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Size Threshold

What Size Deck Can I Build Without a Permit?

The 200 sq ft rule explained, where it applies, and the design options that stay under the threshold.

By Brian Williams

Quick Answer: Most US cities exempt decks under 200 square feetfrom permits — but only when the deck is also freestanding, under 30 inches above grade, and not in a special zone. 200 sq ft alone is not enough.

Deck Sizes That Stay Under 200 Sq Ft

Design targets that keep you under the threshold (aim for 190 sq ft max to absorb measurement tolerance):

DimensionsSquare FeetNotes
8x24192Long and narrow. Fits a dining table with chairs.
10x19190Nearly-rectangle. Common retrofit size.
12x16192Most popular under-200 design. Comfortable for a seating area plus grill.
14x14196Square, maximizes usable area. Harder to design around existing doors.
10x20200AT the threshold. Most cities treat this as over, not under.
12x17204Just over — needs a permit.
14x15210Just over — needs a permit.

The Full Exemption Requires More Than Size

200 sq ft is necessary but not sufficient. Most cities require all of these together:

Under 200 square feet

Total deck footprint including stairs and landings.

Under 30 inches above grade

Measured at every corner, not just the average. Sloped yards often violate this.

Freestanding

Not attached to the house with a ledger board. This is the single most common disqualifier homeowners miss.

No utilities

No electrical outlets, no lighting wired to household circuits, no gas lines for grills or fire pits, no plumbing.

Does not serve a required exit

If the deck is the path from a bedroom egress window or basement walkout, it regulates as means of egress regardless of size.

Not in a flood zone, coastal zone, or historic district

Special zoning overrides size exemptions.

State-by-State Patterns

Verify with your local building department — cities amend state code routinely.

StateThresholdNotes
California200 sq ftState code follows. Cities may be stricter (SF exempts nothing).
TexasVaries by cityMost major Texas cities follow the 200 sq ft pattern.
Florida200 sq ft (most jurisdictions)HVHZ counties require permit even for exempt-size decks.
New YorkVariesNYC: no exemption. Upstate: usually 200 sq ft.
Pennsylvania200 sq ft under PA UCCMust also be under 30" above grade and not attached.
Ohio200 sq ftOBC follows IBC/IRC exemption.
IllinoisVariesChicago: no exemption. Suburbs usually 200 sq ft.
Michigan200 sq ftMust be freestanding and under 30" above grade.
North Carolina200 sq ftNC Residential Code follows IRC exemption.
Georgia200 sq ft (most counties)Varies; Atlanta has local amendments.
Washington200 sq ftWAC 51-51 follows IRC. Seattle may differ.
Colorado200 sq ftDenver may require permit for attached decks regardless of size.

Design Trade-offs at 200 Sq Ft

Staying under the threshold shapes the deck. Common trade-offs:

What fits under 200 sq ft

  • • Outdoor dining table for 6 plus circulation
  • • Grill + prep counter + 4-person table
  • • Lounge chairs (4) plus small side table
  • • Small deck + walkway to a separate firepit area

What does NOT fit under 200 sq ft

  • • Full outdoor kitchen (grill + sink + refrigerator island)
  • • Dining for 8 plus separate lounge area
  • • Hot tub on the deck (hot tub itself is ~50 sq ft plus access)
  • • Wraparound deck on two sides of the house

The design-around-the-threshold trap

Designing right at 199 sq ft to dodge a permit is a false economy. You get a deck that's half a foot smaller than what would have been useful, the permit savings are maybe $200, and any future measurement discrepancy (including expansion you might regret skipping now) exposes you to retroactive permit fees. If your ideal deck is 10x22, just pull the permit for the 220 sq ft version.

Frequently Asked Questions

Why 200 square feet specifically?

200 square feet appears in IRC Section 105.2 as the threshold for permit-exempt small residential buildings and structures, and most jurisdictions carry that number over to decks. The threshold balances the city's administrative cost against the structural risk of a small deck. Above 200 sq ft, plan review becomes worthwhile.

Does 200 sq ft include the stairs?

Generally yes in most cities. The measurement is usually the total footprint of the deck including any attached stair landings. A deck that measures 199 sq ft of main surface plus a 36"-wide stair landing probably exceeds 200 sq ft when measured footprint. Verify with your local building department.

Is a 10x20 deck exactly at the threshold?

A 10x20 deck is exactly 200 sq ft. Most cities write the rule as "under 200" (strict less-than), meaning 10x20 crosses the line. Design to 9.9x20 (198 sq ft), 10x19 (190 sq ft), or 8x24 (192 sq ft) if you want to stay under. Round numbers like 10x20, 12x16, 14x14 all put you at or over the threshold.

Can I build two 200 sq ft decks and call it two projects?

No. Cities look at total contiguous deck area. Two connected platforms are one deck for permit purposes. Some homeowners try building in phases ("I built 150 sq ft last year, adding 100 sq ft this year") but cities treat the combined structure as one permit decision. You now have a 250 sq ft deck that needs a permit.

Does the 200 sq ft rule apply even if the deck is attached to the house?

Usually not. Attachment to the house almost always triggers a permit regardless of size. The 200 sq ft exemption typically requires the deck to be freestanding. A 100 sq ft ledger-attached deck often needs a permit; a 199 sq ft freestanding deck often does not.

What about decks over 200 sq ft — is there another threshold?

Above 200 sq ft, permits are effectively universal. Some jurisdictions have additional thresholds at 500 sq ft (requires engineered drawings) or 1,000 sq ft (requires a structural engineer's stamp). For typical residential decks, crossing 200 sq ft means you need a permit; the higher thresholds add complexity, not exemptions.

Is the 200 sq ft rule in the IRC?

Not directly. The IRC delegates permit requirements to the adopting jurisdiction. IRC Appendix H (for accessory structures) uses 200 sq ft in some editions. The International Building Code (IBC) Section 105.2 lists "one-story detached accessory structures not exceeding 200 square feet" as an exemption. Most cities align with this number.

Can I get the exemption if I design for 199 sq ft?

On paper, yes. In practice, cities often measure the as-built deck during a future property transfer or inspection. If the actual dimensions measure to 205 sq ft, you will be cited for unpermitted work. Design with a safety margin (190 sq ft max) if you want to rely on the exemption.

Size thresholds vary by jurisdiction. Always verify with your local building department before building.