Item 23 - First One -Year Extension for Site Plan Review No. 2020-03 and Variance No. 2020-06

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Eilar Associates, Inc. Acoustical and Environmental Consulting Services floor/ceiling assemblies, and an added requirement dictates that the Impact Insulation Class (IIC) rating of the floor/ceiling assembly is a minimum laboratory rating of IIC 50. Further details regarding the evaluation of common wall and floor/ceiling assemblies are provided in Appendix E. The limitations and general recommendations listed in this section should also be taken into account in the construction of this building. Some assembly ratings were obtained from the California Department of Health Services Office of Noise Control Catalog of STC and IIC Ratings for Wall and Floor/Ceiling Assemblies (see reference), hereafter referred to as "Catalog." Wall Assemblies Wood -Framed One Hour -Bated Wall at Corridor (2/AD 22) In some locations where residential units are located adjacent to corridors, the following assembly is proposed: • Single layer of 5/8-inch-thick Type X gypsum board • 2-inch by 4-inch wooden studs, staggered on a 6-inch (minimum) bottom plate, spaced at 16 inches on -center • Fiberglass batt insulation in each cavity • Single layer of 5/8-inch-thick Type X gypsum board A laboratory STC test of this assembly was conducted by Owens Corning (Catalog section number 1.2.3.1.5.3) and achieved an STC rating of 46, which does not meet the California Building Code requirement for a minimum STC rating of 50. Therefore, the wood -framed one -hour corridor wall should be improved as follows: Impmved Wood -Framed One -Hour -Rated Wall at Corridor (2/AD-22) • Double layer of 5/8-inch-thick Type X gypsum board (inner layer can be replaced with plywood where required for shear) • 2-inch by 4-inch wooden studs, staggered on a 6-inch (minimum) bottom plate, spaced at 16 inches on -center • Fiberglass batt insulation in each cavity • Single layer of 5/8-inch-thick Type X gypsum board A laboratory test was performed by the National Research Council of Canada (test number T1-93- 226) for this wall assembly and achieved an STC rating of 52 and is therefore expected to meet the California Building Code requirement for a minimum STC rating of 50. Wood -Framed One -Hour -Rated Pary Wall (3/AD 22) In some locations where residential units are located adjacent to one another, the following assembly is proposed: • Single layer of 5/8-inch thick Type X gypsum board • Double row of 2-inch by 4-inch wooden studs, spaced at 16 inches on -center, separated by 1-inch gap • Fiberglass batt insulation in each cavity • Single layer of 5/8-inch thick Type X gypsum board Acoustical Analysis Report for 4th and Mortimer • Job # S220404 • July 18, 2022 Page 12 Eilar Associates, Inc. Acoustical and Environmental Consulting Services A laboratory test was performed by Riverbank Acoustical Labs (Catalog Section 1.2.4.1.5.4) for this wall assembly. The tested assembly achieved an STC rating of 57 and is therefore expected to meet the California Building Code requirement for a minimum STC rating of 50. The addition of layers of gypsum board on either side of the assembly is expected to increase the overall rating; therefore, where a double layer of gypsum board is used on one or both sides of the parry wall (such as with the two-hour rated party wall [7/AD-221), the STC rating of the assembly would exceed STC 57. Metal -Framed One -Hour -Rated Par y Wall (11 /AD 22) In some locations where residential units are located adjacent to one another, the following assembly is proposed: • Double layer of 5/8-inch thick Type X gypsum board • Double row of 3-5/8-inch studs, spaced at 16 inches on -center, separated by 1-inch gap • Fiberglass batt insulation in each cavity • Single layer of 5/8-inch thick Type X gypsum board No specific sound test was available for this exact configuration; however, the above assembly was evaluated using INSUL, and was shown to have an STC rating of 65, which meets the California Building Code requirement for a minimum STC rating of 50. The addition of layers of gypsum board on either side of the assembly is expected to increase the overall rating; therefore, where a double layer of gypsum board is used on both sides of the parry wall (such as with the two -hour -rated parry wall [15/AD-22]), the STC rating of the assembly would exceed STC 65. Three -Hour -Rated Fire Wall (1 /AD-25) The three-hour fire wall is proposed to be constructed as follows: • Single layer of 5/8-inch-thick Type X gypsum board • Single layer of plywood sheathing (where occurs) • Single row of 2-inch by 4-inch wooden studs, spaced at 16 inches on -center • Air gap, with fiberglass insulation in the air cavity • Single layer of 1-inch-thick Type X gypsum board • Single row of 2-1/2-inch CH studs, spaced at 16 inches on -center • Triple layer of 5/8-inch-thick Type X gypsum board • Air gap, with fiberglass insulation in the air cavity • Single row of 2-inch by 4-inch wooden studs, spaced at 16 inches on -center • Single layer of 5/8-inch-thick Type X gypsum board No specific sound test was available for this exact configuration; however, the interior three -hour -rated core stud with one side of the wood -framed furring wall assembly was evaluated using INSUL and was shown to have an STC rating of 66. Due to the complexity of the overall assembly, the entire assembly could not be evaluated using INSUL, and therefore the contribution that the other wood -framed furring wall assembly would have on the STC rating of the overall assembly could not be evaluated. However, the addition of the wood - framed furring walls is not expected to increase the STC rating of the assembly significantly, and therefore, a conservative STC rating of the above assembly is STC 66. This assembly is expected to comply with the minimum STC requirements of the California Building Code as currently designed. Acoustical Analysis Report for 4th and Mortimer • Job # S220404 • July 18, 2022 Page 13 Eilar Associates, Inc. Acoustical and Environmental Consulting Services 5.2 Interior 5.2.1 Transportation Noise Sources DWellinLr Units The State of California and the City of Santa Ana require buildings to be designed in order to attenuate, control, and maintain interior noise levels not greater than 45 CNEL in habitable space, as formulated in the City of Santa Ana. Noise Element to the General Plan and the California Building Code, Section 1206.4. According to the U.S. EPA (see reference), current exterior building construction is generally expected to achieve at least 15 decibels of exterior -to -interior noise attenuation with windows opened. Therefore, proposed project building structures exposed to exterior noise levels greater than 60 CNEL could be subject to interior noise levels exceeding the 45 CNEL noise limit for residential habitable space. As exterior noise levels at most building facades exceed 60 CNEL, an exterior -to -interior analysis was performed for representative units to determine design considerations required to maintain compliant interior noise levels. The typical exterior wall assembly is proposed to be constructed as a 2-inch by 6-inch wood -framed assembly with stucco on the exterior, insulation in the cavity, and one layer of 5/8-inch thick Type X gypsum board on the interior. The typical exterior wall assembly was evaluated using INSUL and was shown to achieve an STC rating of 38. Please refer to Appendix E for additional information. The results of the exterior -to -interior noise analysis for interior habitable spaces are shown in Table 7, with acoustical recommendations made therein. For more information, please refer to Appendix F: Exterior -to - Interior Noise Analysis. Table 7. Interior Noise Levels of Representative Units Room Type Maximum Exterior Facade Impact (CNEL) STC Rating for Glazing Interior Noise Level (CNEL) Windows/ Doors Open Windows/ Doors Closed Living / Kitchen / Dining 72 28 60 42 Bedroom 72 28 61 41 As shown above, with proposed exterior walls and exterior glazing with a minimum STC rating of 28, interior noise levels will remain below 45 CNEL in all habitable space with windows and exterior doors closed. The sound rating of exterior glazing should be confirmed with the manufacturer prior to installation to confirm these STC rating requirements will be met. In instances where interior habitable space is exposed to noise levels greater than 45 CNEL with windows in the open position, appropriate means of air circulation and provision of fresh air must be present to allow windows to remain closed for extended intervals of time so that acceptable levels of noise can be maintained on the interior. As exterior noise levels are expected to exceed limits with windows and doors open at all units, mechanical ventilation will be required in all units. The proposed mechanical ventilation system shall meet the criteria of the California Mechanical Code, including the capability to provide appropriate ventilation rates. The ventilation system shall not compromise the sound insulation capability of the exterior wall or be dependent on ventilation through windows. Exterior door installation should include all-around weather -tight door stop seals and an improved threshold closure system. The additional hardware will improve the doors' overall sound reduction properties. The Acoustical Analysis Report for 4th and Mortimer • Job # S220404 • July 18, 2022 Page 10 Eilar Associates, Inc. Acoustical and Environmental Consulting Services transmission loss (TL) of an exterior door without weather -tight seals is largely a factor of sound leakage, particularly at the bottom of the door if excessive clearance is allowed for air transfer. By equipping exterior doors with all-around weather -tight seals and an airtight threshold closure at the bottom, a loss of up to 10 STC points can be prevented. Additionally, it is imperative to seal and caulk between the rough opening and the finished door frame for all doors by applying an acoustically resilient, non -skinning, butyl caulking compound. Sealant application should be as generous as needed to ensure effective sound barrier isolation. The same recommendation applies to any other penetrations, cracks, or gaps through the assembly. The OSI SC175 and the Pecora AC-20 FTR acoustic sound sealants are products specifically designed for this purpose. For additional information on these products, please refer to Appendix G: Recommended Products. The proposed habitable spaces were analyzed for interior noise impacts. With the proposed exterior walls and exterior glazing with a minimum STC rating of 28 in place, interior noise levels will remain below 45 CNEL in all habitable space with windows and exterior doors closed. As exterior noise levels are expected to exceed limits with windows and doors open in all units, mechanical ventilation will be required for all units. With these project design features in place, all interior residential space will comply with City of Santa Ana and California Building Code noise requirements. Nonresidential Snaces CALGreen also requires buildings to be designed in order to attenuate, control, and maintain interior noise levels not greater than 50 dBA LEQ peak hour in nonresidential space. For the purposes of this analysis, dBA LEQ peak hour is considered equivalent to CNEL. According to the U.S. EPA (see reference), current exterior building construction is generally expected to achieve at least 15 decibels of exterior -to -interior noise attenuation with windows opened. Therefore, proposed project building structures exposed to exterior noise levels greater than 65 CNEL could be subject to interior noise levels exceeding the 50 CNEL noise limit for nonresidential habitable space. The typical exterior wall assembly was evaluated as detailed above; proposed windows were evaluated as 1- inch-thick dual -glazed windows, and doors were evaluated as 1/4-inch single pane glass doors for a conservative analysis of standard commercial glazing. Please refer to Appendix E for additional information. The results of the exterior -to -interior noise analysis for worst -case nonresidential spaces are shown in Table 8. For more information, please refer to Appendix F: Exterior -to -Interior Noise Analysis. Table 8. Interior Noise Levels of Nonresidential Space Room Maximum Exterior Facade Interior Noise Level Impact (CNEL) (CNEL) Worst -Case Nonresidential Space 72 41 As shown above, with the anticipated exterior wall assembly and standard commercial gJazing, interior noise levels in nonresidential space will comply with CALGreen requirements. 5.2.2 Unit -to -Unit Noise Transmission Another source of noise that may affect residential units in multi -family buildings is unit -to -unit noise transmission. The California State Building Code Section 1206 requires that the Sound Transmission Class (STC) rating of common wall assemblies separating residential units or separating residential units from common areas have a minimum laboratory rating of STC 50. The same STC requirement applies for Acoustical Analysis Report for 4th and Mortimer • Job # S220404 • July 18, 2022 Page 11 Eilar Associates, Inc. Acoustical and Environmental Consulting Services 5.0 Impacts and Mitigation 5.1 Exterior 5.1.1 Outdoor Use Areas As per the City of Santa Ana Noise Element to the General Plan, exterior noise levels at common outdoor use areas should not exceed 65 CNEL for residential areas. The proposed common outdoor use areas on site include courtyards at both buildings and a roof deck on the seventh floor of Building A. Common outdoor use areas were evaluated to determine if noise levels exceed 65 CNEL. Future combined traffic and rail noise levels for the common outdoor use area are shown in Table 4, and take into account the shielding provided by the proposed buildings on site. Receivers were placed at a height of 3.5 feet above grade, to approximate the height of a seated person. The receiver locations are shown in Figure 7. Table 4. Future Exterior Noise Levels at Common Outdoor Use Areas Receiver Location Noise Limit (CNEL) Exterior Noise Level (CNEL) OUl Building A — 7th Floor Roof Deck 65 56 OU2 Building A — 3rd Floor Courtyard/Pool Deck 65 53 OU3 Building B — Courtyard 65 68 OU4 Building B — Dog Park 65 63 As shown in Table 4, exterior noise levels at the common outdoor use areas are expected to exceed the noise limit of 65 CNEL at the Building B courtyard as currently designed. Therefore, a 4-foot barrier wall was incorporated along the southern boundary of the Building B courtyard to reduce noise levels at outdoor use areas. Please refer to Table 5 for mitigated noise levels at outdoor use areas, and Figure 7 for barrier locations. Table 5. Future Exterior Noise Levels at Common Outdoor Use Areas — with 4-foot Barrier Receiver Location Noise Limit Exterior Noise (CNEL) Level (CNEL) OU3 Building B — Courtyard 65 65 As shown in Table 5, with the 4-foot sound barrier in place along the southern boundary of the Building B courtyard, exterior noise levels at the common outdoor use areas are expected to meet the exterior noise limit of 65 CNEL. A sound attenuation wall should be solid and constructed of masonry, wood, plastic, fiberglass, steel, or a combination of those materials, with no cracks or gaps, through or below the wall. Any seams or cracks must be filled or caulked. If wood is used, it can be tongue and groove and must be at least 7/8-inch thick or have a surface density of at least 3-1/2 pounds per square foot. Where architectural or aesthetic factors allow, glass or clear plastic may be used on the upper portion, if it is desirable to preserve a view. Acoustical Analysis Report for 4th and Mortimer • Job # S220404 • July 18, 2022 5.1.2 Building Facades Page 8 Eilar Associates, Inc. Acoustical and Environmental Consulting Services Future combined traffic and rail noise impacts were calculated for all project building facades. Future noise levels at the building facades are expected to range from 47 CNEL at the courtyard of Building A to 72 CNEL at the south facade of Building B. Calculation results are shown in Table 6, and receiver locations are shown graphically in Figure 8. Table 6. Future Exterior Noise Levels at Building Facades Building Receiver Direction Future Exterior Noise Level (CNEL) Floor 1 Floor 2 Floor 3 Floor 4 Floor 5 Floor 6 Floor 7 F1 West 62 62 63 63 62 62 62 F2 West 70 70 69 68 67 67 66 F3 South 72 71 70 69 68 68 67 F4 South 72 71 70 -- -- -- -- F5 South 72 71 70 69 68 68 67 A F6 East 68 68 68 67 66 66 65 F7 East 65 65 65 65 64 64 63 F8 East 66 66 65 65 64 -- -- F9 North 69 68 67 66 65 -- -- F10 Courtyard -- -- 62 65 64 64 63 F11 Courtyard -- -- 47 52 59 59 59 F12 Courtyard -- -- 62 65 64 64 63 F13 North 68 68 67 67 66 -- -- F14 West 67 67 67 66 66 -- -- F15 West 65 66 66 65 65 -- -- F16 West 64 65 65 65 65 -- -- F17 West 70 69 69 68 68 -- -- B F18 South 72 71 70 69 68 -- -- F19 Courtyard 69 69 68 68 67 -- -- F20 Courtyard 65 66 66 66 65 -- -- F21 Courtyard 69 69 68 68 67 -- -- F22 South 72 71 70 69 68 -- -- F23 East 68 68 68 68 67 -- -- F24 East 64 65 65 65 65 -- -- Acoustical Analysis Report for 4th and Mortimer • Job # S220404 • July 18, 2022 Page 9 Eilar Associates, Inc. Acoustical and Environmental Consulting Services 4.1.3 Roadway Noise Calculation The Traffic Noise Model (TNM) calculation protocol in CadnaA Version 2022 (based on the methodology used in TNM Version 2.5, released in February 2004 by the U.S. Department of Transportation) was used for all traffic modeling in the preparation of this report. Using the TNM protocol, the CNEL is calculated as 9.2% of the ADT for surrounding roadways, based on the studies made by Wyle Laboratories (see reference). Future CNEL is calculated for desired receptor locations using future road alignment, elevations, lane configurations, projected traffic volumes, estimated truck mixes, and vehicle speeds. Noise attenuation methods may be analyzed, tested, and planned with TNM, as required. In order to determine the estimated traffic volumes of roadways during the traffic noise measurement made on site for model calibration, the approximate percentage of the Average Daily Trips (ADT) value for the time period in which the measurement is made is incorporated into the traffic model. These percentages were established in a study performed by Katz-Okitsu and Associates, Traffic Engineers (see reference). For purposes of calibrating the CadnaA TNM, 5.3% of the ADT values for the current environment were used in calculations (for roadways that were not manually counted) to account for traffic between the hours of 10 a.m. and 11 a.m. in the vicinity of the project site. 4.1.4 Exterior -to -Interior Noise Analysis The State of California and the City of Santa Ana require buildings to be designed in order to attenuate, control, and maintain average interior noise levels not greater than 45 CNEL in residential space, as formulated in the California Building Code, Section 1206.4 and the City of Santa Ana Noise Element to the General Plan. Contemporary exterior building construction is expected to achieve at least 15 decibels of exterior -to -interior noise attenuation with windows opened, according to the U.S. Environmental Protection Agency Office of Noise Abatement and Control (see reference). As a result, exterior noise levels of more than 60 CNEL often result in interior conditions that fail to meet the 45 CNEL requirements for habitable space. Analysis for the interior noise levels requires consideration of: • Number of unique assemblies in the wall (doors, window/wall mount air conditioners, sliding glass doors, and windows) • Size, number of units, and sound transmission data for each assembly type • Length of sound impacted wall(s) • Depth of sound impacted room • Height of exterior wall of sound impacted room • Exterior noise level at wall assembly or assemblies of sound impacted room The Composite Sound Transmission data is developed for the exterior wall(s), and the calculated noise exposure is converted to octave band sound pressure levels (SPL) for a typical traffic type noise. The reduction in room noise due to absorption is calculated and subtracted from the interior octave noise levels, and the octave band noise levels are logarithmically summed to yield the overall interior room noise level. When interior noise levels exceed 45 CNEL, the noise reduction achieved by each element is reviewed to determine which changes will achieve the most cost-effective compliance. Windows are usually the first to be reviewed, followed by exterior doors, and then exterior walls. Modeling of wall assemblies is accomplished using INSUL Version 9.0, which is a model -based computer program, developed by Marshall Day Acoustics for predicting the sound insulation of walls, floors, ceilings, and windows. It is acoustically based on theoretical models that require only minimal material information that can make reasonable estimates of the sound transmission loss (TL) and STC for use in sound insulation calculations, such as the design of common parry walls and multiple family floor -ceiling assemblies, etc. INSUL Acoustical Analysis Report for 4th and Mortimer • Job # S220404 • July 18, 2022 Page 6 Eilar Associates, Inc. Acoustical and Environmental Consulting Services can be used to quickly evaluate new materials or systems or investigate the effects of changes to existing designs. It models individual materials using the simple mass law and coincidence frequency approach and can model more complex assembly partitions, as well. It has evolved over several versions into an easy to use tool and has refined the theoretical models by continued comparison with laboratory tests to provide acceptable accuracy for a wide range of constructions. INSUL model performance comparisons with laboratory test data show that the model generally predicts the performance of a given assembly within 3 STC points. IIC predictions are generally made based on laboratory tests from a number of resources, including third -party test data provided by product manufacturers and National Research Council of Canada test results. 4.1.5 Sound Transmission Class (STC) and Impact Insulation Class (IIC) Ratings Sound Transmission Class (STC) is a single number rating calculated in accordance with ASTM E413, using third -octave values of sound transmission loss. It provides an estimate of the sound performance of a partition, window, or door in sound insulation problems. Likewise, Impact Insulation Class (IIC) is a single number rating calculated in accordance with ASTM E989 that is used to describe the transmission of impact noise through floor/ceiling assemblies, caused primarily by footsteps from one space to another. Modeling of wall and floor/ceiling assemblies is accomplished using INSUL Version 9.0, which is a model - based computer program, developed by Marshall Day Acoustics for predicting the sound insulation of walls, floors, ceilings, and windows. It is acoustically based on theoretical models that require only minimal material information that can make reasonable estimates of the sound transmission loss (TL), STC, and IIC for use in sound insulation calculations, such as the design of common party walls and multiple family floor -ceiling assemblies, etc. INSUL can be used to quickly evaluate new materials or systems or investigate the effects of changes to existing designs. It models individual materials using the simple mass law and coincidence frequency approach and can model more complex assembly partitions, as well. It has evolved over several versions into an easy to use tool and has refined the theoretical models by continued comparison with laboratory tests to provide acceptable accuracy for a wide range of constructions. INSUL model performance comparisons with laboratory test data show that the model generally predicts the performance of a given assembly within 3 STC points. IIC predictions are generally made based on laboratory tests from a number of resources, including third -party test data provided by product manufacturers and National Research Council of Canada test results. 4.2 Measurement Equipment Some or all of the following equipment was used at the site to measure existing noise levels: • Larson Davis Model LxT Type 1 Sound Level Meter, Serial # 4085 • Larson Davis Model CAL200 Type 1 Calibrator, Serial # 16455 The sound level meter was field -calibrated immediately prior to the noise measurement and checked afterward to ensure accuracy. All sound level measurements presented in this report, in accordance with the regulations, were conducted using a sound level meter that conforms to the American National Standards Institute specifications for sound level meters (ANSI S1.4). All instruments are maintained with National Institute of Standards and Technology (NISI) traceable calibration, per the manufacturers' standards. Acoustical Analysis Report for 4th and Mortimer • Job # S220404 • July 18, 2022 Page 7 Architecture + Planning 17911 Von Karman Ave. Suite 200 Irvine, CA 92614 ktgy.com 949.851.2133 KTGY Project No: 2017-0934 Project Contact: Debbie Holland Email: dholland@ktgy.com Principal: Wil Wong Project Designer: D. Schoolmeester Project Director: Debbie Holland Developer ED QAK INVES'I'MEN'I'S 4199 CAMPUS DRIVE IRVINE, CA 92612 PHONE NO. (714) 342-2502 TF Z Q 2 H r O N Cn Q U Q Z Q Q Z Q LU w LO T_ LO 06 LO No. Date Description H v , U w 2 U Z Q J It is the clients responsibility prior to or during construction to notify the architect in writing n of any perceived errors or omissions in the plans and specifications of which a contractor thoroughly knowledgeable with the building codes and methods of construction should reasonably be aware. Written instructions addressing such perceived errors or omissions shall be received from the architect prior to the client or clients subcontractors proceeding ' ^ with the work. The client will be responsible for any defects in construction if these procedures are not followed. v, SEp ARCM ILL CV No. C29795 C ) RENEWAL DATE AUGUST 31, 2023 qTF OF � CA\-�F�� License Stamp o EXTERIOR ACOUSTICAL ANALYSIS REPORT COPYRIGHT 7 AO-92