Collin County · Texas
Allen site plans and permits.
Allen follows the standard code exemption: small, low, freestanding decks don't need a permit.
Building code
2021 International Residential Code.
Deck permit
You need a permit unless the deck is 200 sq ft or smaller, no more than 30 inches above grade at any point, freestanding and not serving the required exit door.
Sheds
A one-story detached shed or playhouse of 120 sq ft or less doesn't need a permit, as long as it respects drainage easement rules.
Owner-drawn plans
The city's pages don't say who may draw deck plans.
Setbacks
We didn't find published setbacks. Keep structures out of private drainage easements.
Where to apply
Checked against the city's own pages on October 30, 2026. Rules change, so confirm with Allen before you submit.