Above is a covered ramp and deck installed between a modular building and a warehouse.
Notice the clear roofing material over the deck and ramp.  It allows light in, but keeps the rain out.

Typically, the cost of an improvement to a business asset is normally treated as a capital expense.  However, you can choose to deduct the costs of making your business facility more accessible to those who are disabled or elderly.  You can deduct your barrier removal costs as a current expense for any one or more of the following areas to be corrected; grading, walkways, parking lots, ramps, entrances, stairs, floors, toilet rooms, water fountains, public telephones, elevators, controls, identification or warning signals.  You are allowed up to $15,000 in deductions for any tax year and any costs over that amount can be added to your property cost and handled with normal depreciation.  You cannot deduct costs incurred to completely renovate or build a facility in the normal course of business, but you can deduct the cost to remove barriers for the disabled and elderly.