I see there is stated illuminance limits for 'Internally Illuminated Exterior Signage' but there is also an exemption stated for 'internally illuminated signage' and this is causing some confusion. I'm hoping someone can confirm on the interpretation of the exemption for internally illuminated signage.
Does the exemption only apply to an internally illuminated sign that is physically located inside the shell of the building (i.e. located on the inside of a building next to a window)? Or does it also include a sign that is mounted on an exterior wall or hanging on the outside on a window? In either case the signage would be located approximately in the same location for visual puposes, one being outside the glass, one being inside the glass.
Does that glass in this case count as the boundary between being an exemption or not?
Bill Swanson
Sr. Electrical EngineerIntegrated Design Solutions
LEEDuser Expert
731 thumbs up
January 31, 2019 - 11:50 am
Nothing inside of the building applies to this credit.
Any exterior signs that are internally lite need to comply with the luminance limits.
These signs do not need to be counted in uplight and trespass documentation.
Devendra Chaughule
Senior Manager - Sustainable ServicesSurmount
29 thumbs up
October 17, 2019 - 7:44 am
Hi,
Internally Illuminated Exterior Signage - The signage which are illuminated from inside of the signage box where the bulbs/light fittings are kept inside the signage to illuminate. These signage are solely used for exterior communication/marketing purposes as the work exterior is used.
Internally illuminated signage - Same but not exterior signage, may be internal signage kept inside the project premises for internal purpose.
Also, these signs do not need to be counted in uplight and trespass documentation.
Regards
Sara Greenwood
Cadmus Group16 thumbs up
October 13, 2020 - 5:39 pm
Jason, I agree this is confusing. We ran into this on a project also and the guidance for the exemptions listed in the Reference Guide for internally illuminated signage only apply to the uplight and trespass requirements.
Glenn Heinmiller
PrincipalLam Partners
96 thumbs up
October 13, 2020 - 6:44 pm
I think maybe I can help clear this all up for anyone else who stumbles into this thread in the future.
Short answer: Bill in his 31 Jan 2019 post is correct. Devendra, In his 17 Oct 2019 post is (partially) incorrect.
"Internally illuminated signage" is a sign whose light source is inside the sign itself.
The light pollution credit only applies to "exterior luminaires" (fixtures outside the building envelope). Any lighted signage inside the building envelope is irrelevant and does not "exist" as far as the credit is concerned (along with all other interior lighting)
The exemption to the uplight and trespass requirements (not the whole credit) for "internally illuminated signage" is there because internally illuminated signage has its own separate requirement for maximum luminance.
And a note: The lighting of externally illuminated signs (signs that are illuminated by separate light fixtures mounted on the sign, to the building, or elsewhere) is not exempt. The luminaires that light these signs are subject to the same restrictions as any other exterior luminaire. (tip: if mounted on the building you might define them as "facade lighting" and they'd subject to the special exemption for facade and landscape lighting in LZ3)