It is slightly more complicated, due to the possibility of a recapture amount (income amount that is added to your rental income) or you may be able to claim a terminal loss (loss amount that gets deducted from your rental income).
I'm going to base the following answer on the assumption that you are using Forms mode. (Simply because it would be easier for me to describe what you need to do.) So in Forms mode, please locate the T776 that has all your information regarding this rental property.
On page 3 of the T776 is where you enter all the information regarding CCA. In Area A, you will have a row with information for Class 1 (your building). You would have entered the starting UCC balance for the year in column 2.
In Area E, you will indicate that you disposed of your Class 1 building. Now here is where it gets a bit more complicated. In the Proceeds column, you need to enter the LOWER amount between the Proceeds of the building and the actual cost of the building. So if the sale proceeds on the building was $500K and the original cost of the building was $200K, you will need to enter $200K into the Proceeds column. If the sale proceeds was $100K and the original cost of the building was $300K, you will need to enter $100K into the Proceeds column.
(In your proceeds, you will need to factor in the expenses related to the sale. These costs will need to be apportioned between the land and the building.)
That will take care of the UCC/CCA of the building, and you will likely end up with either a recapture (see line 9947 on the T776) or a terminal loss (see line 9948 on the T776).
Don't forget to report any capital gains or capital loss on the schedule 3.
