You may not use section 179 to make improvements to your building*. Section 179 is only for the cost of personal property items you purchase for use inside rental units—for example, kitchen appliances, carpets, drapes, or blinds.
But you may deduct building improvements as "repairs" since the amount is less than $2500. If the amount had been more than $2500, you could still deduct it if you got separate invoices for the gutters and the installation and each was less than $2500.
*Reference: https://www.nolo.com/legal-encyclopedia/section-179-expensing-rental-property-owners-deduct-long-ter...
