A Former Home Becomes a Rental in Stages
Reconstruct the conversion timeline and business-use allocation before calculating depreciation.
About this planning example
Anonymized composite planning example informed by recurring discovery-call themes. Facts are generalized to protect privacy. This is educational analysis, not a testimonial or a report of completed client work, verified savings or investment results.
The situation
An owner first rents one portion of a home while living in the rest, then moves out and makes the entire property available to tenants. Renovations occur between those dates. A proposed cost segregation calculation uses the current market value of the whole property, which may not match the depreciation basis or the amount used for rental purposes during each period.
The decision
There is no single conversion date for every dollar in this fact pattern. The occupied portion, first rental area, later improvements and furnishings may follow different timelines. The planning work starts with a property history rather than a target deduction. It also needs to preserve information for a future sale.
Tax rule to verify
For a personal residence converted to rental use, depreciation basis generally starts with the lower of adjusted basis or fair market value at conversion. Land is not depreciable, and personal and rental use must be separated.
Our recommendation
Create a dated floor plan and use schedule. Reconcile the original closing statement, capital improvements and conversion-date valuation. Allocate land and the rental portion using supportable records, then establish asset schedules for each applicable service date. Have the preparer review personal-use days and the eventual sale implications before projecting a benefit.
Records needed before implementation
- Purchase closing statement and improvement invoices
- Conversion-date valuation and land allocation support
- Floor plans, leases, move-out dates and personal-use calendar
What could change the recommendation
If conversion value is below adjusted cost, an appreciation-based calculation will overstate depreciation. If only one unit is rented, a whole-building deduction is inappropriate. A future move back into the property would require another review rather than simply continuing the same business-use assumptions.
The planning deliverable
A conversion workpaper linking each asset to its basis, rental percentage and service date. No deduction amount is claimed in this illustrative case because those records determine the answer.
Source and further reading
IRS Publication 527: Residential Rental Property
Reviewed October 19, 2026. Apply the rules for the relevant tax year with your preparer; state treatment may differ.
Related Reading
Talk Through Your Situation
Every situation turns on its own facts. Schedule a discovery call and we will walk through what applies to you, what it is worth, and what it would take to put it in place.