The best way to claim this deduction is to use an accountable plan.  The accountable plan requires that you, the owner, employee must incur the expenses in the performance of your duteis for the corporation and substantiate the expenses to the corporation in accordance with the tax law.

To substantiate the expenses you will need to show –

1. Exclusive and regular use of the office in your home

2. Use of the office for the convenience of your employer

3. Use of the office as a principal place of business and

4. Expenses to be reimbursed including depreciation.  These can be calculated using IRS form 8829.