12x20 Deck Plans
Twenty feet wide across the back of the house and twelve feet deep. The shape to build when the yard is shallow but the wall is long: 240 square feet without pushing far into the lawn. That width is what drives the beam to three plies of 2x12.
It is drawn on a generic lot, so the site plan here does not show a real property. When you run your own address, we pull your parcel, lot shape, and setbacks from public records and redraw the whole set around your actual house.
Deck specifications
| Deck size | 20'-0" x 12'-0" (240 sq ft) |
| Height above grade | 4'-0" |
| Attachment | Ledger to house band joist |
| Joists | 2x8 at 16" on center |
| Beam | 3-ply 2x12, dropped |
| Footings | 16" diameter piers, 36" deep (4) |
| Decking | 1x6 composite |
| Guard rail | 36" Fortress rail system |
| Stairs | One straight flight, front edge, 4'-0" wide |
| Design loads | Moderate snow, cold frost zone |
What is in the 7-sheet set
Every sheet carries a title block, and every structural member cites the 2021 IRC section it was sized from. These are not stock previews. They were drawn by the same pipeline that will draw yours.
Using this for a permit
Most building departments want a site plan showing the lot, house, deck, and setbacks, plus a framing plan, elevations, structural details, general notes, and the ledger attachment detail. This set has all of them. Download the sample to see exactly what a reviewer would be looking at, then generate the same set against your own lot.