February 23, 2005
Dear County Council,
County is to be congratulated for recognizing that light pollution is a growing
concern and for addressing it in the Area Plan’s proposed zoning ordinance (http://www.bakerdaniels.com/StJoe/SJC_08_02.pdf). The
beauty of smarter lighter decisions is that everyone wins—the sky becomes
darker, road safety improves, the nightscape is more appealing, and our electric
bill decreases significantly.
Light pollution is an issue that can be easily demonstrated, as an 8-yr. old
recently did for her school project (see http://analyzer.depaul.edu/paperplate/lights.htm).
Most people simply aren’t aware either of the problem or of the
is a large national movement to promote better lighting practices, including
through legislation, and the clearinghouse for many related resources is the
International Dark-Sky Association (IDA) (http://www.darksky.org).
I have studied some of their material, I recognize that much of the technical
language is of the domain of professional lighting engineers.
I also realize your proposed lighting ordinance needs to be detailed
enough to permit enforcement yet simple enough to be interpreted by all
I highly recommend you review the IDA’s “Outdoor
Lighting Code Handbook” (different than the IDA Model Lighting Ordinance) to
get a feel for the light regulation issues.
The whole handbook tutorial is at http://www.darksky.org/handbook/lc-hb-v1-14.html.
You’ll notice their different approach in lighting ordinances is to
zone areas by use, then to put lighting limits per acre on the property (kind of
like spending caps). Nonetheless, the supporting material is great.
Though I am no lighting expert, I feel the St. Joseph County proposed ordinance has some significant shortcomings that must be corrected. In the attached document I summarize some of my concerns and cite links for further information. The IDA is in the process of finalizing its Model Ordinance, so I will borrow from it and criticisms to the IDA’s first draft. Finally, just because the proposed lighting rules have been borrowed from other existing codes does not mean those other codes were necessarily good.
Your recognizing the need for a lighting ordinance is to be commended, as are many of the elements of the proposed lighting ordinance. It is certainly a step in the right direction toward saving the heritage of our night sky.
I appreciate your responsiveness to the community,
Intent: Light trespass
and glare, which are cited in the
proposed regulation, are two of the three major issues related to light
pollution. I request that the
ordinance recognize the third major element—skyglow
from errant uplighting—both in the intent and in the actions of the ordinance.
A1: no comment
A2: This language is a bit confusing to the layman.
I’m not sure if having light posts well in from the property line
wouldn’t encourage lights to be aimed outward toward (and beyond) the outer
The Lighting Standards
section makes some egregious assumptions, and yet this is a cornerstone of the
ordinance. Key intentions of
lighting ordinances are to prevent light
trespass from infringing upon the properties beyond the property owner; to
eliminate the discomfort and danger of glare,
which results from light beamed directly from the luminaire into your eye; and
to limit skyglow from errant upward
lighting (which the St. Joseph proposal does not specifically address,
unfortunately). Let’s start with
the Type of Fixture column.
of the bad lighting you see sometimes on barn sides, where one mercury vapor
light blasts light far and wide. In
that case, the light has no shielding, so you are blinded by the bulb, and light
goes in all directions—including sideways into the sightline of neighbors and
upward into the sky—instead of just down
where it is needed. To limit light
pollution, you simply encase the luminaire fully in a protective covering so the
light direction is controlled. For
elegant simplicity, a “fully shielded” light permits no light above the
horizontal plane of the light fixture. Yet
not all lights on the market are attuned to this consideration.
Momentum has carried product lines for years, even though manufacturers
make plenty of good options (http://www.darksky.org/fixtures/fixtures.html).
require a “fully shielded” light fixture that limits the amount of wayward
lighting does not impose a burden on any consumer, user, architect, or light
designer. Plus, it is
easy to verify whether a light complies with the “fully shielded” definition
simply by looking at it—either it is or it isn’t, as seen from the side. No
need to measure light outputs above certain angles from the nadir, blah, blah,
blah. Compliance is easy to verify (which makes your building
inspector more efficient).
proposed ordinance, however, wades into the murky waters of
less-than-fully-shielded with terms like Cutoff, Full Cutoff, Semi Cutoff, and
Non-Cutoff. While these terms are
defined by the benchmark Illuminating Engineering Society of North America (IESNA)
(www.iesna.org), as a remnant of dated glare
control they are confusing, too technical for the laymen to interpret, too
difficult for an inspector to verify, and too permissive of wayward uplighting. Non-Cutoff,
as illustrated in the proposed ordinance, is the only example that is easy to
understand. Why even distinguish
between a Cutoff and a Semi Cutoff? Why
doesn’t a Cutoff light actually cut off the light below the horizontal line? And if you really want to get into the loopholes, why
doesn’t a Full Cutoff necessary restrict all light below the horizontal as
well? (See http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/lightpollution/cutoffClassifications.asp
and click through a two pages thereafter as well.)
cutoff” and “fully shielded” are not equivalent, as I understand it. I encourage you to limit (or eliminate) the cutoff
designations, and instead concentrate on the fully shielded lighting.
Also, if you insist on using the IESNA terms, there is a disconnect
between the language of the ordinance and the diagrams. As
one commenter wrote to me,
terms full cutoff, cutoff, and semi-cutoff are used without any definition,
expect perhaps in the diagrams below the table. These diagrams appear to show a
unitless ‘definition’ which is NOT the definition of these terms as
defined by the IESNA (www.iesna.org)...Item
#17 specifically requires the plans to show "fixture classification e.g.
cutoff etc...". That implies the IESNA standard definition since that is
what manufacturers are going to use. If you want to use IESNA cutoff
classification as a means of control then get rid of your diagrams, call the
terms ‘IESNA non-cutoff’, ‘IESNA semi-cutoff’, etc. and just
leave it up to the applicant to refer to fixture manufacturers documentation.”
Table 8.08.02 and the Maximum Height column, the notion behind restricting pole
heights is two-fold. First, lower
poles have a more aesthetic appearance along the landscape. From
light control perspective, assuming identical fixtures, lower lights cast less
light outward toward adjoining properties.
There is some debate as to the efficacy of limiting pole heights. If
you have lower poles, you have to install more of them to get ground coverage.
The temptation is for the property owner to make up for the lower pole by
using lights that cast a wider beam. Whereas a high pole can direct the light down onto the
targeted area, a low light that casts outward has a likelihood of spillover and
glare. However, if you aren’t
struggling with the cutoff designations, height becomes less of an issue.
from Table 8.08.02 is the gross shortcoming in the proposed Maximum Wattages
column. The proposed ordinance is
inviting nothing but trouble here. When
we think of wattages, we think of the incandescent light bulbs in our homes.
We can all imagine what a 100 watt light bulb would be like.
But wattage is a measure of electrical consumption, not of light output.
If you must keep table 9.08.02, I encourage you instead to make your
maximum lighting designations in different units, such as lumens.
Different types of lights have different efficiencies, so that
two bulbs of the same wattage may have vastly different amounts of light output.
For example, I believe a person could replace a 100-watt standard
incandescent lamp (1,690 initial lumens) with a 100-watt metal halide lamp,
which puts out five (5) times the amount of light (9,000 initial lumens)! And
in the near future, manufacturers will employ LEDs that give very high light
outputs at a fraction of the wattage, making this bad situation even worse.
I said, the IDA received a many comments regarding similar concerns about its
proposed model ordinance (http://www.darksky.org/ordsregs/mlc/modlicod.html).
If you want to read the cacophony of complaints about specific sections
that very much parallel the St. Joseph proposal, scroll down to the Public
Review section and select your topic. Please
don’t be swayed just by the recommendations of Baker and Daniels.
A6 no comment
A7-A10 First, an organizational item…shouldn’t A7 be one topic (wall pack lights) with A8-A10 being sub-topics (lower case a, b, c)?
A9 Recommend you replace full cutoff with “fully shielded”
A10 (Again you have the recurring terminology problem and the wattage-versus-lumen problem from above.) If you permit Non Cutoff, you open the door for uplighting (the one cause of light pollution not tackled in the proposed ordinance). People are going to uplight the facades of buildings in the name of architectural highlighting as pseudo advertisement to bypass restrictions on signage. If you insist on allowing wall packs for architectural highlighting, at lease require the lights not to cause glare, light trespass, or sky glow. Wall packs that point up are nothing but bad news.
A11 (Again you have the recurring terminology problem and the wattage-versus-lumen problem from above.)
A12 no comment
A13 The proposed ordinance addresses glare, thankfully, but again falls far short in curbing light trespass and sky glow. As worded, this doesn’t discourage reckless lighting of flags, statues, and architectural elements. Direct uplighting should be addressed specifically in the proposed ordinance to minimize its impact.
A14 Floodlights have a wider beam than spotlights, so the spillover beyond the floodlight’s main beam is enormous. Perhaps consider requiring that floodlights be raised no more than 45 degrees from straight down. Here again the proposed ordinance does not address sky glow.
A15 no comment
A16 no comment
A17 (Again you have the recurring terminology problem and the wattage-versus-lumen problem from above.)
B1 no comment
B2 no comment
C1 no comment
C2 I object to the exemption of public lights from this ordinance. Why should we allow St. Joseph County to be cavalier with its lighting? A major benefit of having the county comply with this ordinance is the forced savings for taxpayers. I don’t want the county putting in light fixtures that waste 50% to the sky. What kind of money management is that? The IDA expresses my other sentiment:
“Some municipalities exempt themselves from compliance with lighting codes. It is hard to avoid the impression that the municipality holds itself above the rest of the community when such things are done, and also such a practice sends entirely the wrong message that good lighting is not for everyone. Such exemptions are to be strongly discouraged. In fact, communities should strongly consider programs to bring all publicly owned lighting into conformance with the lighting code, as a leading example for the entire community and an example of the benefits quality lighting can bring.”
C3-C6 no comment
D1 –D2 no comment
E1 no comment
E2 I’m not sure I understand this sentence about floodlights, as written, particularly how it pertains to floodlights that are “used to illuminate the site, buildings, and structures.” How are floodlights prohibited?
E3 no comment
As the St. Joseph County Council prepares to enact a new lighting ordinance, you may send your input to the appropriate individuals whose contact information is listed at county.htm. More current information on light pollution issues is www.nightwise.org.
Copyright ©2003-2008 Chuck Bueter. All rights reserved.