Deck building cost swings enormously based on material choice, and the quote should make that choice explicit rather than bury it in a lump sum.
What to look for
- Material named — pressure-treated lumber, cedar, and composite decking occupy very different price tiers and lifespans.
- Footings and structural framing — proper footing depth (below the frost line in cold climates) is easy to shortcut and hard to inspect later.
- Permit — most decks above a certain height require one, and it's a safety issue, not just paperwork.
- Railing and stairs priced separately or included — these add up and are sometimes quoted vaguely.
If a quote is well below others, check whether footing depth and permit costs are actually included.