As a CPA I can tell you that you need a complete financial plan. You can deduct only remodeling expenses that are directly related to making the house accessible (or adaptable for other medical reasons) and only to the extent that it does not improve the value of your house. For example, I spent around $50,000 making my house accessible by widening doors, putting grab bars around, completely gutting and renovating a perfectly good bathroom to make it wheelchair accessible, replacing all lights with LED, just to name a few things. I got an appraisal before the improvements and will get one after the improvements. Let's say my condo goes up in value by $20,000 and I spent $50,000. I can deduct the $30,000 as medical expenses but that will be reduced by 10% of my adjusted gross income. You can also deduct things like conversions on vehicles, ramps, lifts, and any other medical expense. Make sure you get a doctor's Rx to back up your expenditures. Also, get your doctor to write out an Rx for supplements you take and they are deductible as well if your doctor says they are medically necessary. Keep track of your mileage and hotel stays for medical purposes. It all adds up.
You cannot deduct improvements not connected with a medical expense. If you converted the basement to an apartment, that would not be deductible. Everything changes if you rent it out and claim the income from the rent.
This is just a very small piece of a comprehensive financial plan.
What does happen is that it increases the tax basis of your home which might come into play if and when it is eventually sold.