entering business use of home expenses for shared workspace

I use a room at home for office space (self employed).  The room is not exclusively used for work.  It is used 1 hour/24hr day if I average the hours worked in that room over a year. 

According to the CRA if the room is used exclusively for business, then eligible expenses are based on  (area of room/total home area = 1/10 in my case). 

However if the room is a shared space, the CRA says you have to calculate the number of hours/week the room is used for business purposes  ( in my case:  1/24).   

So the eligible business related expenses are:  (1/10) x (1/24) x expenses.

Question: I have TurboTax Basic and it assumes that the room is exclusively used for business (input only room area/home area).   There is no input for shared space situations where the time that the room is used for business (in my case 1/24) is factored into the calculation. 

 

Am I missing something here?