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Credit language straight from USGBC
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23 Comments
Using option (3) measuring lighting (%) percent
Using Option (3) it states under the LEED - EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. V3 2009 a minimum of 8 measurements at 100 feet spacing between mesuements must be peformed.
Question? We are a large Convention Center and would like to know how many measurements are actually required. Do we do one measurement every 100 feet until the entire perimeter has been completed. Or can we do a (Percent) measurement at certain locations which would be a representation of the total measurements? Please Advise....Thank You Rey
Dan Ackerstein replied Principal, Ackerstein Sustainability, LLC Feb 22 2010
One measurement every 100 feet until the entire perimeter has been completed is the correct approach. Gaps of larger than 100 feet would allow for too large undocumented spaces, or at least that is the concern.
Exterior illumination measurement methodology
When peforming the exterior illumination measurements, do both horizontal and vertical foot-candle measurements need to be taken? Or just one or the other?
Dan Ackerstein replied Principal, Ackerstein Sustainability, LLC Feb 22 2010
One or the other should be sufficient Kevin; in most instances my suspicion is that horizontal foot-candles are the right measurement, but I don't think either method is specifically required by the credit language, nor is it required that you perform both methods of measurement at each measurement point.
Dan Prows replied Feb 22 2010
Sorry for chiming in, but I have a question that is along these lines...should the 100' measurement protocol be used as the standard for measuring light transmittal in an NC (warehouse) project where shading the windows are not an option, but the lighting is so high compared to the clerestory windowsPronounced and sometimes spelled "clear-story," these are vertical, or close-to-vertical, windows high in the wall of a building that bring daylight deeply into the building and, if operable, can help ventilate the space. that very little light will be emitted? Any ideas on how to measure the true affect? LEED does not specify in BD&C.
Dan Prows replied Feb 22 2010
Sorry for chiming in, but I have a question that is along these lines...should the 100' measurement protocol be used as the standard for measuring light transmittal in an NC (warehouse) project where shading the windows are not an option, but the lighting is so high compared to the clerestory windowsPronounced and sometimes spelled "clear-story," these are vertical, or close-to-vertical, windows high in the wall of a building that bring daylight deeply into the building and, if operable, can help ventilate the space. that very little light will be emitted? Any ideas on how to measure the true affect? LEED does not specify in BD&C.
Option 2: 50 Watt fixture or 50 Watt lamp?
Does the option 2 exemption for exterior lighting apply to fixtures with ratings greater than 50 watts but using lamps 50 watts or less? We have a project with unshielded exterior light fixtures, and our first thought was to make sure each lamp is 50 watts or less as an easy way to satisfy the exterior lighting demands of this credit.
Dan Ackerstein replied Principal, Ackerstein Sustainability, LLC Feb 26 2010
I think your interpretation is consistent with the credit intent - the objective is to reduce illumination to the night sky, and reducing wattage certainly does so. Depending how much you reduce wattages, it may be more or less ultimately effective than shieldingShielding is a nontechnical term that describes devices or techniques that are used as part of a luminaire or lamp to limit glare, light trespass, or sky glow., but it does meet the requirements.
Option 3 - Light Measurments vs Zone Requirements
When finding the difference between light measurements when fixtures are on and off, if the difference is above 20% but the footcandle measurement is below the Maximum Illumination Value for the type of lighting zone does it still comply? For example, if we were in LZ 4 where the maximum is .6 and we got a measurement of .3 with lights off and .4 with lights on (33% difference). Would it be acceptable if one of the requirements is met or does the compliance path have to follow one of the options?
Bill Swanson replied PE, LEED AP, BETA Design Apr 19 2010
It sounds like it does not comply. The credit states "The illumination
level measured with the lights on must not be more than 20% above the level measured with the lights off."
A couple ideas come to mind. Can you shift the measuring points? It states that you need at least 6 points and no more than 100' apart along the perimeter. Sometimes a 20-50' shift can show surprisingly different results.
If that doesn't work you have a small chance getting this by increasing your accuracy. Does you light meter measure hundredths? If the 0.3 fc1. A footcandle (fc) is a measure of light falling on a given surface. One footcandle is defined as the quantity of light falling on a 1-square-foot area from a 1 candela light source at a distance of 1 foot (which equals 1 lumen per square foot). Footcandles can be measured both horizontally and vertically by a footcandle meter or light meter. 2. The non-metric measurement of lumens per square foot, one footcandle is the amount of light that is received one foot from a light source called a candela, which is based on the light output of a standardized candle. A common range for interior lighting is 10 to 100 footcandles, while exterior daytime levels can range from 100 to over 10,000 footcandles. Footcandles decrease with distance from the light source. The metric equivalent of a foot candle is 10.76 lux, or lumens per square meter. value is 0.33 fc with lights off and the 0.4 fc is 0.39 fc with lights on it would be compliant. It's not likely but if you're looking for any ideas it's something to try.
Limited Exterior Lighting Fixtures
Our project is an office space within a warehouse. The only exterior light fixture attached to our property is at the back entrance of our parking garage. Can we still achieve this credit if the scope is so limited? we will be replacing the exterior fixture for one with full cut-off, however, the rest of exterior lights are owned by others.
Tristan Roberts replied Editor – LEEDuser, BuildingGreen, LLC Jun 11 2010
The main thing I want to respond to is about your whole project, not SSc8. Are you planning to certify just the office space within the warehouse? According to the LEED Minimum Program Requirements for EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems., "LEED projects must include at least one existing commercial, institutional, or high-rise
residential building in its entirety."
In principle, I don't know of an obstacle to achieving this credit if it just involves one exterior light fixture. Make sure to address the interior requirements as well.
City-owned streetlights within site boundary
Our project has exterior lighting that is fully shieldedIn a fully shielded exterior light fixture, the lower edge of the shield is at or below the lowest edge of the lamp, such that all light shines down., however a few streetlamps on the project boundary emit ample light to the night sky. These lamps are on the sidewalk, but technically within our site area. Since they are out of our control, is there any way to reconcile with this credit?
Dan Ackerstein replied Principal, Ackerstein Sustainability, LLC Jun 20 2010
Well, the specifics here can be fairly important. If the lights are 'on' the boundary and owned by the city, they clearly fall outside of your sphere of responsibility. If they are, in fact, within your project boundary, I can imagine two options: the first would be to make the 'control' argument to the GBCI, which I think would be a fairly compelling argument. There's really nothing you can do about city-owned fixtures. Alternately, and perhaps more reliably, you could use the Option 3 approach (with the city-owned lights 'on' in both scenarios) to illustrate that the contribution of the lights you DO control to the nighttime lighting situation is marginal.
Interior Light Fixture exemption - no direct line of site
Our building is a warehouse with only a single string of clerestory windowsPronounced and sometimes spelled "clear-story," these are vertical, or close-to-vertical, windows high in the wall of a building that bring daylight deeply into the building and, if operable, can help ventilate the space. at the peak of a gabled roof. All interior light fixtures are ceiling hung T-8s that are 10-12 feet below the bottom edge of the clerestory. I cannot determine how to execute this calculation, as the fixtures obviously have no direct line of site from the building. By changing the orientation of some of the calculations, this would work there were skylights, but in fact it a vertical clerestory window in the roof, not in the walls of the building. Could we show photos of the interior and sections of the building with as an alternative compliance method for Interior Lighting? Anyone have experience with this type of alternative compliance method?
Bill Swanson replied PE, LEED AP, BETA Design Jul 06 2010
For interior lights this credit is looking for a direct line of site to an opening in the building envelope, either wall or ceiling.
What type of ceiling hung T-8 fixtures are these? What does the photometric curve look like? I'm guessing that there's at least some up-light from these lights. If you were at the windows would you be able to see direct light from the T-8 fixtures?
I think a section of the building with light fixture location shown is good for showing compliance. Also attach a copy of the light fixture cutsheet showing what type of fixture this is. Usually the last page of the cutsheet shows the photometric output. If it shows no light coming out of the top of the fixture (between 90 and 180 degrees) then you're good.
If there is direct light going out the windows then automatic controls will need to be shown stating the lights are off 50% of the night hours. At least for the lights within site of the windows.
If this doesn't answer your question let me know.
light pollution reduction for ' interiors of a resort building'
My project is a resort building where the public areas (lobby ,corridors etc )have automatic control panels to switch off lights after 11 pm.However,the remaining portion i.e. the guest rooms have lighting fixtures that might not be able to comply with the distance or angle exemption rules.
The guest rooms have a key card occupancy control as when there are no guests the room has no power supply.Can the guests rooms be counted under automated control areas?The survey shows that 90% of the guests switch off their lights before 12 PM.
Bill Swanson replied PE, LEED AP, BETA Design Aug 04 2010
CIRCredit Interpretation Ruling. Used by design team members experiencing difficulties in the application of a LEED prerequisite or credit to a project. Typically, difficulties arise when specific issues are not directly addressed by LEED information/guide from NCv2.2
9/25/2008 - Ruling
[3] Residential spaces may not be exempted from the interior lighting requirements. ... However, as an alternative for residential spaces, demonstrate that less than 10% of the total lumens emitted by each luminaire are not directly emitted out of the building through any fenestration.
ZEB Tech singapore replied ESD Consultancy, ZEB-Technology Pte Ltd Aug 13 2010
Thank you Bill.Another doubt that I have is that my project building is 16 years old.We do not have any lighting plans for the common areas but all are 100% automatic control with fixed lighting schedule.For my submission is it mandatory to provide the lighting layout for areas which fall under automatic lighting control or would it be enough to mention or mark out the zones on a space layout plan?
Bill Swanson replied PE, LEED AP, BETA Design Aug 16 2010
I have never submitted for a LEED-EBOMEBOM is an acronym for Existing Buildings: Operations & Maintenance, one of the LEED 2009 rating sytems. project so I'm not sure but just from reading the credit it seems you do not need a plan showing interior lighting. Just comment that all interior lights have automatic controls and the total programmed hours of after-hours time is 2,190 hours or less for the year.
ZEB Tech singapore replied ESD Consultancy, ZEB-Technology Pte Ltd Aug 16 2010
Thank You.
Performance Period
So would the minimum performance period for this credit be 1 week or is it 90 days?
Dan Ackerstein replied Principal, Ackerstein Sustainability, LLC Aug 30 2010
For credits like light pollution reduction, which are largely about the equipment choices made for a building (shielded fixtures) or equipment setpointsSetpoints are normal operating ranges for building systems and indoor environmental quality. When the building systems are outside of their normal operating range, action is taken by the building operator or automation system. (programming time clocks to turn off lights at night), the expectation is that the equipment and program are in place for the entirety of the three-month performance period.
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