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Zoning, planning & development

Get a sky plane review

Service overview

Building projects located on CMX-4 and CMX-5 lots have bulk and mass requirements. These rules safeguard the balance between open space and development in Center City.

Sky plane controls are one option for complying with the requirements. By limiting how much visible sky a building can block, this method protects light and viewsheds within dense street corridors. The sky plane requirements vary by street.

You can show your project’s compliance by undergoing a sky plane review. Alternatively, you can demonstrate compliance with bulk and height requirements by using open area controls, which limit the lot coverage of a building at various height intervals.

When you apply for a zoning permit, the Department of Licenses and Inspections (L&I) will identify projects that may choose to use sky plane controls. Please note that sky plane is just one method to assemble bulk and mass of a tall building.


Applicants include:

  • Developers.
  • Architects.
  • Engineers.
  • Expediters.

Where and when

The PCPC office is located at:

1515 Arch St.
13th Floor
Philadelphia, PA 19102

Office hours are Monday through Friday, from 8:30 a.m. to 4 p.m.


When you apply for a zoning permit, the cost of a sky plane review is included in its fee.


Sky plane reviews can be conducted over the counter, without an appointment, with Philadelphia City Planning Commission (PCPC) staff.

At your review, you’ll need to present plans and other materials to prove that your project is in compliance. The major components include:

  • A zoning plan. This plan should include a table that shows compliance with blockage percentages at the regulated building height intervals.
  • Plotting sky plane diagrams for all relevant streets.
  • Your zoning permit application.

Refer to the PCPC regulations for complete submission requirements.

After PCPC staff issues an approval, you can take the approved drawings and stamped zoning permit application to L&I.