A new composite deck with built-in seating turns a basic backyard into a second living room. You will stop worrying about wood rot and sanding, and start using the space for coffee or evening hangs almost immediately.
Book your builder in late autumn. Pros are looking for work when the weather turns, which makes them more likely to negotiate on labor costs. The physical build usually takes less than a week, so you can have it ready before the first frost.
The 18-month window is a deadline, not free money. If you have a remaining balance after the intro period ends, the interest charges will kick in on the remaining amount, which will cost you extra.