appendix iv.b lighting study - la city planning · pdf file1 april 2015 brentwood school...

APPENDIX IV.B Lighting Study

1 April 2015

Brentwood School Education Master Plan Lighting Evaluation

By: Lighting Design Alliance 1 April 2015

1 April 2015

Brentwood School Education Master Plan LD‐1 Lighting EIR

Brentwood School Education Master Plan Lighting and Glare Analysis Contents: 1.0 Executive Summary 2.0 Project Introduction 2.1 Existing Conditions 2.2 The Project 2.3 Intended Operations 2.4 Proposed Lighting Design 2.5 Project Design Features 3.0 Regulatory Framework 4.0 Potential Impacts 5.0 Mitigation Recommendations 6.0 Conclusion Appendix A

Existing Site Photos Appendix B Field Calculations Light Spread Lighting Calculation Fixture Cutsheet Appendix C

Chip Israel Resume

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1.0 EXECUTIVE SUMMARY This report considers the potential lighting impacts of the proposed Brentwood School Education Master Plan. The Brentwood School Education Master Plan is a 30‐year plan for enhanced facilities on both the East and the West Campuses. Current sources of illumination within both Campuses are associated with outdoor security lighting and office and classroom windows. There are outdoor pole‐mounted light fixtures and lighting fixed to the outside of buildings with hooded down‐facing lights. The lights are located along walkway paths and within parking lots. Most of the lighting is interior to each of the Campuses; thus it is blocked from view from outside the Campuses by the on‐site buildings and perimeter vegetation and landscaping. Currently the athletic fields are not lighted. While various angles of view from outside the Campuses may allow for glimpses of on‐site lighting, light spillage from within the Campuses onto adjacent uses is generally limited. As part of the Brentwood School Education Master Plan, the School proposes to install lighting for the existing athletic (Football) field that is located on property leased from the Veterans Administration that provides facilities for the East Campus. The balance of this report will focus on lighting analysis for the addition of lighting fixtures for the East Campus only since all other lighting impacts will be similar to the existing conditions.

This report examines the potential impact of athletic field lighting as it pertains to the surrounding neighborhood, and most importantly adjacent residences. This review is limited to the addition of four, seventy foot poles with 44 fixture heads. All of the heads are mounted so that they are aimed towards the football field, with no fixtures aimed outward to pedestrian or parking areas. The Football field is located down into a natural arroyo which naturally assists in containing the light. The athletic field surface is located at 431 feet with the top of the adjacent berms or bluffs with an elevation of approximately 480 feet. With the use of 70 foot tall poles, the net height of the poles would be 21 feet above the top of the adjacent berms or bluffs. Design Solution: Sports field illumination is designed to provide functional and aesthetic illumination of both the field surface, as well as the air directly above the playing surface. This allows the athletes to see the other athletes, but also the balls when thrown or kicked into the air. High performance light fixtures are required to ensure that all of the light is focused into this action zone, without creating glare to the athletes, spectators or adjacent properties. Tall poles are required so that the light can be aimed down towards the action zone, verses horizontally or upwards. This minimizes glare to the athletes, observers and adjacent properties and helps contain the light to where it is needed. While many companies make athletic field light fixtures or luminaires, Musco was selected for their precise optics and extended glare louvers. The fixtures are designed to light the action zone and eliminate off site light trespass or light pollution, also known as sky‐glow. Four poles with a height of 70 feet were selected. Each pole includes a total of 12 fixtures and the light fixtures use a 1,500 watt metal halide solution.

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Lighting evaluation: The City of Los Angeles Municipal Code requires that all spill light or light trespass be limited to 2 footcandles at the adjacent neighboring residential property. The physical geography of the terrain, the existing landscaping and the adjacent existing developments will physically block any potential stray light from ever reaching the majority of the adjacent residential neighbors. The athletic field sits in an arroyo, nearly 431 feet below most of the adjacent area. This will naturally act as a physical barrier, plus it lowers the net height of the poles by the same amount, reducing the possibility of seeing any lighting hardware. The adjacent barriers on the bluffs at approximately 480 feet also act as a shield or barrier to residential areas. To the West there are campus buildings; and to the South there are commercial retail developments. On the North edge of the berm, there is a tall, thick grove of trees, physically located between the field and the residences. The calculations provided by the manufacturer showed a field illumination of between 37.6 footcandles and 61.7 footcandles, with an average of 51.1 footcandles. Lighting Design Alliance also provided independent calculations using IES photometric files provided directly by the manufacturer. Using AGI illumination software, new calculations were provided to verify the manufacturer’s calculations. This same software was used to calculate how much light would extend into the neighboring open space and private residential properties. The calculations indicate less than .02 footcandles at a distance of 100 feet from around the football field. At 200 feet, the lighting calculations all drop to 0.0 footcandles or no attributable light. Therefore, any open space or structure outside of the 200 zone would be well below the City of Los Angeles Municipal Code requirement which allows no more than 2 footcandles of spillover light on to private property developed with a residential use. The calculations, as well as the physical constraints, ensure that there will be no significate impacts to the adjacent residential areas from the proposed football field illumination.

2.0 PROJECT

2.1 Existing Conditions The Brentwood School Education Master Plan is a 30‐year plan for enhanced facilities on both the East and the West Campuses. Current sources of illumination within both Campuses are associated with outdoor security lighting and office and classroom windows. There are outdoor pole‐mounted light fixtures and lighting fixed to the outside of buildings with hooded down‐facing lights. The lights are located along walkway paths and within parking lots. Most of the lighting is interior to each of the Campuses; thus it is blocked from view from outside the Campuses by the on‐site building and perimeter vegetation and landscaping. Currently, the athletic fields are not

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lighted. While various angles of view from outside the Campuses may allow for glimpses of on‐site lighting, light spillage from within the Campuses onto adjacent uses is generally limited. As part of the Brentwood School Education Master Plan, the School proposes to install lighting for the existing athletic field that is located on property leased from the Veterans Administration that provides facilities for the East Campus. The balance of this report will focus on lighting analysis for the addition of lighting fixtures for the East Campus only since all other lighting impacts will be similar to the existing conditions. The East Campus is approximately 7.5 acres in size and is predominantly located within an arroyo that contains variations in topography, including relatively flat bottom areas with steep slopes on each side that ascend toward Layton Drive and the residential area on the northeast and Barrington Place and Brentwood Village on the southwest. Most of the buildings and athletic fields and facilities are on relatively flat stepped terraces built into the floor of the arroyo and the slope on the Layton Drive side of the Campus. The Project Site is within the urbanized community of Brentwood, which includes residential and commercial uses, schools, parks, churches, synagogues, and institutional uses. Lighting from uses surrounding both Campuses contributes to the high ambient nighttime light levels that characterize the area. The closest sources of existing illumination off site include street lighting along the Sunset Boulevard corridor; security, signage, and parking lot lighting in the Brentwood Village commercial area located next to the East Campus; residential lighting in the residential areas north and south of each Campus; and lighting in parking lots of other educational and religious institutions between the two Campuses and adjacent to the West Campus. Headlights from passing vehicles on Sunset Boulevard and local roadways also contribute to the lighted character in the immediate vicinity. In addition, the urbanized environment and proximity to Interstate 405 create an overall nighttime glow that eliminates any dark sky qualities in the area.

2.2 The Project

Athletic Field An existing athletic field is located on property leased from the VA and is located toward the southern part of the East Campus on the floor of the arroyo and is approximately 431 feet below adjacent structures. Design Solution The athletic field is a full‐size football field. The main field is 120 yards (360 feet) long by 53.3 yards (160 feet) wide. The adjacent space for sidelines and spectator areas expands this area to an approximate size of 150 yards (450 feet) by 100 yards (300 feet). Sports field illumination is designed to provide functional and aesthetic illumination of both the field surface, as well as the air directly above the playing surface. This allows the athletes to see the other athletes, but also the balls when thrown or kicked into the air. Additional information in regards to Athletic field illumination can be provided in the IES’ “Sports and Recreational Area Lighting/RP‐6‐01/2009” guideline.

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High performance light fixtures are required to ensure that all of the light is focused into this action zone, without creating glare to the athletes, spectators or adjacent properties. Tall poles are required so that the light can be aimed down towards the action zone, verses horizontally or upwards. This minimizes glare to the athletes, observers and adjacent properties and helps contain the light to where it is needed. While many companies make athletic field light fixtures or luminaires, Musco was selected for their precise optics and extended glare louvers. The fixtures are designed to light the action zone and eliminate off site light trespass or light pollution, also known as sky‐glow. Four poles with a height of 70 feet were selected. Each pole includes a total of 12 fixtures and the light fixtures use a 1,500 watt metal halide solution. All fixtures are intended to aim downwards, directly to the playing field.

2.3 Intended Operations Athletic Field The athletic field is not intended to be used on weekdays past 10:00 pm and would be used only during limited daytime hours on weekends (no lights on weekends). The athletic field is intended to be used for recreational play only, placing it in a “Class of Play” of IV according to the Illuminating Engineering Society (IES).1

Proposed Lighting Design

Athletic Field Sports field illumination is designed to provide functional and aesthetic illumination of both the field surface, as well as the air directly above the playing surface. This allows the athletes to see the other athletes, but also the balls when thrown or kicked into the air. High performance light fixtures are required to ensure that all of the light is focused into this action zone, without creating glare to the athletes, spectators or adjacent properties. Tall poles are required so that the light can be aimed down towards the action zone, verses horizontally or upwards. This minimizes glare to the athletes, observers and adjacent properties and helps contain the light to where it is needed. While many companies make athletic field light fixtures or luminaires, Musco was selected for their precise optics and extended glare louvers. The fixtures are designed to light the action zone and eliminate off site light trespass or light pollution, also known as sky‐glow. Four poles with a height of 70 feet were selected. Each pole includes a total of 12 fixtures and the light fixtures use a 1,500 watt metal halide solution. The calculations provided by the manufacture showed a field illumination with an average of 50 footcandles. Lighting Design Alliance also provided independent calculations using IES photometric files provided directly by the manufacturer. Using AGI illumination software, new calculations were provided to verify the manufacturer’s calculations and to verify the amount of light, outside of the playing field boundaries.

1 Illuminating Engineering Society: The Lighting Handbook Tenth Edition, Section 35.1: Project Type and Status, Table 35.2

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Each fixture would be individually aimed towards the field and use one of Musco’s visor systems (see Figure 2.3‐1) which allows for better light control, reduced glare, and reduced spill light. The fixtures also include an integral house side shield to minimize any spillover light behind the fixtures. The combination of the glare shield and the house side reflector eliminates any lighting past a 200 foot boundary around the football field.

Figure 2.3‐1 Musco luminaire with visor system

2.4 Project Design Features

The following Project Design Features are relevant to the athletic field lighting and have been taken into account in this analysis. PDF LT‐1: Outdoor lighting for the East Campus Upper School Athletic Field shall include a control and monitoring system for flexible control and management of lighting to allow athletic events to occur into the post‐dusk evening hours. The lights shall be hooded and directed downward to the field such that they shall not create more than 0.5 footcandle of spillover light at ground level at the property line of any adjacent off‐site residential uses not owned by Brentwood School. There are no residential uses on the Project Site. PDF LT‐2: All exterior night lighting installed on the East and West Campuses shall be of low intensity, low‐glare design and hooded to direct light directly downward onto the area being lighted to prevent spillover onto adjacent parcels. Exterior lighting fixtures must be kept to the minimum number and intensity needed to ensure public safety. These lights shall be dimmed after 10:00 PM to the maximum extent practical without compromising safety. Upward directed exterior lighting is prohibited. All exterior lighting fixtures must be appropriate for the architectural style of the campuses. PDF LT‐3: The use of field lighting for all outdoor athletic facilities shall be limited to only those hours during which the facilities are being utilized, and shall not be used past 10:00 PM, with exceptions for football games that require overtime due to a tie score.

3.0 REGULATORY FRAMEWORK

A number of Los Angeles Municipal Code (LAMC) chapters relate to the regulation of lighting, as summarized in the following:

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• Chapter 1, Article 2, Section 12.21 A 5(k): All lights used to illuminate a parking area shall be designed, located, and arranged to reflect the light away from any streets and adjacent premises. • Chapter 1, Article 7, Section 17.08: Plans for street lighting shall be submitted to and approved by the Bureau of Street Lighting for subdivision maps. • Chapter 9, Article 3, Section 93.0117: No exterior light source may cause more than 2 foot‐candles of lighting intensity or generate direct glare onto exterior glazed windows or glass doors; onto elevated habitable porches, decks, or balconies; or onto any ground surface intended for uses such as recreation, barbecue, or lawn areas or any other properties containing a residential unit or units. • Chapter 1, Article 4.4, Section 14.4.4. No sign shall be arranged and illuminated in a manner that will produce a light intensity of greater than 3 foot‐candles above ambient lighting, as measured at the property line of the nearest residentially zoned property.

4.0 POTENTIAL IMPACTS

As defined by the LA CEQA Threshold Guide, the significance threshold shall be made on a case‐by‐case basis, considering the following factors:

The change in ambient illumination levels as a result of project sources; and

The extent to which project lighting would spill off the project site and affect adjacent light‐sensitive areas.

Light trespass or light pollution can introduce glare or stray light into private, residential lots. The balance of ambient light to promote pedestrian safety and a sense of security must be compared to stray light that could affect a resident from sleeping at night in their own bedroom. Section 93.0117 of the City of Los Angeles Municipal Code (LAMC) provides that no person shall construct, establish, create, or maintain any stationary exterior light source that may cause the following locations to either be illuminated by more than two footcandles of lighting intensity or receive direct glare from the light source:

1. Any exterior glazed window or sliding glass door on any other property containing a residential unit or units

2. Any elevated habitable porch, deck, or balcony on any other property containing a residential unit or units

3. Any ground surface intended for uses such as recreation, barbecue, or lawn areas on any other property containing a residential unit or units.

It has been previously noted that the landscape and natural topography surrounding the proposed site, as well as the existing buildings, will visually block the light from the athletic field lighting

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5.0 Mitigation Recommendations Based on the proposed design, we recommend the following steps be considered to ensure minimal lighting impact on adjacent private residences:

1. The following ensures that this Project shall comply with section 93.0117 of LAMC. Spillover lighting levels shall not exceed 2.0 fcs on adjacent privately owned residential properties.

2. Musco sports lighting fixtures (or equal alternative) with visor system shall be used to illuminate the athletic field to provide better light control, reduce glare, and reduce the amount of spill light.

3. Sports lighting fixtures shall be on a time clock to ensure the fixtures are dimmed at or before 10:00 pm on weeknights, unless a game goes into overtime.

6.0 CONCLUSION

Based on calculations provided by Lighting Design Alliance and reviewing calculations provided by the manufacturer, Musco, it has been determined that no spillover light from the Athletic field illumination would impact any neighboring open spaces or private residences. All proposed lighting fixtures would be shielded to prevent any potential glare to the residences, motorists and adjacent commercial structures. Any potential glare caused by the reflection from direct sunlight on the athletic field would be mitigated by the diffuse material of the Field Turf. After a complete analysis and review of the Project, the proposed lighting design for the athletic field, will not result in any significant impacts to the adjacent private residences and no mitigation is required.

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Aerial maps showing adjacent residential areas

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APPENDIX A

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APPENDIX B Lighting Design Alliance also provided independent calculations using IES photometric files provided Directly by the manufacturer. Using AGI illumination software, new calculations were provided to verify the Manufacturer’s calculations. The calculations confirm no measurable light (0.00 Footcandles) outside of 200 feet from playing area.

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This same software was used to calculate how much light would extend into the neighboring open space and private residential properties. The calculations indicate less than .02 footcandles at a distance of 100ft. from around the football field. Shown below

1 April 2015


appendix iv.b lighting study - la city planning · pdf file1 april 2015 brentwood school...

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