As you can see, many answers here but one familiar answer is read your lease. The initial term is what you want to know.. is it 20 years? Or is it 5 years with 3 available optionals to renew for 5 years each to total 20 years? Most major credit tenants will sign long term 20 years lease with additional options to renew at x% increases. For instance, CVS will sign a 25year term with 10 options to renew at 5 years each option. There by equating to a total value of 75 years if CVS takes all options. Walgreens is similar however the wording on the lease states that it is a 75 year lease, but the Tenant has the option to terminate after the 25th year, and every subsequent 5 years. Thereby the lease is effectively a 25year lease with 10 options to renew.
Bottom line: read the lease and understand what the initial term will be, and how many options to renew and at what duration each option and at what rate or increase.
Hope this helps.
Jul 28, 2011