Hide or Unhide Rows/Columns Based on Condition

Try this:

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Column = 24 And Target.Offset(0, -1) <> "" Then
Dim ws As Worksheet, r As Long, ch As Long, rh As Long
Set ws = Sheets("Summary"): r = Target.Row - 69: ch = 14 + r: rh = 65 + r
If Target <> "" Then
ws.Columns(ch).Hidden = False: ws.Rows(rh).Hidden = False
Else:
ws.Columns(ch).Hidden = True: ws.Rows(rh).Hidden = True
End If: End If
Application.Calculate
End Sub

The placing of the triggers seems a little awkward