As the permit manager for dozens of projects each year in Chicago, we know that getting a desired address for a new residential or office project can be very important to a client. When clients are unable to obtain their preferred address (or a vanity address), this can result in stress and inefficiency.

The most common situation we see that is a client starts marketing the address of their new project before receiving the House Number Certificate from CDOT. This tends to lead to elongated discussions to try and obtain the marketed address. In some situations, the address has had to change in between the time the developer began marketing the project and the point when the building permit was issued.

In the City of Chicago, the Department of Transportation’s (CDOT) Public Way Maps and Plats section certifies addresses for new construction building permits and issues House Number Certificates. The addresses are issued according to the position of the new building’s main entrance along a street block and according to official city maps.

We offer this strategy to our clients so that the CDOT-approved future address is aligned with your branding and marketing efforts.

Tips for getting the perfect address

CDOT uses “80 Acre” sheets (plat maps) to help them determine a new building’s address. These sheets show the extents of house numbers on each block in the City and maintain the record of Chicago’s grid-based addressing system. Anyone can look up the 80 Acre sheet containing a building by looking up the location on the Chicago zoning map and see the address which corresponds to the location of a potential main entrance.

This image shows part of an 80 Acre map of a downtown block. The range and position of house numbers are shown on the bottom edge of the block and marked by pink arrows.


CDOT will only issue a House Number Certificate for an address that represents the main entrance’s location. This is important not just for mail and directions to people trying to access your development, but also for firefighters looking for the fire command panel. If the building’s address is 123 Main Street, the main entrance and the fire command panel must be located at exactly 123 Main Street, and not on a side entrance. If Main Street has numbers going from 100 to 150, then the entrance at 123 Main Street would be close to the middle of the block.

Assemble your documentation

You’ll need the following documents to apply for a House Number Certificate:

  1. Site plan showing the dimensions from each main entrance (retail, residential, office, etc.) to the property line

  2. A survey, no more than six months old, signed and sealed by the surveyor

  3. Contact info for the owner/developer applicant and their expeditor

Look up your potential address on the 80 Acre map

Use the City of Chicago’s zoning map to locate the relevant page on the collection of 80 Acre maps. You can also contact MAPS and Brandon Clementi, one of our super-helpful project managers, will look up potential addresses.

 A sample of a House Number Certificate.

A sample of a House Number Certificate.