I realize this is an old post but these home office questions tend to get some information that's not entirely accurate.
You can use the simple method since you don't have any expenses. However if you are not profiting from your business then you are not able to incur or carry forward any loss from the home office.
To use actual expenses you will need to either pay them rent, pay the utilities, property taxes, mortgage interest, or some expenses toward the house that you can use.
