Do I have to pay capital gains tax on an empty lot?

[Rapy Narruhn]

If I already have a home of my own and I would like to sell a empty lot separate from the lot my home is on, how does capital gains tax play in this? I did some research and saw that since I've owned the property for more than a year, I will only pay 15% in capital gains instead of the usual 30-35%. I just wanted get more inputs. If anyone knows a CPA they would recommend in Portland, that would be much appreciated. 

Thank you!