The rent that you pay your landlord and utilities should be split between Schedule C and Schedule E. You can't use it all as a business deduction on Schedule C if that space is not being used for your business.
I'm not sure what TurboTax does with the 100% question, but I would say you own 100% of the building and manually calculate the rental portion of the rent and utilities. You may be able to enter just the rental percentage and enter the FULL amount of utilities and rent, but I'm not 100% positive. Make sure you do NOT claim depreciation on the building.
