Deck products

Stairs are the biggest add-on and the most code-governed. Beyond price, know the geometry: 2x12 minimum stringers, 36-inch minimum width, riser maximum 7 3/4 inches, tread minimum 10 inches, and no more than 3/8 inch variation between them. Stairs with four or more risers need a handrail 34 to 38 inches above the nosings. Total stair rise of 30 inches or more triggers a stair guard at 34 inches minimum from the nosing.

Lighting is partly a code item, not just an upgrade. Stairways must have a light source at the top landing illuminating all stairs and landings, switched from inside the house, with motion or timed switches acceptable. Decorative post-cap and riser lighting is optional; the stair light is not.

Skirting, lattice and under-deck drainage all deal with the space beneath the deck. Two cautions: keep ventilation and access, because trapped moisture is what rots framing, and remember footings must not be built over septic systems, leach fields, utility lines or enclosed meters — which sometimes constrains what can go underneath.

Built-in benches and planters look like furniture and behave like load. Planters in particular hold water directly against the decking. If you want them built in, ask how the framing was adjusted and how water drains away from the boards.

How to choose

Count your stair treads before you budget

At $75 to $450 per step depending on construction, stairs are a per-unit cost, not a rounding item.

Get stair lighting quoted in the base bid

It's required at the top landing, so a bid that omits it is an incomplete bid, not a cheaper one.

Don't seal the underside of the deck

Skirting that blocks airflow traps moisture against the framing. Rot repair runs $300 to $5,000.

Put planters on feet, not flat on the boards

Standing water under a planter is the most common start point for board rot.

Add-ons can wait; framing can't

Lighting, skirting and benches are retrofittable. Undersized joists are not.