Cheaper to build rooms in attic or basement
I know it will be difficult to answer this question with specifics, but we are planning to build a home in Ohio and are struggling to decide if we should include extra bedrooms in the basement or the attic. All the main rooms (including the master bedroom) will be on the first floor. The main floor will be approximately 1700 square feet. These are our two options for the two other bedrooms and bonus room we would like to include:
1. Build 1.5 story home with two bedrooms, a bath and a bonus room in the 1/2 story. This option would include an unfinished, non-walk-out basement. We would have 1 dormer on the front of the house; other egress windows would be in the gable ends.
2. Build 1 story home with finished, walk-out basement. Two bedrooms, bath and bonus room in basement. No dormers required in roof.
Basically I'm wondering, in general, if it is cheaper to finish off the basement or the attic space - taking into consideration the roof design (trusses or stick-built), insulation, moisture control, etc. I've tried searching for answers to this, but mostly have found responses that deal with finishing an already existing attic or basement. I'm wondering which option is cheaper if planned from the initial build.
Thank you for your help!