The decision to add that little “bump out” was done to create a
little more space near the house and to allow for a nicely tucked–in
set of deck stairs.
If this bump out had been framed with the joists all running parallel,
another beam 18” parallel to the house would have been required. That is
a lot digging, concrete and lumber just for a 24” bump out.
This section of the framing was designed to run perpendicular to the
rest of the deck framing and it was set into the deck over 48” so that
the force on the cantilever would not be a problem. It was a very
efficient way to build the deck design and yet keep it strong.