Autodesk Excellence in Analysis Award
Submission Template
sustainabilityworkshop.autodesk.com/excellence-analysis-award
Date: 5/10/2012
Date when the project was completed
Project Title: Joshua Tree Lodge Hotel
Name(s): Emily Greenstreet
Summary
A brief description of the project and how the design changed/improved as a result of what you learned from whole building energy analysis and/or
other studies for energy and design.
The project was the design of a hotel lodge for Joshua Tree National Park. Specific design strategies implied in
the lodge hotel include: comfortable interior temperatures; natural lighting conditions; and a separation
between public and private circulation and program. Building energy analysis greatly improved the design of
the exterior envelope of the building. Sun shading analysis helped to determine the best depth for the facades
brise soleil, which was finalized at 10’ deep after considerable analysis and adjustment. Wind rose diagrams
helped to determine the single-loaded circulation scheme and building footprint to increase cross ventilation
opportunities. Software analysis also helped in orienting the buildings’ siting and location, for example in the
decision to position the building directly adjacent to the steep mountainside on the west side.
Autodesk Software Used: Vasari, AutoCAD, Sustainability Workshop
Other Software Used: Rhino 3D, Sun Seeker
Situation, Requirements, &Design Goals
What is the context of the design (building type activities/occupancy, location, climate, intended use)? What were the design goals?
The project programmatically includes a visitors with the following special elements: auditoriums, classroom, library, indoor dining,
outdoor dining, and an outdoor amphitheatre. The project is located in Joshua Tree National Park at Cottonwood Springs. The
climatic zone is hot-arid: the Mojave Desert consists of extreme diurnal and seasonal temperatures. During the summer the daytime
highs routinely reach well over 100 degrees, and in the winter temperatures drop below freezing consistently. This extreme
temperature range combined with low humidity encouraged the building to have an increased thermal mass in order to provide
passive cooling and heating strategies. The hotel can be used for small conventions as well as a more protected residency for people
visiting the National Park. The public program has been designed so that it can be circulated and occupied by visitors who are not
necessarily staying in the hotel, without disturbing the hotel rooms.
The Design
Describe the design concept and intent based on the requirements (include initial sketches if possible). Describe the final design (include final image)
When designing the hotel there were principles established at the beginning of the project to strengthen the
overall concept and idea. First principles for the project include:
Sun Shading
To provide protection from the extreme sunlight conditions of the desert sun shading is necessary. Sun
shading is provided in the brise soleil façade on the North and South facades. The 10 foot deep brise
soleil is accessible, and also has sunshelves to further prevent sun penetration into the rooms in the
summer but which also allow some light in during the winter to warm and illuminate the rooms.
Double Bar Building Footprint
The building massing is composed of two main “bar” elements connected by public spaces. These solid
double bars act as bookends for the project. The two bars help break up the massing for the hotel
program, while providing thermal advantages for ventilation and solar access/shading.
Open Public Spaces
Between the bar buildings, the connecting open public spaces encourage social interaction. Solar
analysis helped scale the outdoor public space and the shadow-casting of the south bar into the
protected court.
Cross Ventilation Dimensions
The dimensions of the project were determined by the maximum required dimensions in order to
successfully use passive cross ventilation tactics.
Linked Public Program
Truss bridges provide connections between the double bars. The bridges also create suspended
viewing platforms at different elevations allowing for views of the desert at heights that vary from 15’
to 60’.
Site Integration
Due to the large square footage of the project it is desirable to integrate the hotel within the site to
reduce solar heat gain. Building the west façade against the side of the mountain makes the building
less prominent, as well as shading the building naturally during the afternoon and evening.
Design Process & Design Tools
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What was the design process?
What type of analysis? Whole building energy analysis, climate, sun, shadows, solar radiation, wind, etc)
What software was used?
The early stages of the design process included a detailed site analysis. Vasari and Climate Consultant were
used to analyze the climate of Joshua Tree. Monthly Diurnal Averages showed a relative stability of radiation
throughout the day and year. Sun path charts revealed where the sun is in the sky at what time of the day
throughout the year and helped dictate the slightly skewed building orientation. Sun angles provided by these
software charts can be used to determine solar shading and loading on each side of the building. Sun path
diagrams are a convenient way of showing diurnal and seasonal changes in the path of the Sun through the
sky. Their most immediate use is that the solar azimuth and altitude can be read off directly for any time of
day on any day of the year. Once an initial idea for the overall building shape was proposed it was input into
Vasari to analyze the solar heat gain on each face of the building, as well as to determine the wind flow
through the site. These diagrams helped determine the best strategies to create passive heating and cooling.
Autodesk BPAC showed that high mass walls such as the pre-fabricated concrete being used along the two
long facades would create exterior insulation to keep the building energy costs lower. Thick concrete walls
provide thermal insulation for the main spaces in the hotel.
Analysis Results and Insights [most important]
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What metrics were used? What baselines were you measuring against?
What insights did you get from analysis?
Include and describe images of the building and the analysis results. Describe sustainable features and design decisions made from
analysis results.
How did the design improve (quantitative and qualitative)? Show initial design(s) compared with final design.
Through sun shading charts and analysis I was able to design the façade brise soleil to best protect the hotel rooms. Specifically the
façade was changed by adding additional angle elements to create more protection from the western sun. Sun shelves were also
added to the South side facades to block the lower winter sun from entering the rooms. The depth of the brise soleil is 10’ because
from many sun shading studies in Vasari this proved to be the most energy efficient. The dimensions of the bars were determined by
what was shown to be the maximum dimensions to still allow cross ventilation. In the initial design the public bridges consisted of
concrete floorplates and glass exterior walls. Autodesk showed that these glass exterior walls did not provide enough protection for
the interior spaces and would act as a greenhouse creating temperatures high above the thermal comfort level. Instead, concrete
was chosen as the materiality of all the exterior faces to provide thermal mass throughout the entire building. Concrete is ideal for
desert buildings because it absorbs the harsh daytime heat and passively releases the hotter air captured during the day at night
when the temperatures are known to drop below 30 degrees.
Tips, Tricks, Tricks and Best Practices for other Projects
Working back and forth between the software and scaled models within the studied context gave the most accurate data. It also
provided a more thorough knowledge of the environment and how it would act with natural variables.
Conclusions & Best Practices for Other Projects
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Final conclusions
Specific insights from your analysis process that would be useful for others.
This was the first project where I worked extensively with Autodesk sustainability software and it proved to be very helpful. It made
the project more sustainable, and provided specific design strategies, which directly influenced the design. The most effective use of
the software was looking at the analysis that Autodesk provided and then testing it with a scaled model in the actual site of Joshua
Tree. The model was designed to look at the efficiency of the brise soleil.
More about the team & project
What’s the background of the team members? What was the context for this project?
Emily Greenstreet is preparing to enter her 5th year of Architecture at the University of Southern California.
She currently works as an intern for DP Environments, a Los Angeles based landscape architecture office. She
intends to go on to graduate school for landscape architecture.
The project was completed during a Spring 2013 studio at USC. The studio was a collaboration between USC,
PCI, and Joshua Tree National Park. PCI funded the studio to encourage new designs involving pre-fabricated
concrete. Joshua Tree National Park is looking for an architectural identity, which is what this studio tried to
create through a series of building studies that will be published for the National Park Services.