Of course when all else fails check the IRS pubs ... quote from pub 704:
Depreciable or Not Depreciable
The kinds of property that you can depreciate include machinery, equipment, buildings, vehicles, and furniture. You can't claim depreciation on property held for personal purposes. If you use property, such as a car, for both business or investment and personal purposes, you can depreciate only the business or investment use portion. Land is never depreciable, although buildings and certain land improvements may be.
You may depreciate property that meets all the following requirements:
- It must be property you own.
- It must be used in a business or income-producing activity.
- It must have a determinable useful life.
- It must be expected to last more than one year.
- It must not be excepted property. Excepted property (as described in Publication 946, How to Depreciate Property) includes certain intangible property, certain term interests, equipment used to build capital improvements, and property placed in service and disposed of in the same year.
