Use outdoor structures to prevent the spread of COVID-19

To create a shared outdoor space, follow permitting requirements, and maximize the free flow of air.

You can decrease the risk of exposure to Covid by creating an outdoor structure so people don’t have to go inside. The structure should allow the flow of fresh air. 

You must always follow local and state permitting requirements, including San Francisco's Parklet and Shared Spaces design requirements for wall heights, pedestrian visibility, and ceiling heights.

Allow free flow of air

Keep outdoor airflow in the “breathing zone” to prevent COVID-19 spread. The “breathing zone” refers to the space around a person’s nose and mouth where air passes as they breathe in and out.

The breathing zone may be at different heights for staff, clients, and customers. For example, the breathing zone for someone giving a pedicure may be different from someone receiving the pedicure.


Build structures that allow free flow of air

To reduce COVID-19 spread, according to the Shared structures manual, outdoor structures should follow these concepts:

  • No more than two sides with walls. In general, any solid vertical panel above 42 inches is considered a wall. 
  • Parallel walls which allow airflow are okay. 
  • Barriers such as a lattice fence with widely separated slats or mesh screens allow more airflow and are not considered a wall. These should not be above 42 inches to increase the view.

Structure materials 

Walls made of solid materials such as plastic, plexiglass, or acrylic block free flow of air.  Barriers with widely-separated slats or mesh allow air flow but limit visibility. 

Perimeter walls

Perimeter walls are the outside walls of the structure. The Shared Spaces permit requires perimeter walls to be a specific height for safety. Perimeter walls facing the curb cannot be higher than 42 inches. 


Using barriers between dining tables inside the structure creates more privacy but reduces healthy airflow.  To allow free flow of air in the breathing zone, use a solid barrier for only one side. 

Overhead coverings

Ceilings, roofs, umbrellas, and other coverings allow airflow if most of the structure walls are less than 42 inches.  They must be at least 7 feet from the ground.


Last updated June 27, 2022