Here is the short answer: if your deck needs a permit, your application almost certainly needs a site plan. It is usually the first document on the checklist and the one most likely to stall an application when it is missing or incomplete.
If you already know you need the drawing, a deck site plan is drawn to your lot from county records and delivered in 24 to 48 hours from $89, with free revisions until your building department accepts it. The rest of this page is when a deck needs a permit at all, what the reviewer checks, and what both cost.
Why the deck permit and the site plan travel together
A deck permit application really asks two questions. The construction drawings answer "will it stand up?" The site plan answers "is it allowed to be there?" That second question is about setbacks, lot coverage, and easements, and the only way a plan reviewer can answer it from a desk is a to-scale drawing of your lot with the deck on it.
That is why the site plan requirement is nearly universal wherever deck permits are required at all. Most US cities require a permit for decks that are more than 30 inches above grade or larger than about 200 square feet, and the deck permit rules vary meaningfully by state, but the drawing requirement follows the permit almost everywhere.
When a deck permit is required, by the numbers
Decks have the most consistent trigger of the five common projects, and it is a height, not an area. Across all 51 state guides on this site:
- 38 of the 51 describe the 30 inches above grade rule as the common threshold, which comes from the model residential code language most states adopt.
- 24 of the 51 add a floor-area line as well, most often at 200 square feet.
- Attachment to the house is a separate trigger in many jurisdictions. A ledger bolted to the dwelling brings the deck into the building permit even when it sits low enough to be exempt on height, because the connection is a structural question about the house.
The practical read: a low, freestanding platform is often exempt, and almost anything you would put a railing on is not. Your city sets the number that binds at your address, and the deck permit rules by state collect the state-level patterns.
What a deck permit costs and how long review takes
From the 250 tracked city records behind our state guides:
- Median permit fee: about $162, with the full range running from $35 in the cheapest tracked cities to roughly $1,000 where the fee is calculated from project valuation.
- Typical review: about two weeks at the median upper bound, with counter approvals in some cities and up to twelve weeks in the slowest.
Your city's own number is in the permit cost calculator, and the full comparison is on the building permit cost page.
What your deck site plan has to show
The reviewer's checklist for a deck is short and concrete:
- Property lines with your lot dimensions written along them
- The house and existing structures, so lot coverage can be verified
- The deck itself, drawn to scale in its exact location, with length and width labeled
- Setback distances: the measured gap from the deck edge to each property line, written as numbers
- Attached or freestanding, made obvious on the drawing, because the two are often reviewed under different rules
- The basics block: north arrow, stated scale, parcel number or address
Miss the setback numbers and the application usually comes back with a correction notice. That single omission is the most common reason deck applications stall.
Attached or freestanding, and why the reviewer cares
Making this explicit on the drawing matters more than it looks, because the two paths diverge immediately:
- An attached deck transfers load into the house through a ledger board. That pulls the house's structure into the review, adds flashing and fastener details, and in most jurisdictions means the deck cannot be exempt regardless of its height.
- A freestanding deck carries its own load on its own posts. It is reviewed as an accessory structure, and in many places a low freestanding platform skips the building permit entirely while still having to satisfy setbacks.
Reviewers should not have to infer which one you are building from a footprint outline. One label on the plan settles it, and it is a common enough omission that it is worth checking twice. If the deck is attached, say so in words next to the house wall it connects to, not just by drawing the two shapes touching.
Footings, frost depth and what belongs on the other drawing
A frequent source of confusion: the site plan says where the deck goes, and a separate construction drawing says how it stands up. Footing depth belongs to the second one, but it is worth understanding before you design, because it is the deck requirement that varies most across the country.
Footings generally have to bear below the local frost line, and across the 41 state guides on this site that publish a figure, the range runs from about 12 inches in the warmest states to 48 inches or more in the coldest. Maine and Massachusetts sit at the top of that range; Alabama and Arkansas at the bottom. Two identical decks, one in Alabama and one in Maine, need meaningfully different foundations, and a plan set copied from a generic online template will be wrong in one of those places.
Some departments do ask for footing locations to be marked on the site plan as well, usually so the inspector knows where to look on the first visit. It costs nothing to add and it is on more checklists than you would expect, so check yours before you submit rather than after.
Five corrections that send deck plans back
- No setback numbers written on the drawing. The most common single reason a deck application stalls. The deck may be in a perfectly legal position, and nothing on the page proves it.
- Height above grade not stated. Since the permit trigger itself is a height, a reviewer who cannot see that number cannot confirm which rules apply.
- Attached or freestanding left ambiguous, per the section above.
- Stairs and landings left off. They project further than people expect, and the setback is measured to the nearest point of the structure, which is often the bottom step rather than the deck edge.
- Easements not shown. Recorded on the plat, invisible in the yard, and the correction that most often forces a redesign rather than a redraw.
If the deck is already built
A fair number of readers arrive after the fact. The path exists and it starts with the same drawing: retroactive permits covers legalizing work already done, and what happens if you build without a permit sets out the realistic range of outcomes. If a contractor told you no permit was needed, that conversation has its own guide.
The fastest way to get one
For most homeowners the practical route is a drafted plan: a deck site plan runs $89 to $259 and arrives in 24 to 48 hours, drawn to scale from county GIS records and satellite imagery with your deck dimensioned and every setback labeled, plus free revisions until your building department accepts it.
If you would rather draw it yourself and your city accepts hand-drawn plans, the honest budget is two to four hours: our six-step walkthrough covers the whole method, and the Pre-Submission Checklist is the quality gate before it goes to the counter. Just know the trade: the afternoon is free, the redraw cycle after a correction notice is not.
Before you submit anything
Check your city's own checklist. Some departments want the deck's height above grade noted on the plan, some want footing locations shown, and coastal or wildfire-zone jurisdictions add items. Two minutes on your building department's website, or one call to the counter, beats a week in the resubmission queue. Ask specifically whether they accept hand-drawn plans, whether they want footing locations marked, and whether the deck's height above grade has to appear on the site plan itself. Those three answers determine almost everything about how you prepare the drawing.
For the permit side of the project, start with the deck permit guide and your state's page. For the drawing side, the complete guide to site plans for permits covers everything on this page in more depth.