My husband and I are both self-employed and have separate home offices. Should we both enter home expenses i.e. heat, mortgage interest , etc. on the home expenses page?

Yes you can both enter in home expenses for each person. However, amounts like heat, mortgage etc should be pro-rated to the amount of space you use in the house. For example, if you use one room out of ten rooms in the house, you can claim 10% on utilities/mortgage interest etc. If your husband uses, two of the ten rooms in the house, he can claim 20%. TurboTax will help you claim this on the page attached. You will just need to enter in the total amount you've paid for these home expenses.