How do I claim Rent and Internet for Work-Space-In-the-Home Expenses? The tables in this form do not allow for two extra lines in the "entire home" table.

If you have indicated that some of your home office expenses apply to your entire home, and some apply only to the home office, then you will go through a series of categories where you can enter the expense based on whether it applies to the whole home or just the office.  If there is not a specific category for an expense that you have, then you will need to include it in the final category that asks for 'all other' expenses.  If you enter the total amount in the office only box, then all of the expense will be deducted.  If you enter the total amount in the entire home box, then it will be prorated according to the percent of business use of the home.

When you calculate the total area of the home office versus the whole home, either square feet or square meters may be used.  The ultimate result is the percent of the home that is used as a home office and it should be the same regardless of the unit of measurement.