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FACADES
ACOUSTICS OF OUTDOOR SPACE Victoria Brown
Facades + Acoustics of Exterior Space
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Table of Contents Abstract Project Proposal Methodology Urban Environment Precedent Studies Literature Review Design Work
Idea Generation Site Assessment Sound Investigation Parameter 1: Material Analysis Parameter 2: Form + Process Acoustical Analysis Application
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04 06 08 11 12 34 38
Victoria Brown
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Facades + Acoustics of Outdoor Space
The urban environment is constantly evolving, increasing in scale as well as sound level. This study looks into utilizing outdoor space within the urban environment of Chicago, IL. With ambient noise affecting the activities in an open-air site, the project challenge focuses on acoustic design to enhance user experience. Modern sound manipulation methods are typically only used within indoor performance halls. Presumptions and revisions were made to apply indoor techniques in a contrastingly boundless environment. This project proposes the use of adjacent building facades: barriers that currently function exclusively to enhance the interior environment. Expanding upon these existing functions with acoustical treatment may redefine the impact the façade can have on the outdoor environment. Challenging materiality (absorptive values) and form (x,y,z planes) allow for meaningful interaction with sound produced in adjacent outdoor space. This innovation presents an opportunity for the site to facilitate powerful cultural expression and interaction.
Performance types are typically at the mercy of their arena—this study suggests that the façade may be able to adapt acoustically and structurally; allowing it the capability to accommodate a range of sound types. Form is essentially generated through sound behavior. A metamorphic dialog exists between the façade, the outdoor site, and the dynamic urban environment. This study explicitly defines a set of acoustical performance objectives and criteria for architectural acoustics in the outdoor environment. These considerations are able to be measured and predicted in the design process, and may serve as a template for future projects in synonymous context.
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project proposal Introduction: As architects, engineers, and related professionals, the concept of acoustics is very one sided. There is an understanding of acoustical values and treatments by the engineer with very little appreciation for design integration. When acoustical design transitions to the designer it can lose value and cannot easily be adjusted without a base understanding of what it is accomplishing in the project. In this study, there is an attempt to bridge that gap and provide a foundation for both ends of the profession to understand a need for strong design sense as well as acoustic functionality in architecture. Background: A variety of precedent studies were considered for this project: all relating to acoustics, detail, and design. Precedents and further research helped to guide the investigation of the initial intersection between architecture and acoustics in the urban environment. Proposed Work: The urban environment is constantly evolving, changing in form and functionality to support new economic demands. Building from existing infrastructure and medical, technological, and innovative assets within the city, increased densities, mixed-uses, and multi-modal public transportation reshape the cityscape. In this new context, thoughtful planning has established the built environment but there remains a need to connect these buildings and people together with outdoor community gathering spaces. With Facades + Acoustics of Exterior Space
less available land area, particularly for the function of parks, leads designers to seek underutilized outdoor sites immediately adjacent to free standing buildings of varied scales. This study considers how this space will serve to facilitate social interaction and cultural activities through the integration of architectural acoustics in the space. Sound must be blocked from the external environment to accommodate independent functions of the open-air site. Sound will be contained and enhanced through the form and materiality of the gathering space. Building facades will structurally support and contain panelized acoustic system. This systems forma nd materiality are defined by the needs of the ongoing activity, potentially a political speech, concert, or a collection of conversations. The structures of the adjacent building facades will determine the sound intensity and directionality, designed to reach the audience at appropriate decibels and location on the proposed site. A range of materials will be considered, from traditional building materials to composite and recycled materials, their physical properties will be assessed. Through the study of material reacions to sound and the sound produced by the intended activities of the space, a design will be identified through parametric modeling software that will present feedback of acoustical behavior and determine the quality of acoustical design. Multiple iterations will be produced, optimizing the material placement and the overall form of the building faรงade reaching out into the outdoor space.
7 The façade will be able to reconfigure its orientation and/or the surfaces exposed to the exterior to determine the acoustical treatment it will offer the outdoor space. These varied formations of the façade will impact the space in new ways both functionally and aesthetically. Different seating arrangements will be available to serve the activity going on in the space and the formation of the façade adjacent to them. Serving as an investigation in acoustics as they relate to outdoor space, architecture, and the built environment. Looking closely at surfaces, their shapes and material properties and considering how they react to sound. Determining methods and designing for ideal acoustical conditions in outdoor space is the ultimate goal. Through incorporating architectural acoustics in design, the designer is ensuring positive audible experience while simultaneously enhancing the over depth of design. A. A new urban context B. Surrounding surface conditions and consequences + opportunities (facades serve as base for acoustic functionality) C. Innovation in design and technology generating incredibly complex forms (use this to designers advantage) D. Move past speculative design where acoustics appear strong on paper and aren’t in actuality E. Set acoustic parameters into design F. Ensure strong, audible experience while simultaneously enhancing overall depth of design G. Able to input functionality of space and generate design solutions that enhance acoustically (through form and materiality)
Timeline: Aug 2013: Thesis Prompt Oct 2013: Exploratory Research Dec 2013: Research and Literature Review Compiled Jan 2014: Initial Design Process Feb 2014: Research Materiality Mar 2014: Acoustical Analysis Software Search April 2014: Design Production April 28, 2014: Final Presentation
Significance: As urban environments become more prevelant you want to have this access to designing for outdoor sites within the environment. As this becomes a permanent resience for millions of people, consider their quality of life, indoors/outdoors as well as social and cultural connections to place, person, and their lives. Victoria Brown
methodology Idea Generation
Site Assessment
Sound Investigation
Parameter 1: Material Analysis
Parameter 2: Form + Process
Acoustical Analysis
Application
Categories of process in design work Participants: For this thesis project, the sole researcher and designer, Victoria Brown, couducted all methods, research, and completed drawings. Academic advisors Walter Grondzik and George Elvin provided direction in regards to acoustics and design understanding. Acoustic consulting firm, Kirkegaard Associates provided insight and critique during the design process. Coding specialist, Arthur van der Harten provided assistance in providing acoustical software and user guidance.
Facades + Acoustics of Exterior Space
2. Materials: Once this information is known, the design process may begin and a grid may be generated, laying out materials for eventual façade application. The consideration of its impact on the interior of the building must also be considered. Several iterations will be produced to determine optimization of assembly. Such software programs will be utilized to determine sound paths and manipulations: • Pachyderm Plug-in for Rhino 5.0 As materials are placed in a grid or panelized array, the assembly may begin to evolve in the third dimension. Panelization was generated through: Grasshopper Plug-In for Rhino 5.0 Additional convex and concave movements will
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Procedure: For the feasibility and accuracy of the project a system of methods will apply to the investigation of acoustics in an outdoor environment. Initial decisions consider the functionality of the open-air site set in close proximity with buildings of varied uses in an urban environment. Specific functions may include the use of the space for a collection of individual conversations, a political speech, or a soft rock performance. The characteristics of the sound generated from these functions must be documented. Their • •
continue to affect the interaction of sound to surface. Sound directions and intensities will be altered and will need to be continually adjusted to provide users with appropriate acoustic conditions. The consideration of an adaptable system may allow the array of materials and their form to reconfigure to optimize sound quality to meet current needs. Perform final analysis of architectural acoustics using listed software applications. Consider seating arrangements to complement the wall forms for each of its three proposed configurations.
Design: The project looks into the base conditions of the site as well as two progressive iterations of facade development for the site.
sound levels (dB) sound frequencies (Hz)
These qualities will help in determining their interaction with the materials cladding the adjacent building structures. Additionally a list of materials (concrete, wood, metal, glass, plastic, and composite materials) used in the design space must include acoustical characteristics: •
absorption coefficient
physical characteristics: • • •
standard product dimensions structural capacity weatherability (density and porosity)
and environmental impact: •
embodied energy level
This data will help in understanding performance output and potential material input. A matrix of the materials absorption coefficients at particular frequencies will describe the direct relationship. Victoria Brown
site selection
Interpreting a particular sound as unwanted involves subjective judgement by an individual. Typical characteristics of unwanted sound include pure tones and sharp impulses. Car noise impacts the largest number of city dwellers. Because this type of noise and activity is so comA survey with 1,000 citizens found that 53% of mon people are most tolerant of this Vancouver citizens felt that their city has become over air traffic or trains. According to noisier in recent years, while only 6% felt that it had the Chicago Municipal Code all amplified sound must be approved by the become less noisy. Trend: Average sound intensity Chicago Park District. All sound must has doubled roughly every six years corresponding to be directed away from residence zoned a 3dBA increase in the average sound level. - City of parcels and all speakers must be on a site plan. Beyond this Vancouver Noise Control Manual identified statement there is nothing mentioned regarding the acoustics of any site or regulations pertaining to inappropriate sound levels in the city. Facades + Acoustics of Exterior Space
& the urban environment Different neighborhoods embody music styles that have evolved with time.Cultural identity also steems from esteemed artists that have developing their sense of music talents in a particular area the city. Hip hop artist Kanye West comes from the the south shore of Chicago. istricts in terms of music pockets, interweaving to create the thread of the city.
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Precedents Precedent Studies Victoria Brown
The Pritzker Pavilion
Architect:Gehry Partners, LLP Structural Engineer:Skidmore Owings & Merrill Mechanical & Electrical Engineer:McDonough Associates Theatre Consultant/Lighting Designers:Schuler & Shook Acoustical Consultant/Audio Systems Design:The Talaske Group Client: Millennium Park
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Pritzker Pavilion feat. Wentz Concert Hall— “How do you make everyone - not just the people in the seats, but the people sitting 400 feet away on the lawn - feel good about coming to this place to listen to music? The answer is, you bring them into it. You make the proscenium larger; you build a trellis with a distributed sound system. You make people feel part of the experience.”- Frank Gehry (arcspace) Gehry’s stainless steel sculptural forms are an interesting feature and the signature style of most of his work, and may have some acoustical intention on the Pritzker Paviliion outdoor venue. There are clusters of speakers set into these forms at the front of the performance stage. The stage is at maximum capacity with 120 musicians along with a balcony space that will support 150 choir members. This centrally located venue is able to seat 4,000 persons in the bombshell pavilion area and extends out accommodating 7,000 lawn seats. The acoustics are supported in such a large venue through the addition of elevated trellises that form an open-air acoustical canopy above the lawn space, spanning 600’x300’ forming the shape of a flattened dome (arcspace). Structurally, cylindrical concrete pylons support them with stainless steel cladding to integrate them into the design. The sound generated through this sound system allows for split noise as well as a fuller sound
Interesting features of the pavilion include the ability to close the stage with glass doors to utilize the indoor space for banquets and other functions during the cold winters of Chicago. In the summer, however, there is a lighting system the enhances the curving stainless steel forms and lights the terrace with small illuminations resembling the twinkling stars above. Large glass doors allow the Pavilion to be used for public functions, banquets, receptions, and lectures, during the winter months. The acoustical engineer, Talaske of The Talaske Group, pioneered the idea of using suspended overhead speakers with digital sound processing to reproduce indoor quality sound to the audience as they sit under the stars. Although the Pritzker Pavilion may be the reason for Talaske’s renowned success, he reflects fondly on a more recent project, the Wentz Concert Hall in downtown Naperville, IL. The project focused on the material qualities and forms themselves. Talaske utilized maple panels that have defined grooves and projections to diffuse high-pitched notes during a performance. He coins the term for these panel treatments as “perturbations”, altering the regularity of their surfaces and generating an acoustical presence through their distribution of sound in unique ways. The most unique feature of the Concert Hall are mesh walls that serve as sound openings to empty rooms which sit on either side of the performance stage at balcony level. These rooms clad in hard surfaces are supported on a separate structural grid from the rest of the hall. They are not subject to vibration or external sound sources. They serve to control excessive loudness and express the reverberation of the performance. (Chicago Tribune)
Victoria Brown
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Hollywood Bowl Hollywood Bowl – revision of the 1929 outdoor pavilion in southern California. The previous performance shell was too small to contain the entire LA Philharmonic Orchestra and so the first stage of construction was rebuilding the shell a third larger while maintaining the modern aesthetic designed by Frank Lloyd Wright. The new dimensions of the overall shell performance stage are 111’x53’. The shell structure is divided into four different sections, supported by ten tubular steel truss spines, the largest one set at 60 feet tall and 130 feet wide(25,000lbs). An additional 350 tons of structure steel reinforcement were placed, primarily to support the sound and lighting equipment as the shelf was a load bearing member itself. Four new video screens were put in place to add to the audiovisual experience for the venue. A turntable was built into the stage floor to allow for efficient set changes. All equipment and additional components were fabricated off-site during the outdoor performance season and installed in the fall of 2003 and spring of 2004. Total renovation and new construction costs total 25M. After the new shell was in place the acoustics improvements were underway. During the initial design phase the engineers were designing for the 485 throw distance out to the back of the outdoor seating area and the team wanted to avoid using delay towers out in the audie
nce seating space. The first addition was a halo overhead structure called the “Corona”. A 60’x90’ ellipse, the Corona is an aluminum acoustical band that hangs directly over the Hollywood Bowl stage. Its height is set at a 10 degree angle and varies from 28 feet at the front of the stage to 32 feet at the rear of the stage. There are optional motorized side sections most utilized for rock and roll performances. Structurally, the band was mounted on a pulley system and is able to be raised and lowered with pistons and four winches, typically used in nautical engineering. The center of the band contains a grid of lighting and sound equipment. This space is subdivided into four motorized baffles that respond to different sections of the orchestra: strings, woodwinds, brass, and percussion. The four baffles are further divided into individual reflector panels that can shift upward to adjust the sound quality of a particular performance. When the system is not needed, it can be entirely removed and stored. In addition to the acoustical halo, there were V-DOSC loudspeakers placed on the front of the shell in a linear array set at 120 to 72 feet above stage level. With these two elements forming a hybrid system, the throw distance for the performance venue was not a problem and allowed for the localization of sound for the performers. The number of loudspeakers integrated into the halo suspension was the intent. Victoria Brown
to eliminate house delays. With structural limitations, an upper and lower section were created, totaling 18 three-way loudspeaker V-DOSCs with 6 two-way DV-DOSC linear arrays out facing the audience on either side of the stage. There was space between the two sections to place subwoofers to generate low-frequency control that would not be captured with any other arrangement. Both the upper and lowers sections are able to cover frequency ranges from 200 Hz and above. The frequencies below 200 Hz are controlled by the 24 linear arrays placed symmetrically on the front sides of the shell, allowing for greater throw distance of the bass sounds while directing all sound more specifically to the seating arena (eliminating split noise in an otherwise residential neighborhood).
With assistance from the Corona, the shell provides a reverberant effect to the sound being produced on stage. In addition to the baffles overhead, the musicians are able to hear themselves and synchronize their delivery, resulting in better quality music from the source. Research for the optimal shell design has been ongoing since 1922 for this project. It took three years for the new team to generate a new solution, and in turn resulted in demolishing the existing structure. Overall the acoustics of the Hollywood Bowl Facades + Acoustics of Exterior Space
19 have improved so much that the engineers are able to rely much less heavily on mechanical amplification to project the sound. As advanced as these systems are, they still present distortion of sound. The Hollywood Bowl serves as the foundation of sound for Los Angles. With such extravagant sound and lighting capabilities the audience receives an experience of the highest quality. “The New Hollywood bowl is a place where everyone can escape and enjoy the sound of life.�-Godges,
Architect: Hodgetts & Fung Design Associates Steel Contractor: Milco Executive Architect: Gruen Associates Theater Design: Fisher Dachs Associates Acoustic Design: Jaffe Holden Acoustics Steel Coating: Sherwin Williams Structural Engineer: Miyamoto International, inc. Mechanical and Electrical Engineer: Gotoma Engineers Rigging Designer: Tri West Engineering General Contractor: Matt Construction Steel Fabricator: S&S Steel Fabrication
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The Wild Beast The Wild Beast—An indoor/outdoor pavilion that defines the variances between acoustical design for each environment. This building on California’s Institute of the Arts serves as both a recital hall and an outdoor performance shell. The shell is a thin plane folded over the performance space. The use of parametric modeling was utilized to generate its unique form that will resonate the sound. The inward facing surface of the shell is comprised of panelized surfaces that are able to shift in orientation to adapt to different performance needs. They are able to rotate, slide, and pivot, which is particularly important as the sounds of the musicians need to direct inward or outside to the lawn seating space. Servos are able to fine tune the resonance of the volume. The exterior cladding is the copper-hued shingles. The overall form is supposed to resemble an instrument. The structure is titled, The Wild Beast, and is set at the very front of the campus. It was an awkward site with severe contours that lead the team to consider an organic form in its rectilinear context. The unique acoustical shell is cantilevered from its base and there are glass sliding doors on the south side which allow for the interaction with the outdoor seating space. Surfaces on the interior north face assist in projecting the sound out to the audience. There are also clerestory windows that are operable to complement the instrumentality, an acoustic tool typically present in the back of a stage.
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Federation Square—Perhaps the initial inspiration for the project, this multistructure project includes a faceted geometric panel system as well as sound mitigation of the external city environment including a railway that rests directly below the site. Federation Square spreads out an entire city block in the center of Melbourne, totalling 36,000 square meters. The site is right across the street from the historical Flinders Street Train Station and consequently train lines run below the entirety of the site. Special vibration mitigation was included in the foundation for the site.
Federation Square The pavement consists of cobblestones made of Kimberley sandstone. There are stone pavers that serve as the edge for terraces, stairs, planters and seating areas. Victoria Brown
Situated in the heart of Melbourne, the site of cultural buildings and a plaza for impromptu interacts builds upon the existing history and experience within the city. The project was a part of an international competition wherein the winners, Lab Architecture, had never actually built any of their previous designs. The raw creativity and forward thinking design style sets this assembly of buildings and open site apart from the rest of city, while celebrating the city within it. Within one of 9 cultural buildings the National Gallery of Victoria’s collection of Australian Art is displayed. A visitor center is also located on the site. The open plaza space in the center of the site is capable of accomodating up to 25,000 people for various functions from soccer games to rock concerts.
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Acoustically, this project discusses the vibration control against the underground train system located just below the site. Beyond that, there was little to no information regarding the acoustical value of the facade panels themselves. This missed opportunity was encouragement to explore this particular realm of functionality. With such diverse activity positioned in the center of the square, there is great opportunity to enhance sound quality for events, particularly musical in need of speaker enhancement. There are three cladding materials used for the panelized facade: zinc(perforated and solid), sandstone and glass. Each of the panels is shaped as a single triangle, with similar proportions maintained across a five tile panel set. Framing this geometry makes it easy for reconfiguration and surface development. The central plaza space is the focus of the site establishing the relationships with the surrounding buildings as well as the city and landscape around the site. Victoria Brown
resonant chamber
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Resonant Chamber, an interior envelope system that deploys the principles of rigid origami, transforms the acoustic environment through dynamic spatial, material and electro-acoustic technologies. (http://www.archdaily.com/227233) The project was developed through an iterative process. Each panel performs absorption, reflection, or electro-acoustical function. There are circuit controls that controls the movement and employment of electro-acoustic amplication in response to surrounding sound conditions. Different levels of exposure for each of the different panels is possible as the geometries reconfigure themselves. The project is on the forefront of responsive envelope design as well as kinetic tessellated architectural systems. Victoria Brown
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UTS Great Hall &Balcony Room A project by DRAW Architects out of Sydney, Australia. “The Mantle� a fluid skin of perforated aluminum comprised of more than 1000 unique facets. The Mantle lines the ceiling and walls integrating lighting, audio-visual, fire and mechanical services into a dynamic whole, that breathes new life into the space.
Although this project may be focused on indoor application, the project provides information regarding perforation of the panels and the impact that deflection can have on sound behavior. Additionally, the structure to support triangular geometries was considered when working with a network of triangular forms connecting to the structure of the building.
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Victoria Brown
Sub Themes: Transitioning City Structure: outdoor space relevance/ connectivity/intersection (soundscape) --After the Crisis: The Metropolitan Revolution The thesis design project is set into the evolving city structure. Set in a period in the US economy where cities and metropolitan areas are becoming more dependent and capitalizing on their distinctive assets to serve as a catalyst for economic stability. With new market forces such as fiscal constraints, energy source transitions, demographic shifts, technological advances and climate change, will drive cities are evolving their economies to meet these newchallenges. In response, the form and function of cities will adapt to operate more efficiently to output more sustainable, innovative goods and services. Cities across the country are already leveraging their assets. Denver and LA are are investing in transformative infrastructure; transit systems on both local and global scale. Portland and Minneapolis are connecting small businesses to global markets and forming networks geared toward innovation. New political structures are unfolding on a more local scale and considering the input of business leaders to create more effective and relevant policy. The site specific to this thesis is located in the city of Chicago, a hub of finance and at the geographic center of national transportation. Using their diverse industry base to their advantage the city can work to develop connections between small businesses to global markets and form networks geared toward innovation built upon preexisting assets and their supportive infrastructure. This evolving cityscape provides an unique opportunity to focus in on the dispersed, open-air environments that may be utilized for public gathering spaces that are able to contribute to quality of life and cultural enhancement. --Cities as a Lab: Designing the Innovation Economy “Building the relationship infrastructure” Not all of these collaborate environments must be set indoors in a formal environment. Set at the intersection of buildings and transit. Working to incorporate the adjacent physical structures to form defined outdoor space with idea acoustical conditions for a variety of social and cultural activities. All components of city networks are being designed, allow for these gaps, open-air environments to be utilized and perform at their highest level of capacity (acoustically and spatially speaking). Innovation districts with innovative outdoor spaces. They are able to maintaining a sense of human scale and the natural environment that are es
Literature Review
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Facades + Acoustics of Exterior Space
sential for human survival, more productive and healthy city centers. Focusing on the acoustic qualities to allow for greater functionality of the space to be used as a platform for discussion, entertainment and socialization. Business leaders take more control over policy decisions, allowing for opportunity for a more local governing body with more transparent ideas and accessibility. Bringing businesses together in collaboration requires close proximity and shared facilities with thoughtful planning. Existing and new buildings can be designed for adaptability, as the market needs change, so do their functions. -------As these new plans come together, consider outdoor needs… Planning and zoning must accommodate higher densities, mixed and adaptable uses, and more efficient transit systems. They must not eliminate these remaining outdoor spaces. These new land use policies will force designers to rethink signature public spaces like parks and community gathering spaces. These gathering spaces bind the built environment and its users together, and cannot be neglected. The thesis design is a proposed solution to this issue. Opportunity to engage intersections of citizens and buildings and to provide them with quality experience. Utilize space through experimentation, use of existing buildings that may enhance developing space. On the level of acoustics, an important quality in design, especially in an open-air space surrounded by a hectic urban environment—how do you provide users with functional space, especially pertaining to socialization, political discussion, and cultural performance? --The New Soundscape As this project looks at the outdoor environment and the involuntarily engagement of the external sounds of the city. Sound of nature, humans, electrical, mechanical gadgetry, tools and technology are permeating is an outdoor space set for other specific functions dependent on specific acoustic conditions. This is a particular advantage of indoor environments with partitions that intentionally block environmental noise from penetrating their unrelated sound use. “The modern hardedged city masks the voices of its human inventors.” These sounds can be overwhelming and the idea of creating an open-air environment with minimal interruption is part of the design challenge. What forms and
35 applications can provide enough barrier to experience separate functions without interruption? “Even in the hearts of cities there are reservoirs ofsilence.” Using the existing city grid of development to compose moments or sites of their own acoustical agenda. The author, Schafer, suggests that the there is a definable difference between noise and sound. Rapid, irregular sounds are considered noise consistent with the constant lull of the city. Regular motions, oscillations, vibrations, swings and periods are sounds related to the musical performances taking place within the outdoor gathering space. Have the ability to utilize this niche within the cityscape to transform noise of the city to sound of conversation and instrumental performance. But how will this spectrum of sounds of these activities behave in terms of decay and reverberation in an open-air environment. 2. Sound Input and Output: Performance (Output) and Surface (Input) --Acoustic Absorbers and Diffusers This book provides technical information on how to control sound qualities, primarily in concert halls and enclosed environments. The challenge will be relating these methodologies to the exterior environment where less research has been conducted and less resources are available. Making deductions and generating hybrid forms in the outdoor environment with use of adjacent building faces will be necessary to treat the sound in the outdoor site. Relevant topics include reverberation control, modal control (intelligibility of speech) and configurations for stage enclosures for performances. And suggests natural noise control concepts and diffuse sound fields ideal for outdoor environments with sound coming from many directions, especially in urban context lined with high-rise buildings. Sound within the proposed site will be analyzed in terms of sound level (dB) and frequency (Hz). In order to analyze the acoustic properties of materials within the space it is important to make note of the noise reduction coefficient (NRC), which is the amount of sound energy that will be absorbed when hitting a particular surface. Additionally, the absorption coefficient which is similar but describes a material’s propensity to scatter or diffuse sound. Sustainable alternative materials are offered as replacements and there is an emerging market for recycled materials in acoustics including recycled cloth, metal, foams, wood, plastic, and rubber. Rubber is par-
icularly effective in absorbing sound with its elastic properties and is able to be used in exterior applications inserting binders and applying paints and coatings without compromising the absorptive properties. Considering the harsh conditions of an outdoor space, fibrous materials, such as plastics, work well as covers and will reduce high frequencies while the thick porous materials they are covering may serve to reduce the low frequencies (Cox, D’Antonio, pg. 159). They may be able to work together when responding to the acoustics present in a space. There is adaptability potential when the cover can be added or removed depending on the frequencies of a particular performance. Additionally, absorptive qualities of trees and vegetation are relevant in an outdoor environment as they may be able to provide value acoustically. The book, Acoustic Absorbers and Diffusers, provides examples of how surfaces scatter sound corresponding to their absorption coefficients and geometries. This relationship of material properties and form will be identify the parameters of design and drive the optimization of the acoustic assembly. Understanding how sound behaves with different geometries including plane surfaces, concave, convex, and optimized curved surfaces as well as volumetric diffusers and hybrid surfaces are important in generating a form customized to the site location and its environment. Understanding these sound behaviors will generate an initial digital geometric model with the opportunity for several iterations and improved performance. 3. Acoustics Specific to the Outdoor Environment: Sound Behavior and Environmental Noise --An Approach to the Acoustic Design of Outdoor Space The thesis design is considering an open-air, urban site where the existing built environment is imposing spatial constraints permeated by environmental noise. These design challenges require understanding of sound behavior as well as manipulation techniques that will be valuable in an uncontained space. The reading, ‘Acoustics Specific to the Outdoor Environment’, are subject to design in the same way that aesthetic considerations would be. With ideal acoustic conditions predetermined for the space and its proposed activities, different acoustic values such as noise levels are required to provide the users of the space with intelligible sounds and valuable interactions. Masking the external set of sound information while enhancing the sound Victoria Brown
information while enhancing the sound information being generated in the space is the primary acoustical design challenge. Utilizing existing boundaries for the site as well as implementing additional sound barriers and absorbers, the management of sound in the space is possible. 4. Façade Structure and Functionality: Forming a Symbiotic Relationship --The Role of Building Facades – Curtain Walls Emphasizing the importance for building facades to their interior environment is an argument of the past. But to build upon its current functionality, there needs to be a deeper understanding of how the façade works and interconnects multiple uses. Initially the façade serves as a first impression or an aesthetic definition of the building it is enclosing. It plays a critical role in the functionality and dynamics of the interior space as well as plays a large role in determining the energy performance of the building. Current façade innovation surrounds energy savings for the interior environment as well as efficiency in thermal properties, daylighting, and weatherability of the design. The façade must react appropriately to the location and orientation of the building. Constantly learning how the building may improve better with changes made to the façade. The idea of the façade serving not only the interior environment but the adjacent exterior environment presents may stipulations. The addition of an acoustic assembly or designing the fundamental structure to support appropriate sound manipulation is being studied. These additions may not detract from the functions of the interior or the overall energy performance of the building. Design parameters, building type, material components, assemblage, maintenance are all considered when working to make the building façade dynamically react to both interior and exterior performance. 5. Sound and Architectural Experience Intersect: Psychoacoustics --Sound, Awareness, and Place: Architecture from an Aural Perspective In urban environments, transit lines and free-standing buildings may diminish or increase unwanted noise and affect sound levels, as well as diffuse, reflect, and absorb sound within the site. Orienting an outdoor site so that it utilizes these features is key along with the placement of trees and vegetation, serving as an acoustical barrier between the noise of the city and the site. Particularly adverse to facilitating acoustics in the open-air urban environment are modern materials which clad the skyscrapers, metros, and surrounding infrastructure. Glass concrete Facades + Acoustics of Exterior Space
and steel create an environment of infinitely reflecting surfaces. This is where the design opportunity presents itself. Looking way back to the Renaissance period before these new material uses, Leon Battista Alberti saw a fundamental unity between music and geometry. “Music is geometry fashioned into sound. In music the very same harmonies are audile which informs the geometries of a building.” (Bryant, pg. 5)
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references Arcspace.com. Jay Pritzker Pavilion Gehry Partners,LLP (1999-2003).http://www.arcspace.com/features/ gehry-partners- llp/jay-pritzker-pavilion/
Augoyard, Jean-Francois., Torgue, Henri., Sonic Experience: A Guide to Everyday Sounds. McGillQueen’s University Press. 2005.
Bonner, Tom., The Wild Beast/ Hodgetts + Fung Design and Architecture. Arc Daily Selected Works. http://www.archdaily.com/154187/the-wild-beasthodgetts-fung-design-and- architecture/
Brown, A., Muhar, Andreas., An approach to the acoustic design of outdoor space. Journal of Environmental Planning and Management. Taylor Francis Online. (Volume 47, Issue 6) 2004. (pgs. 827-842)
Godges, Maximillian., Hollywood Bowl Ressurected. http://hollywoodbowlressurected.wikispaces.com/ Hollywood+Bowl+Resurrected. Fall 2009.
Bryant, John., Sound, Awareness, and Place: Architecture from an Aural Perspective. Proquest Learning Company. 2008.
Johnson, Steve., Rick Talaske has an ear for perfection. Chicago Tribune. September 20, 2011.
Cox, Trevor., D’Antonio, Peter., Acoustic Absorbers and Diffusers: Theory, Design and Application. Second Edition.
Lambert, Mel., Facility Profile: Upgraded Sound for Legendary Hollywood Bowl. http://www.mediaandmarketing.com/13Writer/Profiles/PAR.Hollywood_ Bowl_2004.ht ml September 2004.
Katz, Bruce., After the Crisis: The Metropolitan Revolution. The Brookings Institution 2013. Speech given May 21, 2013.
The Wild Beast - Cal Arts. Archinect Firms. http:// archinect.com/firms/project/3404/the-wild-beastcalarts/86620272
McFarquhar, Dudley., The Role of the Building Façade – Curtain Walls. McFarquhar Group Inc.
Pertaining to the Literature Review: A collection of works by local leaders., Edited by the American Institute of Architects., The American Institute of ArchitectsCities as a Lab: Designing the Innovation Economy.
Noise Control and Room Acoustics in Building Design. Architectural Record Continuing Education Center. McGraw Hill FInancial. 2013. Schafer, Murray., The New Soundscape. 1977.
Victoria Brown
Idea Generation Intersection between the urban environment and architectural acoustics.
Facades + Acoustics of Exterior Space
39
Urban Context Open Air Spaces Adjacent Buildings Materiality Adaptability
Social Opportunities Form
Facade [Curtain Wall]
Funtional Opportunities
Daylighting Thermal Barrier
Weatherability
Political Speech
Soft Rock Concert
Views
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MITIGATE BACKGROUND NOISE AS TO NOT OVERWHELM USER AND FUNCTION OF OUTDOOR SITE -- WHILE MAINTAINING SENSE OF URBAN SPHERE ENHANCE THE QUALITY AND LEVEL OF DIRECT SOUND BEING PRODUCED
CONSIDER SYMBIOTIC RELATIONSHIP BETWEEN THESE TWO SOUND SCAPES WITHIN THE CITY CONTEXT KEY TERMS IN ARCHITECTURAL ACOUSTICS: THROW DISTANCE (+) DIRECTIONALITY SOUND PRESSURE LEVEL FREQUENCY ARTICULATION BACKGROUND NOISE FLUTTER ECHO REVERBERATION TIME CONDITIONS OF A WAVE
105 FT
DISTANCE AND DIRECTION THAT DIRECT SOUND TRAVELS ON THE GROUND PLANE INTENSITY OF SOUND MEASURED IN DB (DECIBELS)
60 FT
DISTANCE BETWEEN WAVES
POTENTIAL TO MAKE OUT DETAILS OF SOUND 40 FT
ACCUMULATION OF SOUNDS IN LARGER ENVIRONMENT BOUNCING BETWEEN TWO SURFACES OCCURS WHEN NOISE BOUNCES BETWEEN TWO SURFACES ON SITE
20 FT
TIME THAT IT TAKES THE DIRECT SOUND DB TO DROP BY 60 B
REFLECTION
DIRECT SOUND A
SURFACE_SOUND INTERACTION
Facades + Acoustics of Exterior Space
C
REVERBERATION
0 FT
41
Site Assessment Victoria Brown
Facades + Acoustics of Exterior Space
43 Chicago—a city of density with diverse cultures and energy. Different districts of functionality, dynamism and design— choosing to look at the districts in terms of sound pockets, interweaving to create a dialoge of the city. With the collection of environmental noise: jet engines sailing across the sky, cars honking in traffic, a jackhammer being used in construction, or a child crying over a lost balloon; makes Occupants of a building make the transition from indoor, conditioned space to the outdoors. Considering how to minimize these noises while mainting a calm sense of understanding that the world is there: you’ve chosen to live a city afterall. The benefits of urban energy are there and the idea of gathering for performance is celebrated: why not in outdoor space? Considering how to arrange this space not only in a spatial sense, acoustics must be considered to accomodate the functions of conversation, presenation, or musical performance. Keeping outdoor functional possibili ties open with acoustic tools maybe the facade of theadjacent building becomes the framework for this treatment.
Social scientist, Katz, and design leaders see the future of cities reshaping to focus innovation with global reach. Connecting small entrepreneurial firms with large corporations and redesigning the buildings to adapt to company growth and transition. Increased public transportation available to the public, sets the pace of the city even higher. Remaining outdoor spaces are great opportunities to create impromptu meeting places and organized events. Considering the environmental noise of the city and the hard surfaces of the existing skyscrapers, acoustics are pivotal in providing functional, meaningful outdoor space within the bustling urban environment.
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POPULATION
2.7M
Facades + Acoustics of Exterior Space
BUSINESSES
4K
PUBLIC TRANSIT LINES
224MI
SOU
8
45
UND LEVEL
84dB
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ZONING PUBLIC LAKEFRONT PRIVATE LAKEFRONT RESIDENTIAL MIXED USE CORE DOWNTOWN Facades + Acoustics of Exterior Space
CAR 10,000-14,999 15,000-19,999 20,000-39,999
47
PEDESTRIAN 10,000-24,999 5,000-9,999 0-4,999
TRAIN Brown Purple Pink & Orange Lines Blue Line Red Line
Victoria Brown
sounds of the city People
Birds
Air Traffic
Construction Public Transportation
Facades + Acoustics of Exterior Space
BACKGROUND NOISE ELEMENTS
49
60 70 80
dB
90
100 110
Industry
120
125 250
Vehicular Traffic
500 Hz
2k
4k
Lakefront
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Sound Investigation
POTENTIAL ACTIVITY SOUND CHARACTERISTICS
0 36 63 Hz Hz Hz
4000 Hz
120 dB 0 36 63 Hz Hz Hz
4000 Hz
80 dB
0 36 63 Hz Hz Hz
4000 Hz
60 dB
Comparing the range of activity types to focus on within the site: A soft rock concert involves the greatest range of frequencies and highest sound levels and will be further evaluated when designing around enhancing a facade system. On the right, the instruments that comprise a soft rock concert are broken up by average frequencies and in the bottom right image the soft rock sound source is expressed in sound intensity levels per frequency. Facades + Acoustics of Exterior Space
51
SOFT ROCK CONCERT INSTRUMENT FREQUENCIES
125
63
250
500
1000
2000
4000
8000
Hz
SOUND TYPE: SOFT ROCK CONCERT
63
125
250
500
1000
2000
4000
8000
Hz Victoria Brown
Parameter i: Material Analysis
Facades + Acoustics of Exterior Space
53
Victoria Brown
analyze results: foam and fibrous materials have highest absorption coefficients.. composite materials (man-made) are highest with ability to withstand elements in an outdoor application
1.2
1
.8
.6
.4
.2
0
Facades + Acoustics of Exterior Space
50
63
80
100
125
150
160
200
250
315
400
500
Hz
630
800
55 CONCRETE FINISHED CONCRETE UNFINISHED BRICK GLASS (4MM) GLASS (6MM) GLASS (LARGE PANE OR HEAVY PLATE) GLASS (DOUBLE GLAZING) WATER METAL (CHAIRS) PLASTIC (HDPE) PLASTIC (NATURAL FIBRE REINFORCED) PLASTIC (RUBBER) PLASTIC (KALWALL) GLASS WOOL FIBRE CEMENT FIBRE CEMENT PERFORATED 28.3% METAL (PERFORATED 9.1%) METAL (LINI NANOMATERIAL) WOOD (PLYWOOD PERFORATED 18.1% WOOD (CEDAR + MINERAL WOOL) WOOD (MDF PERFORATED 4.5%) WOOD (MDF PERFORATED 18.1%) FOAM (FLEXIBLE POLYURETHANE) 1K
1.25
1.6K
2K
3K
4K
5K
8K
FOAM (RIGID POLYURETHANE) FOAM (EXPANDED POLYSTYRENE)
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FOAM (EXPANDED POLYSTYRENE) FOAM (RIGID POLYURETHANE) FOAM (FLEXIBLE POLYURETHANE) WOOD (MDF PERFORATED 18.1%) WOOD (MDF PERFORATED 4.5%) WOOD (CEDAR + MINERAL WOOL) WOOD (PLYWOOD PERFORATED 18.1%) METAL (LINI NANOMATERIAL) METAL (PERFORATED 9.1%) FIBRE CEMENT PERFORATED 28.3% FIBRE CEMENT GLASS WOOL PLASTIC (KALWALL) PLASTIC (RUBBER) PLASTIC (NATURAL FIBRE REINFORCED) PLASTIC (HDPE) METAL (CHAIRS) WATER GLASS (DOUBLE GLAZING) GLASS (LARGE PANE OR HEAVY PLATE) GLASS (6MM) GLASS (4MM) 50
63
80
100 125 150 160 200 250 315 400 500 630 800 1K 1.25 1.6K
Hz
Facades + Acoustics of Exterior Space
2K
3K
4K
5K
8K
BRICK CONCRETE UNFINISHED
57
Fibre Cement 1.0
ABSORPTION COEFFICIENT
.9 .8 .7 .6 .5 .4
.3 .2 .1 0 50
63
80
100
125
150
160
200
250
315
400 500
630
800
1K
1.25 1.6K
2K
3K
4K
5K
Hz This material has high absorption values at mid to high range frequencies. This frequency range includes train and car noise and is located on the perimeter of the site as a barrier preventing the sound from entering the site. Victoria Brown
8K
kalwall
ABSORPTION COEFFICIENT
.6
.5
.4
.3
.2
.1
0
50
63
80
100 125 150 160
200 250 315 400 500
630 800
Hz
1K
1.6K 2K
3K
4K
5K
8K
High Absorption at Low to Medium Frequencies. This material is being placed at the top of facade, working to mitigate the overall sound particularly air traffic. Facades + Acoustics of Exterior Space
59
hdpe
ABSORPTION COEFFICIENT
.7 .6
.5
.4
.3
.2
.1 0
50
63
80
100 125 150 160 200 250 315 400 500 630 800 1K 1.25 1.6K
2K
3K
4K
5K
8K
Hz High Absorption at high frequencies, this material has the most contact with the direct sound source on site. HDPE is placed to reflect sound back into the audience, making the performance feel more alive. Victoria Brown
SELECTION TRANSPARENCY
DENSITY
SURFACE_SOUND INTERACTION
Fibre Cement 18.1% PERFORATED ABSORPTION
kalwall REFLECTION
=
hdpe
HIGH DENSITY POLYTHYLENE
DIFFUSION
Facades + Acoustics of Exterior Space
=
61
1 2 3 B
4
C A
Victoria Brown
ITERATION i SUB STRUCTURE
PANELIZATION
FACADE MASSING
BASE CONDITIONS
SITE
Facades + Acoustics of Exterior Space
ITERATION ii
63
Victoria Brown
Parameter ii: Form + Process 1
1 15555 15 155
170
19 FT
29 FT 29
2
966
2
110
51 FT
2
3
122 FT F 31 FT
3
100
130 95
4 26 FT 10 FT
Facades + Acoustics of Exterior Space
175 165
4
65 state range or average overhang distance necessary to contain sound in space so that it does not all completely dissipate while allowing for the site to remain open to the urban experience.
1 23 FT 23 955
11 FT
17 FT 17 122255 1125
2
21 FT
145 112 240
3
20 FFT
100
70
58 FT
4
222 FT 170
Victoria Brown
panelization process
Facades + Acoustics of Exterior Space
67
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Facades + Acoustics of Exterior Space
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Victoria Brown
Acoustical Analysis
ITERATION I
DIRECTIONAL REFLECTION
The first iteration is sending the sound beyond the audience and off of the site
Facades + Acoustics of Exterior Space
ITERATION II
71
switch this image!!!!
In this next iteration, the facades were scaled down and the concave form reflects the sound from the performer directly into the audience area at the appropriate distance. Victoria Brown
ITERATION II
D
WITH STREET NOISE C
BASE CONDITION
ITERATION I
BASE CONDITION
COMBINED
A
B
Facades + Acoustics of Exterior Space
63 125 250
500
1K
4K
2K
22.5
45
67.5
90+
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A
SPATIAL RESPONSE
B
COMBINED Sound is not hitting audience area evenly, and is reflecting more strongly off of the eastern wall of Building B.
Facades + Acoustics of Exterior Space
ITERATION I Sound is projecting in a more central location evenly, however the throw distance is not quite far enough to reach the back of the intended audience area.
75
C
D
ITERATION II Here we are seeing better throw distance however there are moments of sporatic distribution and the sound is reflecting more heavily off of the eastern wall of Building B.
BASE CONDITION As this is analyzing the sound coming from the street rather than the intended sound source on the site, it does not directly compare to the previous spatial diagrams. It does, however, show the high intensity of the street and train noise and the overall impact on the outdoor site. It particularly impacts the northwestern corner of Building A and encourages the facade geometry to extend out in this area and block some of the sound penetrating the site. Victoria Brown
With the base conditions, you are able to see sound intensities closely restrained to the sound source.
A
The sound intensity levels are increasing and expanding in throw distance out into the audience area. Levels between 45 and 67.5dB
B
The sound intensity levels remain constant but increase in throw distance to the end of the audience area.
C
22.5
45
67.5
Facades + Acoustics of Exterior Space
90+
77
OVERALL dB ON SITE DIRECT SOUND BACKGROUND NOISE
BASE CONDITIONS
ITERATION I
ITERATION II 0
50
100
ENERGY LOSS A
84%
B
67%
C
39%
Offered through the Pachyderm Acoustic Plug-in, as the sound is mapped on the site there is a degree to which the sound dissipates in the open-air site. Here, you can see the sound energy that immediately leaves the site as the source emits it. The final iteration retains 45% more sound than the base condition without an acoustical facade. Victoria Brown
Facades + Acoustics of Exterior Space
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