Generating Elevations - AutoCAD 2011 and AutoCAD LT 2011: No Experience Required - page 523

FiGuRE 10.18 Vertical construction lines drawn from deck post, stairs,
and railings
FiGuRE 10.19 The offset lines for the stairs
6. Start the TRIM command and select the two post lines, the soffit line,
and the third horizontal deck line (deck surface) from the bottom as
the cutting edges (see Figure 10.20).