I still own the commercial building.
clarify that statement. If your business was a partnership, multi-member LLC that filed IRS Form 1065 tax returns, or a corporation that filed 1120 or 1120-S tax returns and your business was listed as the owner of the property on the property deed, then the business is not "closed" per-se. The business still owns assets that continue to incur expenses, even if the income producing side of the business has ceased operation.
As far as the IRS is concerned a business is not closed until it has disposed of all inventory, assets, and any vehicles used in the business. So if the building is owned by the business it is an asset that needs to be disposed of by some means before the business is considered closed and before a "final" business tax return can be filed.
The cost of maintaining that building (such as utilities) continue to be claimed as a business expenses, even though there's no business income to offset those expenses. They will be offset in the tax year of the sale by any gain realized on the sale - thus reducing the taxable gain if the building is sold at a gain. So your 2019 maintenance expenses are generally referred to as "carrying cost", which is the cost of maintaining the asset until it is sold. Those carrying costs will reduce your taxable gain on the sale, by increasing your cost basis in the asset.
