Investors & landlords

So looking at my depreciation schedule this is what my high school (pre-Reagan) accounting brain sees--I have multiple assets to carry over (house+handful of improvements over the years); I need to line item them all since they were done at separate times; I need to subtract the amount already depreciated from the depreciation basis and input those amount then depreciate them for whatever period of time remains from their inception as an asset. Does this sound correct to you? Also do you have any idea whether TT will allow me to change the depreciation time remaining manually or whether I'm going to have to line item them anew every year going forward?