Deck & Porch Permit

• May not be constructed in public utility or drainage easements.

• Unroofed decks/porches must remain at least 3 ft. from the property line, if there are no easements.

• Unroofed decks/porches may extend into the required front yard a maximum of 10 feet.

• All closed roofed structures may cover no more than 30% of the lot.

• Attached closed roofed structures must remain at least 6 ft. from other roofed structures.

• Setbacks for attached roofed decks/porches vary depending on the home’s zoning classification.

• No roofed deck or porch is allowed in the required 20 foot corner side yard.

• Deck size

• Size and spacing of floor joists

• Size and location of concrete post holes

• Size and location of support posts

• Size of all headers and beams

• Size of ledger board and number and spacing of lag bolts, flashing, guardrail and handrail design and spacing and height.

• All post holes are to be a minimum of 42” below grade when deck is attached to house; post holes for free-standing decks are to be a minimum of 24" below grade.  Post holes should be a minimum 10" in diameter.  All supporting deck posts are to be a minimum of 6x6 exterior grade material.  Lateral load connections are required on all decks that are not self-supporting and that exceed 30" from grade.

• All lumber for deck shall be of approved wood, of natural resistance to decay or treated wood. Hot-dipped galvanized or stainless steel fasteners and joist hangers and galvanized or copper flashing are required.

• Decks greater than 30” above grade shall have a guardrail.

• Guardrails will be a minimum of 36” in height with 4” maximum spacing between balusters on stairs and decks.  Balusters cannot be horizontal.

• Stairways shall be a minimum of 36” wide with a maximum riser of 7 ¾” and a minimum tread size of 10”.  The risers need to be consistent, and closed (solid).

• A gripable handrail is to be provided to all stairways having four or more risers.

• Gripable handrails shall be placed not less than 34”, no more than 38” above the nosing of the treads with 4” maximum spacing between balusters on stairs and decks. They shall be continuous the full length of the stairs.

• Floor joist spacing at 24” on center require a minimum of 2x decking and floor joist spacing at 16” requires 1X decking. Engineered decking products to be installed per manufacture’s instructions.

• INSPECTIONS ARE REQUIRED BEFORE CONCRETE IS POURED AND WHEN A DECK IS FINISHED, COMPLETE WITH GUARDRAILS AND HANDRAILS WHEN REQUIRED.       

An accurate plat of survey is required for all permits for installation of, replacement of, and additions to fences, decks, pools, patios (with or without a roof), driveways, driveway aprons, sidewalks, garage/ carports, pergolas and similar structures, and additions. This includes the replacement of flatwork (driveways, aprons, sidewalks) with the same dimensions and location.

If you’re having troubles locating your Plat of Survey, refer to these options:

1. Closing Papers from Purchase of Property.

2. Contacting the Mortgage Company.

3. FOIA (Freedom of Information Act) Request with the City of Joliet City Clerk’s Office.

Note: This option may only yield results if the plat of survey was provided to the City of Joliet in the past for a building permit or a special zoning approval.

You may also try calling Local Surveying Companies for possibility of a previous copy or to get a new plat of survey.

Note: The City of Joliet is not responsible for keeping plats of survey on file.