, shopping mall, casino, hotel etc. These are connected through a series of bridges/skywalks and a raised public area, creating a large and attractive open space. The ground floor is also used for commercial purposes, offering visitors a wide selection of shops, services, bars, restaurants and other places of interaction.

Which indoor and outdoor place is your favourite in your design and why?

Our favourite outdoor spaces are the „urban canyons“, resembling a recognizable feature of

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

the desert landscape, combining the measures to achieve climate comfort and offering the diverse program. One of the most interesting and unique places in our urban block is also the raised public area in the southernmost building, serving as both outdoor (summer) and indoor space (winter). This adaptation is allowed by flexible facade technology which is responding accordingly to current climate conditions. Our favourite indoor spaces are the duplex apartments in the northern buildings of the urban block. This is due to several reasons, first one being the location next to the landscape park and the river, providing excellent views on the surroundings. Additionally, they allow effective illumination throughout the year, pleasant crossventilation of interiors and spaces with double height ceiling.

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Las Vegas: Sunshyne Location: Las Vegas, Nevada, USA 36°10’30’’N, 115°08’11’’W / alt. 610m Located in Las Vegas Valley, 1600km² tectonic basin area in Mojave Desert surrounded by mountain ranges on all sides. The highest nearby elevation is Mt Charleston (3633m) City area: 352 km² / 623 912 / 1772 ppl per km² Metropolitan area: 2 036 338 (2016 est.)

Climate: Hot and arid (Desert climate) Las Vegas (meaning “meadows” in Spanish) is a town that literally appears from nowhere.

Contrary to the historic landscape, which was covered by numerous artesian wells surrounded by extensive green areas, much of the landscape nowadays is rocky with desert vegetation and wildlife. The peaks surrounding Las Vegas (Figure 1) act as barriers to the strong flow of moisture from the surrounding areas, what normally produces a rain shadow.

Although it sits above North America’s largest water shed, Great Basin, most of the water makes its way into what is known as a “basinfill aquifer”. These water sources which exist at about 200–300m underground became, together with surface waters such as artificial Lake Mead (Figure 4), heavily depleted throughout the history. Extensive groundwater withdrawals and rapid urban growth in the second half of 20th century, also resulted in land subsidence and drought. On top of that, heat waves had been very common in the last few years, smashing the temperature records which consequently closing the schools, grounding the flights and also resulting to the death of people. In 2017, the highest temperature since 1942 was recorded at 47,2°C. Like many other fast growing Amerian West cities, mainly focusing on profit returns from rich industries such as mining, gambling and tourism, Las Vegas repeatedly failed to attend the above mentioned environmental issues. Instead of that, the city continued to sprawl, creating a seemingly endless singlehouse, low-dense suburbia (Figures 2 and 3).

Furthermore, the citizens continued to rely on individual transportation and energy-wasteful

technologies in order to sustain this kind of destructive urban development. The rapid development and population growth both halted abruptly in the late 2000s when the US housing market crashed. That being said, after the atrocities of mentioned urban development were finally exposed, the moment to think and act differently is now.

“Sunshyne” is a mixed-use, high-dense urban block, following the guidelines of climate-responsive design. Based mainly on passive design strategies, it tries to tackle multiple environmental challenges at once in order to achieve maximum climate comfort of its inhabitants. By integrating renewable energy sources, it works as a case study in changing the design trends in the city and achieving a more sustainably oriented urban development.

FIGURE 1: URBAN AREA AND SURROUNDINGS

FIGURE 2: VIEW ON THE CITY CENTRE

FIGURE 3: URBAN SPRAWL

FIGURE 4: LAKE MEAD

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

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Climate analysis

FIGURE 5: DESERT CLIMATE OF SOUTHWEST US

FIGURE 6: MOJAVE DESERT

FIGURE 7: SOLAR IRRADIATION

FIGURE8: AVERAGE HIGH AND LOW TEMPERATURES

FIGURE 9: HUMIDITY

FIGURE 10: SUN PATH

FIGURE 11: AVERAGE HOURLY TEMPERATURE

FIGURE 12: WIND DIRECTION AND SPEED

FIGURE 13: CLOUD COVERAGE

FIGURE 14: AVERAGE MONTHLY RAINFALL

Desert climate of Southwest US Located in Mojave Desert (Figure 6) in the desert climate of American southwest (Figure 5), Las Vegas is known for its hot and arid climate. In terms of solar irradiation, the yearly average Global Horizontal index scores 2076 KWh/m2. Under the shadows of buildings, the diffuse horizontal (DIF) scores 474 KwH/m.

(Figure 7) The highest number rates of sun elevation occurs at 12:00. This number varies at the same hour in each different day, decreasing as it gets to the winter and increasing as it comes to the summer. Contrary to the sun elevation, the azimut grades behave in a diferently because of being a reference of where the position of the sun is in a horizontal and round path of the sun. (Figure 10) Even though the temperatures are already high in the spring, the hot season begins in June and lasts until mid-September, reaching 40ºC and more. Although it can get quite cold, the winter is relatively short. The lowest temperatures during the day are around 6º to 13º. (Figure 8) Change of temperature between seasons and day-night is quite drastic. High temperatures during a common day in the most part of the summer are what defines this season as hot and often even sweltering. In this period, even the morning temperatures are 20-27ºC. In the winter, the most recognizable characteristics are cold nights, typical for desert climate.

(Figure 11) As mentioned before solar irradiation levels are very high. This is also due to the lack of cloud presence during the most time of the year. Cloudier parts of the year are in the winter, corresponding to the lower temperatures and increased chances of precipitation. (Figure 13) Las Vegas is well sheltered from moisture, allowing the city to experience very low levels of humidity. Therefore, the perceived humidity level in Las Vegas is mostly dry. Humidity comfort level is muggy, oppressive, or miserable less than 2% of the year. (Figure 9) The wind in Las Vegas is present throughout of the year, blowing slowly but in relatively steady fashion.

The windiest part of the year is from March to July. Calmer times of the year last for 8 months, from July to March. The wind blowing from SE is blowing during the summer, making it very hot and less pleasant. The wind coming from NW is blowing for 6 months and is pleasant. (Figure 12)

The presence of rain in the south of Nevada is pretty low. Notwithstanding that winter is a bit rainier than summer, stormy weather is likely to happen, due to a seasonal phenomenon coming from the major mountain ranges in the north of Mexico, better known as the Arizona Monsoon, an increasing pattern of thunderstorms and rainfall during the afternoons.

(Figure 13)

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

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Vernacular architecture Vernacular architecture from the area is analysed to get a better picture on how people used to respond to harsh climatic conditions without the use of modern technology. Although originating from different historical periods, all the examples of vernacular architecture were following similar design approaches, mainly responding to solar radiation, high temperatures and hot winds.

Wickiup (Figure 15) was a shelter regularly built by the Southern Paiutes, a nomad tribe which settled in the area of modern Las Vegas around AD 700. Adjusting accordingly to the climate, tribe regularly migrated between nearby mountaines in the summer and spending winter in the valley. Wickiup was a simple semipermanent home, small and round to minimize heat loose and dome shaped to avoid direct sunlight to the facade. They were built 30-60cm in the ground to use the the benefits of thermal inertia. (Figure 21) After the Mormon Church settled in Las Vegas area, it built a first permanent structure to convert the nomadic Southern Paiutes to Mormonism and teach them new farming techniques. After the mission was closed, the Old Las Vegas Mormon Fort (Figure 16) served as a ranch, resort, and cement testing facility.

The fort was made of thick walls of adobe bricks with several subdivisions of interior and a courtyard in the northern part of the parcel.

(Figure 22) The settlers diverted water from the creek to irrigate farmland. However, crop failures caused the settlers to abandon the fort in March of 1857.

Pueblo Taos in New Mexico (Figure 17) is an example of multistored, attached homes.

Eventhough not all the aspects of climate are relevant for Las Vegas, this example provides several methods and techniques used in the given climate. The nuclearly arranged houses were built very close together and stacked five or six stories high. (Figure 20) The homes became narrower as they rose, with the roofs of each level providing the floors and terraces for those above, giving the building resemblence of a stepped pyramid. Traditional pueblo construction used limestone blocks or large adobe bricks. In a typical pueblo building, adobe blocks form the walls of each room as well as a central courtyard.

FIGURE 15: WICKIUP (SOUTH PAUITES)

FIGURE 16: OLD MORMON FORT

FIGURE 17: PUEBLO TAOS

FIGURE 18: STRUCTURE OF WICKIUP

FIGURE 19: SITE PLAN OF OLD MORMON FORT

FIGURE 20: CLUSTERED BUILDING BLOCKS IN PUEBLO TAOS

Process of construction (Figure 18): A flat land was selected and cleared of brush and a circle was traced indicating the position. The poles were placed firmly in the holes and then bent in an arch to form the dome shape. The poles of the frame was lashed together with tough yucca fibers and bound together at the top.

The fort was made of adobe bricks and, when completed, consisted of four walls 150 feet long, two bastions and a row of two-story interior buildings.

(Figure 19) Parts of the original eastern wall and the southeast bastion remain preserved on the site today in the middle of Las Vegas.

The most interesting strategy used were thick walls and the heat and air ventilation system. Together they prevented the heating of the interior during the hot summer days but also store the heat for cold winter nights. (Figure 23)

FIGURE 21: PASSIVE DESIGN STRATEGIES (WICKIUP)

FIGURE 22: PASSIVE DESIGN STRATEGIES (OLD MORMON FORT)

FIGURE 23: PASSIVE DESIGN STRATEGIES (PUEBLO TAOS)

Round shape

Compact form

Thermal inertia

Thick walls

Minimum openings

Insulation

Courtyards towards north

Subdivision of interior

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

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Passive design strategies Based on the environmental research of the location and climate analysis, it is clear that there are three major climatic challenges to address in Las Vegas in order to create a climate-responsive urban block: (1) extensive solar radiation and high temperatures (especially in the summer), (2) hot winds from the south in the summer and (3) low levels of precipitation and water shortage.

This means that design has to first respond to each of those separately, before tackling all the problems together. That being said, three prototypes using solely passive design strategies were created, each of them focusing on a specific climatic challenge. (Figures 24, 25 and 26) Although all three challenges (sun, wind, water) require appropriate strategies, creating a prototype which is adequately responding to high temperatures and is minimizing solar gains (sun prototype), is a clear priority. In this prototype, buildings are only slightly separated each other and differ in height in order to shade each other as much as possibly and to create shaded courtyards. Larger facades are facing north and south in order to avoid the direct sunlight from east and west. Ground floor is shaded by arcades. High density materials (walls) are used to prevent the heat from entering during the day and releasing the caught heat during the night. The window openings cover less than the 10% of the surface to avoid overheating of interior. The natural light is reflected by reflective surfaces to avoid the absorption of heat.

The wind prototype is mainly focusing on blocking the hot winds from the south. The more pleasant wind from the north is tolerated to some extent, by deviating it through gradual increase of building heights. The water prototype was primarily focusing on water stewardship, so reuse of rainwater and recharge groundwater recharge was a top priority.

After creating three prototypes, each of them corresponding to one of the major climatic challenges, the success of designs is analysed.

Based on this analysis the most successful passive design strategies from each of the prototypes are extracted and merged together in order to get a comprehensive toolbox of passive design strategies for Las Vegas climate.

FIGURE 24: SUN PROTOYPE

FIGURE 25: WIND PROTOTYPE

FIGURE 26: WATER PROTOTYPE

FIGURE 27: PASSIVE DESIGN STRATEGIES (URBAN SCALE) N

Maximum shading (density)

N

Maximizing N & S facades, minimizing W & E facades

N

N

N

Roof inclination (max. north facing facades)

Blocking hot wind, breaking cool wind

Gradual height growth to deviate wind

Courtyards with water elements (cooling and humidifying)

Minimum window openings on W and E facades

Additional shading elements

Controlling ventilation (openings and wind cowls)

Rainwater reuse and groundwater recharge

FIGURE 28: PASSIVE DESIGN STRATEGIES (BUILDING SCALE) summer

winter

Thermal mass and maximum emissivity

Shaded arcades

FIGURE 29: OTHER STRATEGIES

(Figures 27, 28 and 29) Since sun is the most challenging climate characteristic, toolbox prioritizes it by mainly introducing several strategies to mitigate its effects and create climate comfort. Wind strategies are also present, while water strategies serve more as supporting aspect and are mostly composed of active strategies.

Thermal inertia

Solar photovoltaic technology

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

Xeriscaping

Designing the urban block

FIGURE 30

The next step is to design a mixed-use urban block which respons to existing climate challenges with the goal to help Las Vegas becoming more liveable and sustainable urban area. The process of design starts off N with understanding of solar radiation and high temperatures as the biggest challenge to Occupying maximum coverage of the plot address, therefore prioritizing the responses accordingly and defining the architecture the FIGURE 33 most. Wind is understood as main supporting aspect and water as less important but still acknowledgable aspect.

To start off, the volume of an urban block is occupying the whole plot in order to achieve maximum coverage, hence protection from the solar radiation (Figure 30). To achieve optimal sun orientation in the winter the building block is tilted for 25° to the east. (Figure 31) The shape of the urban block initially corresponds to the hot summer wind from the southeast direction, N blocking it as much possible. (Figure 32) In the next step, north and south facing facades are maximized while west and east facing are Exposing north and south, minimizing west and east facades minimized in order prevent extensive solar radiation. (Figure 33) Wind from the north is cooler FIGURE 36 and more pleasant, therefore the design allows it to penetrate inside the block. (Figure 34) However, to avoid too much ventilation, the buildings are moved in W-E direction to break the wind (Figure 35) and later gradually raised to deviate it. (Figure 36) In the next step, three objects are merged into a Z-shaped volume which continues to block the wind but also allows the implementation of large open space in the ground floor, serving as a vibrant meeting place of local community and visitors of the area. (Figure 37) N To achieve maximum shading of the urban block, the western part of the southernmost building Gradually increasing height to deviate cool wind is raised as much as possible. (Figure 38) At the same time, this opens up even more north facing FIGURE 39 facades. To shade the ground floor even better, series of bridges/skywalks are implemented which at the same time serve as communication channels between commercial, cultural and public uses between the buildings. (Figure 39) Together with this step, a large raised public area is opened up in the fourth and fifth floor. The opening plays many roles, from being an adaptive public space that can offer visitors climate comfort all year round to cooling off the hot wind and controlling the ventilation inside the urban block. Aditionally, ground floor becomes self-shaded by the N implementation of arcades. (Figure 40) Lastly, to open up the north facades even more, roofs are slightly inclined towards the south in order to allow Skywalks, shaded arcades and raised public area maximum illumination. (Figure 41)

FIGURE 31

FIGURE 32

N

N

Blocking hot wind from the south

Optimal orientation for winter sun (25° to E) FIGURE 34

FIGURE 35

N

N

Breaking the cool wind

Allowing cool wind from north to enter FIGURE 37

FIGURE 38

N

N

Blocking the cool wind, opening the ground floor level FIGURE 40

Increasing height for shading purposes FIGURE 41

N

N

Self-shading facade elements

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

Inclining the roofs to maximize north facing facades

Testing the urban block

FIGURES 42-47: SHADING ANALYSIS

with Transolar Academy fellows To test how climate-responsive the designed urban block is, fellows from Transolar Academy used the necessary tools and methods to test ability of the desing to respond to the given climate. The most concerning issue at this stage is the lack of daylight due to increased focus on protection of the buildings and interiors from extensive solar radiation. Hence, the following question was raised in order for the fellows to run simulations and analyse the success of proposed measures. Some of the analyses are included below (solar radiation (Figure 48) and illumination (Figure 49). Design and program is later adapted accordingly to respond to given climatic challenges even better. (Figure 50)

Summer

10:00

12:00

15:00

10:00

12:00

15:00

For more information about presented analysis see Appendix.

Q: Sunlight-daylight ratio Situation: Protection of buildings and the open space from the extensive solar radiation is a priority.

Therefore we are trying to shade as much of the massing and open space with the position, orientation and the shape of the buildings themselves. (Figures 42-47) Problem: Winter

FIGURE 48: SOLAR RADIATION ANALYSIS

FIGURE 49: ILLUMINATION ANALYSIS

Question:

%

: 20

glz

%

l

nt ide

d

si Re

%

30

s Re

20%

l

Residential: 150 lx/m2

%

30

ntia

de

si Re

%

30 %

30

/ blic Pu tural l u c

%

4

%

45

% 30

30%

tel

Ho

20%

40

0%

/ blic Pu tural cul

/ blic Pu tural l u c 00lx/m 2

5

% 20

%

40

ial

20

ia ent

% 40

2nd floor

Illumination standards:

10%

Subquestion: How can we adapt the buildings and the open space and which techniques could we use to receive more sunlight and daylight in the wintertime?

ground floor

FIGURE 50: ILLUMINATION GUIDELINES FOR PROGRAM

35%

What is the most adequate ratio between providing enough illumination for indoor spaces and protecting the interiors and groundfloor open spaces from sun?

Goal: Allow at least 150 lx/m2 coming to the interiors with glazing of buildings being 25%

10%

Goal: Decrease unobstructed radiation by 70% (600 kWh/m2 to 180 kWh/m2)

% 20

However, we also realized that our proposal needs to provide enough daylight for the interiors. Apart from increasing the amount of north facing facades, adapting the program and providing seasonal shading, we would still need advice on what is the most appropriate relationship between shading and allowing solar gains.

Cultural/Public: 500 lx/m2 Commercial/Offices: 500 lx/m2 Hotel: 150 lx/m2

%

45

%

45

/ ial erc mm ices o C Off %

40

%

30

Glazing (glz) by facades: North: 20 - 40% South: 30 - 45% East: 10 - 20%

Ground floor 21.6. - 21.9.

8:00 - 18.00

West: 0 - 10% 3rd floor

5th floor

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

Climate concept After testing the urban block and analysing the viability of passive and active design strategies in achieving climate comfort, the design of the urban block is adequately modified.

To present the impact of applied strategies in a compact and comprehensive matter, climate, comfort and energy concept diagram is derived.

(Figure 51) Starting off with the strategies which are responding to extenstive solar radiation, several shading strategies are implemented. To avoid direct sunlight and avoid glare in the interiors, lightshelves are introduced along the southern facades. On the hotel building, the facade is gradually retired to create self-shading effect.

Adaptive shading facade elements that cover raised public area in the southernmost object, have multiple roles. Firstly, they redirect sunlight in the summer, while allowing diffused daylight to illuminate the space. In the winter (if needed), they can redirect solar gains towards interior to warm up the shaded area. Secondly, they control the amount of hot wind allowed inside the urban block. Some part of the hot wind is deviated in the upper level of the opening towards exit, while the rest of it is cooled down by dry mist and redirected towards the public spaces in groundfloor to ventilate them adequately.

In the ground floor, shaded arcades which allow pleasant moving of pedestrians in the shadow, are realized. Seasonal shading is introduced in less protected and most busy open spaces to enable the use of these public areas all year round. Other shading elements include self-shaded facade elements on the north facades of the residential buildings, which make sure that the apartments are protected from sunlight in from east and west. The buildings are gradually raised towards the south for two reasons, the first one being to deviate the cool wind and create slight wind turbines which help ventilate the narrow corridors between the buildings. The other reason is to cast more shadow on other buildings. The roofs of buildings are inclined to expose the northern facades as much as possible to provide maximum illumination of interiors.

FIGURE 51: CLIMATE, COMFORT AND ENERGY CONCEPT

Wind cowls

Indirect sunlight

Introducing cool air Indoor ventilation

Self-shading facade Releasing warm air

Summer

Exposed northern facades (max. illumination)

Redirecting sunlight, allowing diffused daylight

Rainwater catching

Photovoltaic panels

Winter

Water tanks Deviating cool wind

Solar energy for hot water

Adaptive facade

Cooling down wind

Greywater reuse

Controlling ventilation (raised public area opening)

Ventilation turbine

Shading elements elements (W-E)

Seasonal shading Xeriscaping

Shaded arcades

Rainwater reuse

Dry mist

Rain/greywater treatment station

Thermal inertia

Water treatment cycle

On some roofs, wind cowls are located to additionally ventilate the interior of the buildings. Wind cowls have dual effect, as they release/suck out warm air and introduce cool air at the same time. Another roof element are the rainwater catchers, running the rainwater underground where it is purified in the treatment station along with greywater. This water is later used to humidify the outdoors thorugh dry mist sprinkles. Photovoltaic panels are the third roof elements, providing the buildings with clean and reusable energy.

Solar energy for public lightining

N Solar energy station

Energy treatment cycle

Although the sun presents major climate challenge in Las Vegas, it also presents the main energy potential/ resource. Photovoltaic panels and solar water heaters are therefore placed on the most exposed roofs.

(Figure 52) The solar energy is used to enlighten the public spaces and provides households with cheap warm water.

Las Vegas is a desert city that carelessly uses limited water resources it does not have, therefore “Sunshyne” aims to collect and safe as much water as possible.

(Figure 53) Scarce rainwater is collected, purified and reused to humidify the open spaces. Greywater is also treated and reused. Water-saving appliances, such as dual flush toilets, are taken for granted.

FIGURE 52: SOLAR ENERGY

FIGURE 53: WATER REUSE

Other strategies include the introduction of underground areas, goal of which is to use the benefits of thermal inertia and xeriscaping, to create a a desert-like landscape park north of the urban block site.

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

Distribution of program The distribution of the program corresponds to the rhythm of life in Las Vegas. The project seeks to be functional 24/7, so that greater emphasis is placed on public areas and commercial use. Basically, the proposal is divided into 4 pillars: Hotel, offices / commerce, cultural / public and residential. (Figure 54) Towards the south the highest and with more character building volumes are placed since they will welcome to the user: the hotel and offices, whereas towards the interior there are spaces destined for more public practices to invite users to enter the complex and to cross it freely, finally, the residential area obtain the preferential location, towards the north, to avoid the direct solar exposure and achieve a suitable xeriscape view.

FIGURE 54: DISTRIBUTION OF PROGRAM IN BUILDINGS

Residential

Hotel Cultural/Public Spa

Food court

Commercial

Pool Auditorium Sport Center

Conference room Offices

Restaurant Exhibition

There are two levels of public use to dynamize the proposal: On the first level is the public outdoor space that connects the restaurants, commerce, reception, casino and playground through streets and squares that recall the desert canyons. In the fourth and fifth levels there is an elevated public area that unifies the higher common uses such as food court, media library, library, sport center, auditorium, among others, and serves as an excuse to add bridges on both levels as an architectural and climatic gesture. (Figure 55)

Administration Library Food court Retail

Media Library

Multipurpose room Casino

Housing Playground Multipurpose area

URBAN INDICATORS Plot area: 10,000 m 2 Built-up area: 5,,728 m 2 Setbback area: 4271 m 2 Floor area: 45,502 m 2 Max. Height: GF+14 Height index: 7.98 FAR: 4.55 COV: 0.57

Housing Playground

PERCENTAGE OF PROGRAMS Hotel: 15,674 m 2 34.44% Offices: 3,540 m 2 7.77% Commercial: 7,522 m 2 16.53% Residential: 9,806 m 2 21.55% Cultural/Public: 8,960 m 2 19.69% Constructed area: 45,502 m 2 100%

Hotel

FIGURE 55: PROGRAM ZONING SECTION

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

Indoor comfort and high-tech solutions Ground floor The ground floor is shaded most of the time. This is because all the facades at this level are retired from the edge of the building (Figure 56), allowing for better ventilated wider streets and continous connection between program in the ground floor and open spaces. Seasonal shading is introduced where solar gains are impossible to prevent with passive shading. The cover adapts to the giving season (Figures 59 and 62) by opening and closing of the shading panels and contains dry mist sprinklers.

Residential buildings It is of great importance, to provide crossventilation in every apartment and to maximaze the use of the space. The introduced typology is therefore the duplex apartment. (Figure 60) The south facade is protected by lightshelves which can be easily adapted by the user to allow a desired amount of received sunlight and daylight. (Figure 57) The north facades are shaded using different shading facade elements, mostly preventing the sun from west and east but allowing sufficient amounts of diffused daylight.

Public/cultural buildings The three central buildings, fostering public and cultural program (Figure 58) aim to connect all the public uses and floors with the central raised public area/opening which at the same time works as a light reflecting space and hot wind cooler.

The south facade is protected by flexible shading technologies. Shading panels can be regualted to allow or redirect sunlight.

Hotel building

FIGURE 56: GROUND FLOOR PUBLIC SPACES

FIGURE 57: RESIDENTIAL BUILDINGS

FIGURE 58: PUBLIC/CULTURAL BUILDINGS SECTION A-A

SW

Cross ventilation and shaded arcades FIGURE 59: SEASONAL SHADING (SUMMER)

NE

Worst-case scenario: 16:00 40° solar incl.

FIGURE 60: FLOOR PLAN OF DUPLEX APARTMENT

FIGURE 61: ILLUMINATION AND VENTILATION

FIGURE 62: SEASONAL SHADING (WINTER)

1ST FLOOR

FIGURE 63: ADAPTIVE FACADE PANELS (SUMMER/WINTER)

Adaptive facade manages the amount of sunlight entering the interior

FIGURE 66: TYPICAL FLOOR PLAN

Panels fully open to allow the maximum amount of sunlight and daylight into the raised public area

SW

2ND FLOOR

FIGURE 64: DOUBLE GLAZING WINDOW

FIGURE 65: SKYWALKS

Clear glass with spectrally selective coating

Climate features: Moving louvres on the roofs and walls for maximum shading

Solar radiation: 39° admitted Visible light: 69° transmitted

Water sprinklers in columns for cooling down passing hot wind

FIGURE 67: INDOOR CROOS-VENTILATION USING WIND COWLS

FIGURE 68: DOUBLE GLAZING WINDOW + SHADING ELEMENT

SECTION B-B

Seasonal turn over spectrally selective tint Solar radiation: 40° admitted Visible light: 63° transmitted

The shape and orientation of the hotel building provides sufficient protection of urban block from extensive solar radiation during the whole day. The indoor ventilation is maximized by wind cowls due to the lack of cross ventilation in the rooms. (Figure 67)

NE

SW

NE

Worst-case scenario: 15:00 55° solar incl.

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

Materials and landscape design

FIGURES 69: AXONOMETRIC VIEW OF “SUNSHYNE” URBAN BLOCK

Materials Las Vegas has always been a “concrete town”.

“Sunshyne” is continuing the tradition by using armed concrete as its main structure, as there are many advantages to this material. It is usually produced locally therefore cutting the transportation costs and hassle, is extremely durable and has good thermal mass properties.

Concrete is made from the most abundant mineral on earth – limestone, but it can also be made from all waste by-products from power plants, steel mills and other manufacturing facilities making it high in resource efficiency.

However, one of the key features of “Sunshyne” is the use of hempcrete as a insulating infill and facade material (Figures 70 and 71). Hempcrete is a bio-composite made of the inner woody core of the hemp plant mixed with a limebased binder. It is a lightweight, sustainable and recyclable, non-toxic, durable, fire and pest resistant material. Besides that, hempcrete consumes more carbon than it produces due to its carbon-negative properties. It also has great thermal qualities and offers good acoustic insulation, which is important in a busy city like Las Vegas.

White Photovoltaic Panels For seasonal coverage and on some facades, white photovoltaic panels (Figures 72) are used, having capability to turn the infrared solar light into electricity (90 W/m2). Front glass of the panel is matte to avoid reflection and on top of that it acts as a thermal insulator, therefore material can also be used on sun-exposed facades.

Xeriscaping Las Vegas, the driest city in US, nowadays still uses more water per person that just about any other city in the country, which is a utter paradox. Despite steady improvements and success of its “cash for grass” program that pays residents for each square foot of lawn they rip out and replace with drought-tolerant plants and rocks. Front lawns are now illegal in Las Vegas, yet still around 70 percent of city’s nearly maxed-out water diversion from Lake Mead still goes to landscaping.

Drought-tolerant plants in the desert are an extreme adaptation necessary for natural flora to survive.

Using the water-storing features of desert plants is a smart way to decorate the arid garden while conserving a rare commodity. Xerophytes have adapted to survive in an environment with little liquid water. These plants are usually smaller in order to prevent water loss from surfaces and have smaller or no leaves, sometimes they have thorns.

Some of these plants have very long roots and get moisture deep under the ground. Plants that we are using are cacti, shrubs, succulents, groundcovers and Mojave desert’s indicator species Joshua tree.

FIGURES 70: SELF-SHADED HEMPCRETE FACADE

FIGURES 71: HEMPCRETE

FIGURES 72: FACADE WITH WHITE PHOTOVOLTAIC PANELS

FIGURES 73: XERISCAPING

This taken into account, a desert-like landscape park with the technique called xeriscaping (Figure 73) is introduced for positive climatic, environmental and aesthetic reasons. (Figure 69)

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

Visualisation FIGURES 74: “URBAN CANYON”

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

References

Literature: Condicionantes Bio-climaticos en el diseño, Martin Wieser Rey, 1998

Figure 10: https://www.gaisma.com/en/location/las-vegas-nevada.html

Daylighting for Sustainable Design, Mary Guzowski, 1999

Figure 12: https://www.windfinder.com/windstatistics/north_las_vegas_airport

Natural Energy and Vernacular Architecture: Principles and Examples with Reference to Hot Arid Climates,

Page 4: Vernacular architecture

Hassan Fathy, 1986

Figure 15: https://en.wikipedia.org/wiki/Wigwam

ARCH + , Post-Oil City – The History of the City‘s Future. 2011

Figure 16: https://en.wikipedia.org/wiki/Old_Las_Vegas_Mormon_Fort_State_Historic_Park

ARCH+ 184: Architektur im Klimawandel, 2009

Figure 17: http://taospueblo.com/ gure 18: http://scalar.usc.edu/works/american-indian-film-archive/apache-dwellings

Internet sources:

Figure 19: https://www.nps.gov/nr/twhp/wwwlps/lessons/122fort/122visual4.htm

http://lasvegasplanning.weebly.com/geography--climate.html

Figure 20: https://commons.wikimedia.org/wiki/File:Taos_pueblo_habs_1973.png

http://forestry.nv.gov/wp-content/uploads/2013/06/UHI_LasVegas_Final_Report.pdf

Figure 21 and 22: Authored

https://geochange.er.usgs.gov/sw/changes/anthropogenic/population/las_vegas/

iFigure 23: https://www.tes.com/lessons/b1PvmsDPlyCPHQ/native-americans-of-the-southwest

https://www.npr.org/2015/04/17/400377057/as-lake-mead-levels-drop-the-west-braces-for-bigger-

Page 5: Passive design strategies

drought-impact

Figure 24-29: Authored

https://en.wikipedia.org/wiki/History_of_Las_Vegas

Page 6: Designing the urban block

http://lasvegasplanning.weebly.com/geography--climate.html

Figure 30-41: Authored

https://geochange.er.usgs.gov/sw/changes/anthropogenic/population/las_vegas/

Page 7: Testing the urban block

https://www.npr.org/2015/04/17/400377057/as-lake-mead-levels-drop-the-west-braces-for-bigger-

Figure 42-47: Authored

drought-impact

Figure 48 and 49: Co-authored with Nikki Alaine Panaligan

https://en.wikipedia.org/wiki/History_of_Las_Vegas

Figure 50: Authored Page 8: Climate, comfort and energy concept

http://ex25.hyperbody.nl/index.php/Msc1G10:Student5

Figure 51: Authored

https://www.archdaily.com/471249/light-matters-7-ways-daylight-can-make-design-more-sustainable

Figure 52: https://www.soliclima.es/instalaciones/lista/576-instalacion-de-placas-solares.html Figure 53: http://www.next.cc/journey/design/rain-water-harvesting

References of figures:

Page 8: Distribution of program

Page 1: “The Interview“

Figure 54: Authored

All figures: from personal archive of Christian Degenhart, Laura Mendoza and Malvina Disha

Figure 55: Authored

Page 2: Location

Page 9: Indoor comfort and high-tech solutions

Figure 1: https://earthobservatory.nasa.gov/IOTD/view.php?id=37228

Figure 56-68: Authored

Figure 2: https://knpr.org/knpr/2015-09/building-las-vegas-history-has-shaped-unique-urban-sprawl

Page 10: Material and landscape design

Figure 3: http://www.govtech.com/fs/Sprawl-Beyond-Zoning.html

Figure 69: Authored

Figure 4: https://www.npr.org/2015/04/17/400377057/as-lake-mead-levels-drop-the-west-braces-for-big-

Figure 70: http://www.archilovers.com/projects/159316/mulberry-house.html

ger-drought-impact

Figure 71: http://nationalhempassociation.org/some-interesting-faces-about-hempcrete-as-a-buil-

Page 3: Climate

ding-material/

Figure 5: http://go.grolier.com/atlas?id=mtlr033

Figure 72: http://www.issol.eu/white-solar-panel

Figure 6: https://www.nature.org/ourinitiatives/regions/northamerica/unitedstates/nevada/explore/

Figure 73: http://desertcrestllc.com/about-us/cities-served/phoenix-landscape-design/

southern-nevada-bucket-list.xml

Page 11: Visualisation

Figure 7: https://www.greenchipstocks.com/articles/army-solar-power-plant/557

Figure 74: Authored

Figure 8, 9, 11, 13, 14: https://weatherspark.com/y/2228/Average-Weather-in-Las-Vegas-Nevada-UnitedStates-Year-Round

Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

Appendix:

SOLAR RADIATION ANALYSIS

Transolar Academy report

Solar radiation on streets Las Vegas receives a high amount of solar radiation on the horizontal. It receives the highest radiation during June and september. Radiation map was created considering these three hottest months.

A reduction of unobstructed radiation by 70% on the streets will be the measure if good shading is achieved.

From the radiation map, the unobstructed radiation values of 600 kWh/sqm is reduced to 200 kWh/sqm to as low as 150 kWh/ sqm on most of the streets, which means about 70% reduction of unobstructed radiation. With the given street widths and building heights of the massing, a good shading in most of the streets is achieved.

On particular areas where radiation is about 350 kWh/sqm, just a 50% reduction of unobstructed radiation, additional shading can be put up.

SUN PATH

Daylight on interior spaces Massing was divided into floors where windowto-wall ratio of 30% and windows with 70% of visual transmittance are assumed.

External shadings can be provided to reduce the daylight hitting the areas close to the windows, specificially those facing the south.

TEST MODEL WITH 30% GLAZING

ILLUMINATION ANALYSIS

HORIZONTAL RADIATION

For commercial spaces where natural daylight is not a priotity, we can decrease the window-towall ratio further or decrease the visual transmittance of the windows that will be used.

In other areas where daylight is needed, but not enough reaches through the center part of the floor plan, rooms that do not require much natural daylight such as storage rooms, toilets, etc., can placed or larger windows can be placed on facades facing north to allow in more diffused daylight.

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Las Vegas | ABK Stuttgart | V. Aguirre, A. Escalante, M. Valinger Sluga, M. Vitkauskaite | Gebäudetechnologie und klimagerechtes Entwerfen | Prof. M. Rudolph, AM C. Degenhardt | WS 2018

OUTSIDE AIR TEMPERATURE