Depreciation

Enter the improvement as a separate asset. 

TurboTax may give you the option to expense the improvements, but if you want to depreciate them, 

Click Edit for the rental

scroll down to Assets/Depreciation

Select to go to summary

Click on "Add an Asset" 

New bathroom, floors, carpeting, some windows. I would like to depreciate this over 4-5 years. How do I do this?

You must enter your property improvements in the Assets/Depreciation section. Now I have no doubt that the new windows become a permanent part of the structure. So you would need to classify that as residential rental real estate and depreciate over 27.5 years.

As for the bathroom, I can't see that being classified anything other than residential rental real estate and also depreciated over 27.5 years. It just depends on what you're calling "new" in the bathroom. If it was gutted, then it's cost is depreciated over 27.5 years.

For the "floors", it would depend on what it is. Ceramic tile would be 27.5 years also, as it becomes a permanent part of the structure without question once the thin set dries. If wood floors of a type that lays over an existing floor (floating floor is but one example) that could be classified as 5 year property, even if you took up an old linoleum floor or the old type asphalt tiles for example, before laying the wood.

New carpet is also 5 year property.

I'm of the mindset to keep my depreciation each year as low as I legally can. But that's me.