Size it by furniture, not by square footage
Draw the actual furniture: table, chairs pulled out, grill with clearance, and a walking path around all of it. Most undersized decks were sized by budget and then found unusable for the thing they were built for.
The connections that matter
- Ledger attachment and flashing where the deck meets the house
- Footing depth and diameter for local soil
- Joist hangers and fasteners rated for treated lumber contact
- Guardrail post attachment, which is a structural connection, not a trim detail
- Stair stringer support and consistent rise
Material comparison
| Pressure-treated wood | Composite |
|---|---|
| Lower up-front cost | Higher up-front cost |
| Requires periodic cleaning and sealing | Requires cleaning, not sealing |
| Can be stained any color later | Color is chosen at purchase |
| Moves and checks with weather | More dimensionally stable |
| Framing requirements standard | May require closer joist spacing |
Think about how the deck meets the yard
A deck that ends in a single step onto a muddy slope is used less than one that transitions to a patio or landing. On sloped lots, a combined deck-and-patio approach usually creates more usable space than either alone.
Cover it or not
A roof structure dramatically increases how many months a deck is used and changes footing loads, permitting, and cost. Decide before framing, because retrofitting a cover onto a deck not designed for it is rarely straightforward.
Permits
Most jurisdictions permit decks above a certain height. Skipping the permit tends to surface at resale, when it's far more expensive to resolve.
- Lay out real furniture before choosing dimensions.
- Ledger flashing and footing depth determine lifespan.
- Choose covered vs. uncovered before framing, not after.
- Composite is a maintenance decision, not a quality upgrade.