Internally Illuminated Signage

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.

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

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.

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)  

As Glenn predicted, I stumbled on this thread.  I thought to politely add that I'm reading the Exemptions to also require "provided it is controlled separately from the nonexempt lighting".  In the case of IIES, this control requirement would seem to align with and allow a project to achieve its "daytime" and "nigthtime" luminance requirements.

Yes, all exempt items must be seperatley controlled to be exempt, including Internally Illuminated Exterior Signage. But this control requiremnt doesn't have anything to do with the day/night luminance limits.I believe the "must be seperatley controlled" is there to just make sure that the exempt lighting could be turned off early and not left on all night, or turned on and off only as needed (e.g. helipads)