Cost Segregation is the IRS recommended method to depreciate your building rather than the standard 39 year method. If you have acquired, built, renovated or completed lease hold improvements on your office in the last 15 years, all of those building components can be accelerated into 5, 7, and 15 year lives. About 25% of a buildings components are depreciable in the first five years. Here is the link to an overview: http://cashflow.costsegserve.com/taxsavings/ ...that explains the history of the application and introduces my firm. It may mean a substantial tax benefit, (usually $35K to $45K for every $500K in building costs in the first 5 years) if you qualify. It is to your advantage to familiarize yourself with the basic concept of this application. Let me know if I can help you with additional information.