Wood decks built for this climate.

Almost every deck that fails here fails from underneath. Joists that trap water against the ledger, posts set shallower than they should be, hardware that was not rated for treated lumber and bled rust through the boards inside a season. None of that is visible from the surface, which is why a deck can look sound and be halfway gone. Footings below the frost line, joists spaced and flashed so water drains rather than sits, and hardware chosen for the lumber it is going into — that is where the years come from, and it is the part that cannot be put right later without taking the deck apart.

Treated pine is the economical choice and takes stain and sealer well. Cedar costs more, holds its shape better, and resists insects and rot with less help. On a big deck the difference in material cost is real, which is why plenty of builds split the two: treated pine for the framing nobody sees, cedar or composite for the surface underfoot. Which way it goes usually comes down to the size of the deck and how much upkeep you want to sign up for.

A platform a step off the ground and a deck at first-floor height are different builds at identical square footage. Height brings guard rails, heavier posts and stairs, and stairs are their own piece of work — rise and run have to be consistent, they need their own footings, and they are where code pays closest attention. Worth knowing before comparing quotes, because two numbers for "a 16 by 20 deck" can be describing very different jobs.

Where the sun lands in the afternoon, where the door comes out, whether you want the grill away from the seating, and whether the space has to work in August. Those answers shape the deck more than the square footage does. Multi-level layouts solve a sloping yard and also break a large deck into areas that get used differently. It is worth walking the yard and talking it through before drawing anything.