@Carl The IRS does not recognize a Schedule C business as being separate from its owner. They are one and the same. So even it the "business" is renting the place, the IRS sees it as the PERSON renting the place.
So the PERSON has to allocate expenses between what it is used for, (1) personal use, (2) business use (Schedule C) and (3) rental use (Schedule E).
The rental of office space is not subject to self employment taxes (assuming that "services" are not provided), so the rental does not go on Schedule C at all.
