@TaxMonkey and @abctax55 know that it depends on whether the taxpayer is itemizing or claiming the standard deduction.  Read all of Pub 587:

Certain expenses are deductible to the extent they would have been deductible as an itemized deduction on your Schedule A or, if claiming the standard deduction, would have increased your standard deduction had you not used your home for business. If the expense is indirect, use the business percentage of these expenses to figure how much to include in your total business-use-of-the-home deduction. If you are itemizing your deductions on Schedule A (Form 1040), these expenses include the following.
• Real estate taxes.
• Home mortgage interest.
• Casualty losses attributable to a federally declared
disaster.
If you are claiming the standard deduction, these expenses only include net qualified disaster losses that increase your standard deduction.