Is the term "White House" often used to refer to anything within the executive branch? I have always assumed it meant the office of the President and perhaps his cabinet...
To answer your question yes, in general, actions taken with direct authority or direction from high-level appointees of the President are described by the media as "White House" actions, with good reason.
[1] http://www.justice.gov/crt/about/app/briefs/fisher_appellee_...
It does not include law enforcement or intelligence agencies, nor cabinet-level departments. So "White House" does not mean FBI, DEA, Department of the Interior, etc. However, the term "Administration" or "<President's last name> Administration" does include these entities.
That would mean most non-cabinet and "independent" agencies -- all of which are part of the executive branch and not part of a cabinet-level department -- would be part of the "White House", which assuredly is not the common use.
Usually, it means specifically the Executive Office of the President. (Rarely, it might even more specifically mean the White House Office, which is within the Executive Office of the President and, like the Executive Office, also headed by the White House Chief of Staff.)
> So it includes the Executive Office of the President, the OMB, ONDCP, DoJ, etc.
OMB and ONDCP are part of the Executive Office of the President. [0]
DoJ (which, relevant to the thread, includes the Office of the Solicitor General) is a cabinet-level department (headed by the Attorney-General), and so even if your excessively-broad "outside the cabinet-level departments" rule was correct, would still be excluded.
[0] http://en.wikipedia.org/wiki/Executive_Office_of_the_Preside...
http://www.wired.com/2014/12/obama-becomes-first-president-w...
Well, no, the Solicitor General, under whose authority such things are done (and who is the person to whom the Supreme Court issues -- as it did in this case -- "invitations" [treated as commands] for input), is one of the highest-ranking officers at DoJ.
And still not part of the White House.
Only when people are being sloppy, either through ignorance, or, e.g, because its convenient for spin they'd look to put on something.
Less sloppily, referring to an entity rather than a building, it refers to either the White House Office within the Executive Office of the President, or the whole Executive Office of the President (both of which are headed by the White House Chief of Staff.)
'Sloppy' seems the wrong word to use to me.