We have those kinds of deductions in Sweden too. The company that upgrades your home files for the money of your deduction with the IRS and then reduces your bill by the corresponding amount.
If you do the renovations yourself you have to file for the deduction yourself, so there are certainly many situations where you can’t just have every single part of the tax forms automatically calculated. But typically it’s just a matter of logging in to the IRS website and providing the facts as you know them (“I bought stock for X and sold it for Y”) then the system calculates the rest for you.