Check local building codes and permit requirements
Measure deck height, landing space, and available run
Choose stair location and confirm clear access
Determine total rise from deck surface to grade
Calculate number of steps and uniform riser height
Calculate tread depth and stair slope
Select pressure-treated lumber or approved exterior materials
Mark and cut stair stringers accurately
Install stringer hangers or support brackets if needed
Attach stringers securely to the deck frame
Set the bottom of the stringers on a concrete pad, footing, or landing
Install stair treads on the stringers
Install risers if required by code or design
Add handrails and guardrails where required
Secure all fasteners with exterior-rated hardware
Check each step for level, spacing, and stability
Seal, stain, or paint exposed wood as needed