Whether your use of the space is for the convenience of your employer depends on the facts and circumstances of your case. If your employer provides you with an office at work, very likely your use of the space at home is not for the convenience of your employer. On the other hand, if your employer doesn't provide you with an office and requires you to work elsewhere, it probably is for your employer's convenience.

Examples:

• A sales representative shares an office at work with other salespeople. She works at home because there are no disturbances, but she is not required to do so. She should click No.
• A sales representative is in the field all day and not available by telephone. As a result, he is required to spend two hours per night on the telephone with customers from his home. His use of his home probably is for the convenience of his employer.