Proposed by the Laramie Astronomical Society and Space Observers.
All regulations herein apply only to exterior luminaires, not to luminaires whose light is confined inside of buildings.
Any luminaire with a lamp or lamps rated at a total of more than 2,000 lumens (lm) shall be of fully shielded design and shall not emit any direct light above a horizontal plane passing through the lowest part of the luminaire.
Any flood or spotlights under 2000 lm must be directed downward at an angle of 45 degrees or less when visible from any neighboring property.
Luminaires located within 100 feet of any public road in Albany County must be positioned and shielded in such a way as to prevent glare which could impair the vision of drivers using that road.
With the exception of seasonal decorations (see exception below) luminaires which are controlled to repeatedly turn on and off at timed intervals (more than once per hour) are prohibited.
Existing lighting installations will be "grandfathered". However, when an existing outdoor lighting installation is being replaced, or modified, extended, expanded, or added to, the entire outdoor lighting installation on the lot will be subject to regulation.
In the darkest Lighting Zone (E1), there is the further restriction that all exterior lighting, no matter the output, must be low pressure sodium and must be shielded in such a way that direct light from them shall not shine on other properties.
The E1 zones consist of the areas within a three mile radius centered on the University of Wyoming research observatories located at Red Buttes and atop Mount Jelm.
In the residential Lighting Zone (E1R), there is the further restriction that all exterior lighting greater than 2,000 lumens must be shielded in such a way that direct light from them shall not shine on other properties.
The E1R zones consists of all residential areas with a housing density of one unit or more per two acres of land.
All luminaires used to illuminate any parking area, loading bay, maneuvering space or driveway shall be so arranged that all direct rays from such luminaires shall fall entirely within the parking or loading area and shall be shielded to prevent direct light from shining upon abutting properties or streets.
Exception: Seasonal decorations using typical unshielded low-wattage incandescent lamps shall be permitted in all zones from Thanksgiving through January 15.
Exception: Airport, tower, or structure lighting required by federal or state agencies (such as tall communications towers, water towers or tall chimneys where lighting is required to prevent airplane collisions; or lights required for environmental monitoring of smokestack emissions).
Exception: Lighted advertising signs (see advertising section below).
Exception: Wall lighting (see the advertising section below).
Lighted advertising signs and wall lighting:
Lighting for advertising signs and luminaires intended solely to illuminate the walls of any building are not subject to the 2,000 lm limit, but such luminaires shall be aimed and shielded so that the direct light is confined to the surface of such sign or building and the light shall be pointed downward at the sign or wall at an angle of 45 degrees or less, from above, not upward from the ground.
Advertising signs lit from within can meet the light output standards in this regulation by complying with the following design guidelines: Interior-lighted advertising signs should be designed so that the logo and lettering are brighter and of lighter color than the background of the sign. The background of the sign should be opaque or dimly lit and darker in color in relation to the lettering and logo and other relevent parts of the advertising message. The lighted background of the sign should not be white, off-white, cream, yellow or other light colors. The intention is to encourage the approach where the information on the sign (text and logos) is the more brightly illuminated portion, which leads to better legibility and decreased light outputs.
Searchlights or aerial laser displays directed into the sky for purposes of advertising are prohibited.
The use of Low Pressure Sodium lighting is encouraged for general illumination in all zones. Motion sensor activated lights are also encouraged in place of dusk to dawn lights.
Severability.
If any provision of these regulations or the application thereof to any individual or circumstance is invalid, the invalidity shall not affect other provisions or applications of these regulations which can be given effect without the invalid provision or application, and to this end the provisions in these regulations are severable.
Residential refers to all residential land-use zoning, including all densities and types of housing such as single-family detached and duplexes.
Cutoff angle: The angle formed by a line drawn from the direction of the direct light rays at the light source with respect to the vertical, beyond which no direct light is emitted.
Full cutoff light fixture: A luminaire light distribution where no light is emitted above the horizontal, and where the intensity at 80 degrees from nadir is no greater than 100 candela per 1000 lamp lumens.
Luminaire: A complete lighting system, including a lamp or lamps and a fixture.
Fully-shielded luminaire: Constructed in such a manner that all light emitted by the fixture, either directly from the lamp or a diffusing element, or indirectly by reflection or refraction from any part of the luminaire, is projected below the horizontal plane from the lowest part of the luminaire.
Glare: Light emitted from a luminaire with an intensity great enough to produce annoyance, discomfort, or a reduction in a viewer's ability to see.
Height of luminaire: The vertical distance from the finished grade of the ground directly below to the lowest direct light emitting part of the luminaire.
Direct light: Light emitted from a luminaire, off the reflector or reflector diffuser, or through the refractor or diffuser lens.
Indirect light: Direct light that has been reflected off other surfaces not part of the luminaire.
Lamp: The component of a luminaire that produces the actual light.
Fixture: The assembly that houses a lamp or lamps, and which may include a housing, a mounting bracket or pole socket, a lamp holder, a ballast, a reflector or mirror, and/or a refractor, lens, or diffuser lens.
Light trespass: The shining of direct light produced by a luminaire beyond the boundaries of the property on which it is located.
Lumen: A measure of light energy generated by a light source. One foot candle is one lumen per square foot. For purposes of this regulation, the lumen output shall be the initial lumen output of a lamp, as rated by the manufacturer.
The acceptability and shielding restrictions applicable to a particular lamp are decided by its initial lumen output, not wattage; check manufacturer's specifications.
Examples of lamp types of 2000 lumens and less are:
100 Watt Standard Incandescent
15 Watt Cool White Fluorescent
15 Watt Compact Fluorescent
18 Watt Low Pressure Sodium