windows are a permanent part of the structure and their depreciable life is 27.5 years. they don't qualify for the 179 deduction. 179 is only available for certain improvements to commercial property. your property sounds like it's residential
Qualified section 179 real property. You can elect to treat certain qualified real property you placed in service during the tax year as section 179 property. If this election is made, the term “section 179 property” will include any qualified real property that is:
• Qualified improvement property as described in section 168(e)(6) of the Internal Revenue Code (see below for definition) , and
• Any of the following improvements to nonresidential real property placed in service after the date the non-residential real property was first placed in service.
1. Roofs.
2. Heating, ventilation, and air-conditioning property.
3. Fire protection and alarm systems.
4. Security systems.For more information, see Special rules for qualified sec-tion 179 real property, later.
Qualified improvement property. Generally, this is any improvement to an interior portion of a building that is nonresidential real property if the improvement is placed in service after the date the building was first placed in service.
Also, qualified improvement property does not include the cost of any improvement attributable to the following:
• The enlargement of the building,
• Any elevator or escalator, or
• The internal structural framework of the building.
the door also 27.5 year life. won't qualify for 179 if it's residential property.
from the IRS
Replacements of the entire roof and all the gutters, and all windows and doors of your residential rental property:
Are generally restorations to your building property because they're replacements of major components or substantial structural parts of the building structure. As a result, these replacements are capital improvements to the residential rental property.
Are a separate asset with a new placed-in-service date and are in the same class of property as the residential rental property to which they're attached.
Are generally depreciated over a recovery period of 27.5 years using the straight line method of depreciation and a mid-month convention as residential rental property
