Deck permits, explained

Do you need a permit for your deck?

Start from the exemption, because everything else needs a permit. In the International Residential Code (IRC), Section R105.2 lists the work that does not need one. For decks, all four conditions must be true at the same time^[1]:

• the deck is 200 square feet or less;
• it is no more than 30 inches above grade at any point;
• it is not attached to the house;
• it does not serve the exit door the code requires for the home.

Miss one condition and the exemption is gone. A 12 by 16 foot deck is 192 square feet, so it passes on size, but if it is bolted to the house, or stands higher than 30 inches anywhere on a sloping yard, it needs a permit.

The exemption is not a free pass, and it is only the model code. Federal Way, Washington, which publishes the list, adds that separate permits may still be required for exempted items, and that any work in a critical area, such as wetlands, streams or landslide hazard areas and their buffers, is not exempt^[1]. Other places go further: Fairfax County, Virginia, names decks and porches among the common projects that need a building permit, along with sheds and other detached structures over 256 square feet, and notes that Virginia law requires both permits and passed inspections^[3].

What the city asks for

A deck permit application is mostly drawings. The list from Hastings, Minnesota, is typical of what a building department wants to see^[2]:

1. A site plan: a scaled drawing that shows where the deck sits on the lot, with its distances from the property lines, utility easements, power lines and other structures.
2. A deck plan, with dimensions and materials, covering the footings, the ledger, the beams, the joists, the decking and the stairs.
3. An elevation drawing showing how high the deck stands above the ground.
4. An owner-contractor waiver if you build the deck yourself.

The site plan is where the city checks the distances between your deck and your property lines. That is why the same deck can be fine on one lot and refused on the next.

Deck permit drawings

The American Wood Council publishes a guide to deck construction, known as DCA 6. It describes a framing plan as the drawing that shows the width, the length, the joist and beam layout, the location of the ledger board, posts and footings, and the type, size and spacing of the ledger board fasteners^[6].

DCA 6 has limits worth knowing before you draw anything. It applies to single-level residential wood decks attached to the house to resist lateral forces, and decks supporting large concentrated loads, such as hot tubs, are beyond its scope^[6]. A two-level deck or a deck with a hot tub falls outside this guide and may need an engineered design.

Your drawings must also show the guards. In Hastings, for example, all decks 30 inches or more above grade must have a guardrail at least 36 inches high^[2].

The inspections

The permit is not the end: the inspector visits during construction. Hastings lists three steps^[2]:

• Footings, inspected and approved before any concrete is placed;
• Framing, as a separate inspection for decks under 60 inches above grade;
• Final, which must be completed before the deck can be used.

Plan your work around them: pouring concrete before the footing inspection skips a step the city requires.

What a deck permit costs

Fees are set by each city, and they are published. Two real examples:

In Canandaigua, a 12 by 16 foot deck (192 square feet) works out to $57.60, so the $100 minimum applies^[5]. Other permits are often priced on the value of the work: the same Oakdale schedule sets value-based building permits and a plan review fee of 65% of the permit fee for them^[4]. Your permit file shows your own city's fee, from its fee schedule, with the link.

How long it takes

There is no national average worth quoting: review times depend on the city, its workload and how complete the application is. What you control is the first submission: an application with a complete site plan and readable drawings avoids the correction requests that restart the clock.

Building without a permit

Skipping the permit does not make the question go away. Fairfax County applies its rules on unpermitted construction to homes that were bought and sold, regardless of when the construction was done^[3], so an unpermitted deck can surface when you sell, or when you buy. Fixing it later costs money: in New York City, legalizing work done without a permit on a one- or two-family home carries a $600 civil penalty, and removing the work instead carries the same penalty^[7].

Already built your deck?

Talk to your building department before anything else: it decides whether and how work done without a permit can be legalized, and what must be shown, opened up or changed. Expect a cost on top of the normal permit fee: in New York City, legalizing it is the $600 penalty mentioned above^[7].

Common questions