My operating is mostly HF QRP CW on an HW-8.
That does complicate matters a bit, especially if the building has a metal roof.
Given the bands available on the HW-8, that means mostly 40m and 15m CW,
possibly with 80m if we can squeeze in the antenna, but that isn't as likely
to be productive unless you are working at night.
The ideal thing would be to put an antenna on the roof and drop the coax down
to your office. (Even better might be to run the antenna off the side of the
roof to another support, so the wire is over the parking lot rather than the
roof.) But those aren't always easy to accomplish.
If your building has a large metal roof like many other commercial buildings, then
putting a vertical antenna of some sort up there may work well. However you
may not be able to contact the roof directly because it will be coated with
sealant, and the building maintenance staff really doesn't like people putting
screws through it. This takes some creativity.
I have worked with horizontal dipoles on top of such buildings with good results,
but you might not find much in the way of a support that gets you more than
10' above the roof. That's not too bad for local work on 80m and 40m (when the
bands permit) but the feedpoint impedance may be low due to it being so close
to the metal roof. We fixed this in one case with a shunt coil connected across
the center insulator.
If you are limited to indoors, you may have trouble finding anything that will
work well. You can try various sorts of wires strung wherever you can to
see how they work, but it will be heavily dependent on the interior configuration
of the building. If the roof is metal then you may have best results trying
vertical polarization and/or placing the antenna as close to an outside wall
as possible. If there is a large open assembly or shop area you may be able
to string up a dipole across the open space above the workers, but without
more information about what space is available to you we're really just
shooting in the dark.
