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Guidelines for Airport Sound Insulation Programs (2013)

Chapter: Chapter 6 - Treatment of Historic Structures

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Page 106
Suggested Citation:"Chapter 6 - Treatment of Historic Structures." National Academies of Sciences, Engineering, and Medicine. 2013. Guidelines for Airport Sound Insulation Programs. Washington, DC: The National Academies Press. doi: 10.17226/22519.
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Suggested Citation:"Chapter 6 - Treatment of Historic Structures." National Academies of Sciences, Engineering, and Medicine. 2013. Guidelines for Airport Sound Insulation Programs. Washington, DC: The National Academies Press. doi: 10.17226/22519.
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Suggested Citation:"Chapter 6 - Treatment of Historic Structures." National Academies of Sciences, Engineering, and Medicine. 2013. Guidelines for Airport Sound Insulation Programs. Washington, DC: The National Academies Press. doi: 10.17226/22519.
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Suggested Citation:"Chapter 6 - Treatment of Historic Structures." National Academies of Sciences, Engineering, and Medicine. 2013. Guidelines for Airport Sound Insulation Programs. Washington, DC: The National Academies Press. doi: 10.17226/22519.
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Suggested Citation:"Chapter 6 - Treatment of Historic Structures." National Academies of Sciences, Engineering, and Medicine. 2013. Guidelines for Airport Sound Insulation Programs. Washington, DC: The National Academies Press. doi: 10.17226/22519.
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Suggested Citation:"Chapter 6 - Treatment of Historic Structures." National Academies of Sciences, Engineering, and Medicine. 2013. Guidelines for Airport Sound Insulation Programs. Washington, DC: The National Academies Press. doi: 10.17226/22519.
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Page 111
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Suggested Citation:"Chapter 6 - Treatment of Historic Structures." National Academies of Sciences, Engineering, and Medicine. 2013. Guidelines for Airport Sound Insulation Programs. Washington, DC: The National Academies Press. doi: 10.17226/22519.
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Page 113
Suggested Citation:"Chapter 6 - Treatment of Historic Structures." National Academies of Sciences, Engineering, and Medicine. 2013. Guidelines for Airport Sound Insulation Programs. Washington, DC: The National Academies Press. doi: 10.17226/22519.
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Suggested Citation:"Chapter 6 - Treatment of Historic Structures." National Academies of Sciences, Engineering, and Medicine. 2013. Guidelines for Airport Sound Insulation Programs. Washington, DC: The National Academies Press. doi: 10.17226/22519.
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106 The spirit and direction of the Nation are founded upon and reflected in its historic heritage. The historic and cultural foundations of the Nation should be preserved as a living part of our community life and development in order to give a sense of orientation to the American people. — Section 1 of the National Historic Preservation Act Acknowledging the architectural and historical character of significant buildings is an important part of a sound insulation program’s ability to engender community goodwill. Further, sponsors of sound insulation programs are obligated per AIP grant assurances to certify that the project will “comply with all applicable Federal laws . . . as they relate to . . . the use of Federal funds for the project.”1 The National Historic Preservation Act of 1966 is one of the regulatory requirements airport sponsors certify compliance with when accepting AIP grant funding. Section 106 of the act specifically addresses the protection of historic proper- ties. An understanding of the act and its associated regulations (particularly 38 CFR Part 800) is important not only to ensure that the sponsor is in compliance with grant funding require- ments, but to ensure the preservation of significant historic resources that have meaning and value to the community.2 6.1 The Role of Section 106 The purpose of Section 106 is to identify historic properties potentially affected by federally funded projects and seek ways to avoid, minimize, or mitigate any adverse effects to them. The adverse effect usually associated with a sound insulation program is described by 36 CFR 800.5(a)(2)(ii): Alteration of a property, including restoration, rehabilitation, repair, maintenance, stabilization, hazard- ous material remediation, and provision of handicapped access, that is not consistent with the Secretary’s Standards for the Treatment of Historic Properties (36 CFR Part 68) and applicable guidelines.3 Specific to sound insulation programs, airport sponsors and the FAA need to comply with Section 106 and its associated regulation, 38 CFR Part 800, to take into account potential effects of sound insulation treatments on structures that are either listed in the National Register of His- toric Places (“National Register”) or meet eligibility criteria for listing in the National Register. The Section 106 process allows for review and consultation between project stakeholders and other parties with an interest in the effects of the project on historic properties. This consulta- C H A P T E R 6 Treatment of Historic Structures 1 Airport Sponsor Assurances, FAA, last modified March 2011, http://www.faa.gov/airports/aip/grant_assurances/media/airport_ sponsor_assurances.pdf. 2 36 CFR Part 800 – Protection of Historic Properties (incorporating amendments effective August 5, 2004, Advisory Council on Historic Preservation, accessed November 2011, http://www.achp.gov/regs-rev04.pdf. 3 36 CFR Part 800 – Protection of Historic Properties (incorporating amendments effective August 5, 2004, Advisory Council on Historic Preservation, accessed November 2011, http://www.achp.gov/regs-rev04.pdf.

Treatment of Historic Structures 107 tion should take place during the start-up phase of the project before the design and installa- tion of sound insulation treatments begin. 6.2 Definition of Historic The National Register Bulletin states that “[t]he quality of significance in American history, architecture, archeology, engineering, and culture is present in districts, sites, buildings, structures, and objects that possess integrity of location, design, setting, materials, workmanship, feeling, and association.”4 Of these various types of historic resources, sound insulation programs deal with buildings or groupings of buildings that individually or as a “district” (a group of buildings with similar architectural or historic characteristics) can be considered historic by local communities, states, or the federal government. Per AIP grant assurances, sound insulation programs need to determine if any of the structures that are eligible for treatment are considered to be historic. Per evaluation criteria established by the Secretary of Interior for listing in the National Register, a structure is considered eligible if one or more of the following criteria are met: Criterion A. Buildings associated with events that have made a significant contribution to the broad patterns of U.S. history; or Criterion B. Buildings associated with the lives of significant persons in our past; or Criterion C. Buildings that embody the distinctive characteristics of a type, period, or method of construction, or that represent the work of a master, or that possess high artistic values, or that represent a significant and distinguishable entity whose components may lack individual distinction; or Criterion D. Buildings that have yielded, or may be likely to yield, information important in history or prehistory.5 Exceptions to the criteria: buildings with attributes noted in the following are not ordinarily considered eligible for the National Register: • Buildings owned by religious institutions or used for religious purposes, • Buildings that have been moved from their original locations, • Reconstructed historic buildings, • Buildings that are primarily commemorative in nature, • Buildings less than 50 years old,6 and • Buildings with insufficient integrity. 6.3 The Section 106 Process The Section 106 process should be undertaken during the start-up phase of a sound insulation program to determine: • If any of the buildings designated for sound insulation are historic, • If sound insulation treatments will affect those historic properties, and • If the effect of sound treatments is deemed adverse. 4 “How to Apply the National Register Criteria for Evaluation,” National Register Bulletin, National Park Service, accessed November 2011, http://www.nps.gov/nr/publications/bulletins/nrb15/nrb15_2.htm. 5 Adapted from “How to Apply the National Register Criteria for Evaluation,” National Register Bulletin, National Park Ser- vice, accessed November 2011, http://www.nps.gov/nr/publications/bulletins/nrb15/nrb15_2.htm. 6 Adapted from “How to Apply the National Register Criteria for Evaluation,” National Register Bulletin, National Park Ser- vice, accessed November 2011, http://www.nps.gov/nr/publications/bulletins/nrb15/nrb15_2.htm.

108 Guidelines for Airport Sound Insulation Programs If adverse effects are determined, establish measures required to mitigate them. As indicated in the process diagram shown in Figure 6.1, there are four distinct steps to the 106 process:7 1. Initiation of the 106 process and identification of participants, 2. Identification of historic properties, 3. Assessment of adverse effects, if any, and 4. Resolution of adverse effects: memorandum of agreement or programmatic agreement. A brief description of each of the four steps follows. Section 106 Overview 1. Initiate Section 106 Process Establish undertaking Identify consulting parties 2. Identify Historic Properties Determine scope of efforts Identify historic properties Evaluate historic significance 3. Assess Adverse Effects Apply criteria of adverse effect 4. Resolve Adverse Effects Undertaking might affect historic properties Historic properties are identified Historic properties are adversely affected Programmatic Agreement or Memorandum of Agreement If no historic properties are adversely affected If no undertaking or if no potential to cause effects Then, Agreement of No Adverse Effect is issued Then, 106 process is concluded Figure 6.1. The four steps of the Section 106 process. 7 Historic Preservation: Section I, Surface Transportation Board, accessed November 2011, http://www.stb.dot.gov/stb/ environment/HistoricPreservation/Section1.htm.

Treatment of Historic Structures 109 6.3.1 Step 1: Initiation of the Section 106 Process and Identification of Participants The responsibility for the Section 106 process lies with the FAA.8 However, this responsibility can be (and usually is) passed to the airport sponsor as the grantee of federal funds. Whether the FAA or the airport sponsor assumes responsibility for the 106 process, this party becomes the responsible agency for coordinating the 106 process and includes all stakeholders who will potentially be affected by the project. As a best practice, these consulting parties should include: • Regional FAA project manager or point of contact, • Representative(s) of the airport sponsor (airport owner/sound insulation manager/sponsor’s consultant), • State historic preservation officer (SHPO), • Tribal historic preservation officer, if applicable, • City historic preservation officer, if applicable, • Representative(s) of native Hawaiian organization, if applicable, • Representative(s) of national Advisory Council on Historic Preservation (ACHP), as required, and • Representative(s) of local public historic preservation commission, if applicable. The agency first determines whether it has an undertaking that is a type of activity that could affect historic properties. If it determines its undertaking is a type of activity that has no potential to affect historic properties, the agency has no further Section 106 obligations. Note: An undertaking as defined by the 106 process refers to a project, activity, or program funded in whole or in part under the direct or indirect jurisdiction of a federal agency, includ- ing those carried out by or on behalf of a federal agency, those carried out with federal financial assistance, and those requiring a federal permit, license, or approval. 9 6.3.2 Step 2: Identification of Historic Properties10 If the agency’s undertaking could affect historic properties, the agency determines the scope of appropriate identification efforts and proceeds to identify historic properties in the area of potential effects (APE). The APE refers to the geographic area or areas within which an under- taking may directly or indirectly cause alterations in the character or use of historic properties, if any such properties exist. The APE is influenced by the scale and nature of an undertaking. For sound insulation programs, the APE is the geographic area that is within the program boundary. The agency reviews background information, holds discussions with the consulting parties, seeks information from knowledgeable parties, and conducts additional studies as necessary. Districts, sites, buildings, structures, and objects listed in the National Register are considered; unlisted properties are evaluated against the Secretary of Interior’s published criteria, in consul- tation with the SHPO. If questions arise about the eligibility of a given property, the agency may seek a formal determination of eligibility from the ACHP. A Section 106 review gives equal consideration to properties that have already been included in the National Register as well as those that have not been so included but meet National Reg- ister criteria. If the agency finds that no historic properties are present or affected, it provides 8 See note 2. 9 16 USC § 470w : US Code - Section 470W: Definitions, Find Law, accessed November 2011, codes.lp.findlaw.com/uscode/16/1A/ II/C/470w. 10 See note 2.

110 Guidelines for Airport Sound Insulation Programs documentation to the SHPO and, barring any objection in 30 days, proceeds with its undertaking. If the agency finds that historic properties are present, it proceeds to assess possible adverse effects. 6.3.3 Step 3: Assessment of Adverse Effects11 The agency, in consultation with the other stakeholders, makes an assessment of adverse effects on the identified historic properties based on criteria found in the regulations. If they agree that there will be no adverse effects, the agency proceeds with the undertaking and any agreed-upon conditions. An agreement of no adverse effect (NAE) is documented to formally acknowledge this finding. If they find that there is an adverse effect, or if the parties cannot agree on the solution to reduce adverse effects, the agency begins consultation to seek ways to avoid, minimize, or mitigate the adverse effects. 6.3.4 Step 4: Resolution of Adverse Effects: Memorandum of Agreement and Programmatic Agreement To resolve adverse effects, the agency confers with the consulting stakeholders. The ACHP may participate in consultation when there are substantial impacts to important historic properties, when a case presents important questions of policy or interpretation, when there is a potential for procedural problems, or when there are issues of concern to Indian tribes or native Hawaiian organizations. Consultation usually results in a memorandum of agreement (MOA) or pro- grammatic agreement (PA), which outlines agreed-upon measures that the agency will take to avoid, minimize, or mitigate the adverse effects. In some cases, the consulting parties may agree that no such measures are possible but that the adverse effects must be accepted in the public interest. 6.4 Preparing Agreement Documents (NAEs, MOAs, PAs) There are three types of agreement documents that record the outcome of the Section 106 process: NAEs, MOAs, and PAs.12 It is important that every sound insulation program have the result of its 106 process recorded in one of these three documents. A brief description of each document follows. No Adverse Effect. Given the number of structures that are typically treated in sound insu- lation programs, it would be highly unusual for there to be no historically significant structures or for none of the program treatments to result in an adverse effect. However, should this be the case, the finding of NAE, or declaration of measures the program will take to avoid adverse effect, is recorded in an NAE agreement signed by the FAA, SHPO, the airport sponsor, and, as relevant, the appropriate local public historic agency. The council is typically advised of the NAE and provided with supporting documentation that substantiates the finding. Memorandum of Agreement. An MOA records the outcome of a 106 process where there is no reasonable alternative to the action causing the adverse effect and where the measures that can be adopted to reduce or mitigate the adverse effects are obvious and easily agreed on. In these cases, an MOA is appropriate and represents the best compromise to all consulting parties. 11 See note 2. 12 Excerpted from Preparing Agreement Documents: How to Write Determination of No Adverse Effect, Memoranda of Agree- ment, and Programmatic Agreements Under 36 CFR Part 800, Advisory Council on Historic Preservation, September 1989.

Treatment of Historic Structures 111 Programmatic Agreement. A PA is the preferred agreement document to use when there is a large and complex program that would require many individual requests for consultation of adverse effect and where making such requests will be inefficient. Treatment guidelines describ- ing typical treatments and mitigation measures are usually part of a PA. The participants and signatories to a PA are almost always the FAA, SHPO, the airport sponsor, the local government historic agency, and the council. Further information regarding these three agreement documents can be found in Preparing Agreement Documents: How to Write Determination of No Adverse Effect, Memoranda of Agree- ment, and Programmatic Agreements Under 36 CFR Part 800, issued by the ACHP. 6.5 Sound Insulating Historic Structures 6.5.1 Diversity of Historic Structures The types of structures that are potentially historic cover hundreds of years of American history and a wide-ranging variety of architectural styles. Some of these styles, such as Pueblo, California Mission, Colonial, and Federal, are regional responses to cultural influences and con- struction techniques and materials that were unique to the geographic region in which they originated. Many different types of windows, doors, and wall and roof conditions were created in response to these same regional factors. The challenge of providing acoustical treatments and products appropriate to these diverse styles and material conditions is daunting but is necessary given the need to mitigate adverse impacts to historic properties. 6.5.2 Design Process and Limitations The treatment guidelines developed for the PA must conform to the Secretary of the Interior’s Standards for Treatment of Historic Properties. The Secretary of the Interior is responsible for establishing standards for all federally funded programs. The standards describe four separate treatment approaches: preservation, rehabilitation, restoration, and reconstruction. The Stan- dards for Rehabilitation (36 CFR Part 67) are the most relevant to developing treatments for sound insulation programs. Rehabilitation is defined as: the process of returning a property to a state of utility through repair or alteration which makes pos- sible an efficient contemporary use while preserving those portions and features of the property which are significant to its historic, architectural, and cultural values.13 Three levels of treatment are described by the rehabilitation standards: 1. Protecting and maintaining. This generally involves the least degree of intervention and is preparatory to other work. For example, protection includes the “maintenance of historic materials through treatments such as rust removal, caulking, limited paint removal, and reap- plication of protective coatings; the cyclical cleaning of roof gutter systems; or installation of fencing, alarm systems, and other temporary protective measures.”14 2. Repair. Recommended “when the physical condition of character-defining materials and features warrant additional work. . . . Rehabilitation guidance for the repair of historic materials . . . begins with the least degree of intervention possible such as patching, piecing-in, splicing, consolidating, or otherwise reinforcing or upgrading them according to recognized 13 The Secretary of the Interior’s Standards for Rehabilitation, National Park Service, accessed November 2011, www.nps.gov/ tps/standards/rehabilitation/rehab/stand.htm. 14 Excerpted from, Anne E. Grimmer and Kay D. Weeks, Secretary of the Interior’s Standards for the Treatment of Historic Properties, (Washington, D.C.: U.S. Department of the Interior, 1995), 63.

112 Guidelines for Airport Sound Insulation Programs preservation methods. Repairing also includes the limited replacement like-for-like—or with compatible substitute material—of extensively deteriorated or missing parts of features when there are surviving prototypes. . . . Although using the same kind of material is always the preferred option, substitute material is acceptable if the form and design as well as the substitute material itself convey the visual appearance of the remaining parts of the feature and finish.”15 3. Replacement with new material. Sometimes required when “the level of deterioration or damage of materials precludes repair. . . . Like the guidance for repair, the preferred option is always replacement of the entire feature like-for-like, that is, with the same material. Because this approach may not always be technically or economically feasible, provisions are made to consider the use of a compatible substitute material.”16 Designing appropriate sound insulation treatments for historic buildings begins with iden- tifying the character-defining features of the historic building that is being evaluated for treat- ment. Character-defining features include specific elements of the building evidenced in the architectural design, materials, and workmanship, and items that contribute to its historic feel- ing. Particularly important to sound insulation programs are character-defining features such as windows, doors, and roofs, and other exterior envelope features that may be affected by sound insulation treatments. 6.5.3 Historic Treatment Priorities A strict application of the Standards for Rehabilitation and the three levels of treatment as discussed in the previous section suggests there are three options for sound insulation treatments of windows, doors, and other treatments visible from the public right-of-way.17 • Option one: maintain existing conditions. • Option two: maintain and upgrade existing windows and doors. • Option three: replace existing materials with acoustical products. Option one, maintaining existing conditions, is not a viable option for sound insulation pro- grams where noise infiltrates into the structure by virtue of deficiencies in the exterior envelope, with the greatest noise paths being windows and doors. Option two, maintaining and upgrading existing windows and doors, can sometimes be an option depending on many factors, including location of the structure within the contour, condi- tions of the doors and windows, and the degree to which the windows and doors need to be acous- tically improved in order to meet program acoustical goals. The program architect and acoustical consultant should consult closely to determine if treatments per option two are possible. Option three, replacing existing materials, is the option most often pursued by sound insula- tion programs. As a practical matter, reducing noise levels by at least 5 dB and achieving an inte- rior noise level of not greater than DNL 45 dB are often not possible without replacing existing windows and doors. It is important to note, however, that research needs to be done and care needs to be taken when specifying replacement window and door products. 15 Excerpted from, Anne E. Grimmer and Kay D. Weeks, Secretary of the Interior’s Standards for the Treatment of Historic Properties, (Washington, D.C.: U.S. Department of the Interior, 1995), 63. 16 Excerpted from, Anne E. Grimmer and Kay D. Weeks, Secretary of the Interior’s Standards for the Treatment of Historic Properties, (Washington, D.C.: U.S. Department of the Interior, 1995), 63. 17 Secretary of the Interior’s Standards for Rehabilitation, California Department of Parks and Recreation, April 27, 2011, www.parks.ca.gov/pages/1054/files/santa%20clara%20stdsc.pdf.

Treatment of Historic Structures 113 Provision number 6 of the Standards for Rehabilitation states that when a historic feature needs to be replaced, “the new feature shall match the old in design, color, texture, and other visual qualities and, where possible, materials.”18 Note that some regional FAA offices have relaxed the requirement that a 5-dB NLR be achieved in some cases where the historic integrity of a structure would be irreversibly compromised by replacement of windows or doors. PGL 12-09 does not mention whether an exception to the FAA’s stated acoustical goals (i.e., minimum 5-dB NLR improvement and interior noise level of not greater than DNL 45 dB) will be allowed if treatments required to meet these goals are prohibited by a PA or MOA. Program sponsors and consultants are advised to consult with their local ADO before treating any historic structure(s). There are of course other acoustical treatments typical to sound insulation projects that can visually affect a historic structure. When planning for installation of mechanical and electrical equipment, rooftop vents, wall vents, chimney caps, and so forth, care should be taken to, where possible, place such equipment in locations that are not visible from the public right-of-way. As noted in Section 6.4, MOAs and PAs typically include treatment guidelines that specifi- cally describe the preferred options for rehabilitation, the process for reviewing and approving changes to character-defining features of historic structures, and the types of products that are permitted for upgrading and replacing historic materials. It is a best practice for every program to have worked with local, state, and, as necessary, national historic preservation agencies to pre- pare historic treatment guidelines. These guidelines act as the rulebook that defines what is and what is not appropriate for acoustical treatment, which can help avoid painstaking and expensive structure-by-structure reviews and misunderstandings as to what treatments are permissible and under what circumstances. 6.5.4 Building Codes Historic structures can be exempt from complying with some aspects of the building code, but generally not those provisions that directly affect the health and safety of occupants. Building codes will often define which types of historic structures are exempt from certain code provi- sions. These exemptions typically apply to house-museum type structures and not those historic structures that are ordinarily eligible for listing on local, state, or national registers. A best prac- tice for consultants and sponsors alike is to consult with the building officials who have juris- diction over the program area to review which code provisions apply to the program’s historic structures. One such health/safety code provision that is rarely exempted for historic structures is the requirement that any room used for sleeping purposes must have a minimum of one opening that can be used for emergency egress. When this opening is a window, the architect needs to ensure that the window meets the minimum size required by code. Often, meeting these mini- mum size requirements requires either changing the style of the window or its size. Both of these alterations can affect the historic appearance of the structure, and such changes need to be care- fully considered. It is also important to note that some building codes require at least one egress door to meet minimum size requirements as well. These situations present the same need to carefully consider the style and material of the new door if replacement is required. 18 Technical Preservation Services, Interpreting the Standards, Number 23, (Washington, D.C.: National Park Service, 2001).

114 Guidelines for Airport Sound Insulation Programs Designers and sponsors need to be aware of the impacts that energy codes presently have and will increasingly have on door and window products. As codes become increasingly strin- gent in their requirements for energy performance, finding window and door products that are appropriate to treat historic structures will become more difficult. For example, low-E glass is now almost universally required to meet the energy requirements for windows. However, most historic commissions do not allow it to be used in historic structures due to its non-historic appearance. (Many types of low-E glass have a slight off-color tint and reflective qualities.) It can be expected that the sometimes competing requirements of energy efficiency and preserva- tion of architectural features of historic structures will increasingly need to be considered when specifying products and treatments for sound insulation programs. 6.6 Best Practice Recommendations: Treatment of Historic Structures 1. To ensure a thorough and appropriate consultation between project stakeholders and other parties with an interest in the effects of the project on historic properties, undertake and complete the Section 106 process during the start-up phase of the project, before the design and installation of sound treatments begin. 2. Be sure to include all relevant consulting parties, as listed in Section 6.3.1. 3. Record the result of the 106 process in an NAE, MOA, or PA, as appropriate. 4. Treatment guidelines developed for a PA must conform to the Secretary of the Interior’s Standards for Treatment of Historic Properties. 5. Work with local, state, and, as necessary, national historic preservation agencies to prepare historic treatment guidelines. 6. Consultants and sponsors alike should consult with building officials who have juris- diction over the program area to review which code provisions apply to the program’s historic structures. 7. Consult with the local FAA ADO to determine if an exception to the FAA’s stated acoustical goals will be allowed if treatments required to meet these goals are pro- hibited by a PA or MOA. 8. Be aware of the sometimes competing requirements of energy efficiency and pres- ervation of architectural features of historic structures when specifying products and treatments for sound insulation programs.

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TRB’s Airport Cooperative Research Program (ACRP) Report 89: Guidelines for Airport Sound Insulation Programs provides updated guidelines for sound insulation of residential and other noise-sensitive buildings. The report is designed to help airports and others develop and effectively manage aircraft noise insulation projects.

In February 2014 TRB released ACRP Report 105: Guidelines for Ensuring Longevity of Airport Sound Insulation Programs, which complements ACRP Report 89.

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