I have a farm business with a barn & house. How much of my utilities do i enter under farming expenses and how much under business-use-of-home expenses?

For example, if i have $1000 in office expenses, do i enter $1000 in the farming expenses section and again under business-use-of-home expenses (where it's calculated by area)?
And for example, $2000 in electicity expenses - i enter the total $2000 under business-use-of-home and it calculates.  Do i enter $2000 in electricity under farming expenses as well?