1031 exchange requirements

[Nat C.]

I have an upcoming property sale and I was planning to do a 1031 exchange with it.

The property being sold was a development project, which I was never able to finish. The property has never been rented during my course of ownership.

A CPA told me today that it may not be eligible for a 1031 as it was never rented out. My understanding was that you could do a 1031 exchange with ANY investment property, whether it be a development project, land, commercial premises or residential rental property. I was under the belief that the only ineligible property is one which was your primary residence because the purpose of the 1031 tax code is to encourage investment.

Can anyone here enlighten me as to whether I am incorrect with this?