Outdoor Lighting Ordinance Questions

Frequently asked questions about the Outdoor Lighting Ordinance.

Who must follow this Outdoor Lighting Ordinance?

All private property owners and municipal buildings must follow this ordinance.
What are the two types of standards that a property owner can follow?

Any property owner can choose to follow a Prescriptive Standard or a Performance Standard but they have to choose which one to utilize.

The Prescriptive Standard is the lighting practice most property owners will follow since it outlines specific types of light fixtures and lumen limits on various site conditions around the property. This standard is easy to follow by property owners and review by the Inspectional Services Department (ISD).

The Performance Standard is a more technical process that requires a lighting professional to create a lighting plan. It will be followed by property owners that want to create a complicated design that implement the U.S. Green Building Council’s LEED Light Pollution Reduction Credit or a lighting boundary at the property line with a maximum vertical illuminance of 8.0 Lux as defined by the Model Lighting Ordinance (MLO) created by the Illuminating Engineering Society (IES) and the International Dark-Sky Association (IDA).
Are there different standards for commercial and residential properties?

No, any property owner can choose to follow the Prescriptive Standard or the Performance Standard.
What type of fixtures and light bulbs are allowed under the ordinance?

It depends on the site conditions. Any property owner can choose to comply with the following Prescriptive Standard. The lighting levels listed under each site conditions are maximum limits and property owners can choose to use lower levels.

Facing the Street – A light fixture can be fully, partially or not shielded and can be mounted up to 12’ above the surface to be illuminated. Example of this site condition is a front yard. The maximum lumen limit for new and replacement light fixtures and light bulbs is 630 lumens.

Lighting Entrances, Walkways & Open Spaces - A light fixture must be fully shielded and can be mounted up to 12’ above the surface to be illuminated. Examples of this site condition are light fixtures next to doorways, paths, outdoor stairs or open spaces that need a focused, brighter light. The maximum lumen limit for new and replacement light fixtures and light bulbs is 1,050 lumens.

General Locations anywhere along the Property – A light fixture in this general condition can be fully, partially or not shielded and can be mounted up to 12’ above the surface to be illuminated. Examples of this site condition are lights placed around the property for safety and security or general use. The maximum lumen limit for new and replacement light fixtures and light bulbs is 315 lumens.

Parking Areas & Driveways – A light fixture must be fully shielded and can be mounted up to 14’ above the surface to be illuminated. Examples of this site condition are driveways, garages, parking spaces, parking lots, and loading bays that need a focused, brighter light. The maximum lumen limit for new and replacement light fixtures and light bulbs is 1,260 lumens.

This illustration, courtesy of Bob Crelin and the New England Light Pollution Advisory Group, shows examples of unshielded or partially shielded light fixtures, which are restricted in certain conditions listed above, and fully shielded light fixtures, which are allowed under all site conditions.
Besides lumens and light fixture designs, do we need to look at other light specifications?

Yes, the correlated color temperature of any outdoor light bulb cannot exceed 3500 Kelvin. This, along with lumen information, can be found on the Lighting Facts Label that is on all light bulb packages to determine if it meets the City standards.

Pay attention to Brightness (lumens) and Light Appearance (color temperature) for each bulb. We list the maximum limits under the Prescriptive Standard but encourage property owners to use the lowest lumen and color temperature needed. This will help reduce light pollution, light trespass and promote energy conservation.
Is there a limit on the number of light fixtures under the Prescriptive Standard?

No, there is not a limit on the number of fixtures but property owners are encouraged to install the minimum number of fixtures necessary for the safe use and enjoyment of outdoor areas.
When do I have to comply with the new Outdoor Lighting Ordinance?

All property owners have 5 years from the ordinance effective date to bring their existing light fixtures into compliance with the new standards. All replacement and new light fixtures or light bulbs must comply with the new standards immediately.
What if I am impacted by a problematic light fixture now?

Any resident or property owner can file a complaint about problematic light fixtures with Inspectional Services Department (ISD). Inspectors will review their records to determine if the proper permit was acquired to install the fixture. If it was properly installed under the existing standard then the property owner will have 5 years to comply with the new standard. If the property owner replaces the light fixture or light bulbs then they must comply with the new standard immediately.

If it can be determined that the fixture was improperly installed then the property owner must replace the fixture following the new standard immediately.
What information must I provide when installing a light fixture?

Similar to the current requirement, only a licensed electrician can install a light fixture that is hardwired to an electrical system. This does not change with the new lighting standard.

If the property owner follows the Prescriptive Standard, then the licensed electrician will sign an affidavit on the Electrical Permit Application that the new or replacement light fixture(s) comply with the new Outdoor Lighting Ordinance.If the property owner follows the Performance Standard, then a construction control affidavit must be completed by a licensed architect or professional engineer and include a lighting plan as defined by the ordinance.
What circumstances are exempt from complying with the ordinance?
- Lighting within public ways for the principal purpose of illuminating public ways.
- Lighting for public parks or public art that is commissioned, owned, or operated by a city, state, or federal entity, or that is required by the City, by special permit, or otherwise by law to be accessible to the general public.
- Lighting for public monuments, statuary, or the national flag.
- Architectural lighting that has received a Certificate of Appropriateness from the Cambridge Historical Commission or Neighborhood Conservation District.
- Architectural lighting of structures or buildings listed on the National Register of Historical Places.
- Lighting solely for signs as regulated under Article 7 of the Cambridge Zoning Ordinance.
- Temporary lighting for theatrical or television production, or performance areas, if an electrical permit has been received from the City’s Inspectional Services Department.
- Temporary lighting for work areas at construction sites, if an electrical permit has been received from the City’s Inspectional Services Department.
- Underwater lighting in swimming pools and other water features.
- Temporary lighting or seasonal lighting as defined in this Ordinance.
- Lighting for hospital emergency departments, including associated helipads.
- Lighting that is only used under emergency conditions.
- Lighting required by federal, state, or local laws, rules or regulations.
What if there are special circumstances that require lighting that does not comply with the ordinance?

The property owner can apply to the Commissioner of ISD for an Administrative Exemption if it can be demonstrated that compliance with the new outdoor lighting ordinance is an unreasonable hardship or detrimental to public health, safety or welfare.

The Commissioner of ISD has the authority to create a provisional exemption and outline the necessary conditions and reasonable steps that the applicant must take to bring the lighting into compliance.
Who can complain about nuisance outdoor light fixtures?

Anyone can complain to ISD about inappropriate outdoor light fixtures.
How will the City enforce the Outdoor Lighting Ordinance?

After a complaint is filed with ISD an Inspector will determine if the light fixture complies with the Outdoor Lighting Ordinance and what appropriate action, if any, must be taken by the property owner. If the property owner does not comply with the ISD instructions then a citation with a $300 fine can be issued for each violation.
Where do I get more information about the new Outdoor Lighting Ordinance?

For more information, please contact:

Inspectional Services Department

831 Massachusetts Avenue, Cambridge, MA 02139

Phone: 617-349-6100

Website: www.cambridgema.gov/inspection