Lake House STR Owner Gets $91K First-Year Deduction via Cost Segregation

The Problem

This client purchased a $750,000 lake house in eastern Tennessee and operated it as a short-term rental through Airbnb and VRBO. The property generated $78,000 in gross rental income with $31,000 in operating expenses, producing $47,000 in net rental income before depreciation. The client's prior CPA was depreciating the entire building over the standard 39-year recovery period (treating it as commercial property due to average rental periods under 7 days), resulting in just $16,300 per year in depreciation — far below what a cost segregation study could produce.

The client had $410,000 in W-2 income from a corporate management position and was looking for ways to offset that active income. However, rental activity is generally passive under IRC §469, and passive losses cannot offset active W-2 income unless the taxpayer qualifies as a real estate professional or the rental activity meets the short-term rental exception under Treas. Reg. §1.469-1T(e)(3)(ii). The client was unaware that STR properties with average rental periods of 7 days or less are not treated as rental activities for passive loss purposes, meaning losses could potentially offset W-2 income if material participation was established.

AE Tax Strategy

1. Cost Segregation Study Under IRC §168

We commissioned a cost segregation study that identified $262,000 (34.9% of the depreciable basis after land allocation) in components eligible for reclassification into shorter recovery periods. The breakdown: $127,000 in 5-year property (appliances, carpeting, decorative lighting, window treatments, cabinetry), $58,000 in 7-year property (furniture, specialty fixtures, outdoor recreational equipment), and $77,000 in 15-year property (landscaping, fencing, driveway, outdoor lighting, patio hardscaping). Under 100% bonus depreciation (available for assets with recovery periods of 20 years or less placed in service before January 1, 2027, under the One, Big, Beautiful Bill Act), the entire $262,000 was deductible in Year 1.

2. STR Non-Rental Classification Under Treas. Reg. §1.469-1T(e)(3)(ii)

Because the average rental period was 3.8 days (well under the 7-day threshold), the lake house was not treated as a rental activity for passive loss purposes under Treas. Reg. §1.469-1T(e)(3)(ii). This meant the losses could offset active income — but only if the client materially participated in the activity. We analyzed the seven material participation tests under Treas. Reg. §1.469-5T and determined the client met Test 3 (the 100-hour safe harbor), documenting 142 hours of direct involvement including guest communications, property management oversight, maintenance coordination, and furnishing/design decisions.

3. First-Year Deduction Structuring and W-2 Offset

With the $262,000 in bonus depreciation plus $16,300 in standard straight-line depreciation on the remaining building components, total first-year depreciation was $278,300. Against $47,000 in net rental income, this produced a $231,300 net loss. Because the activity was classified as non-rental with material participation established, $231,300 offset the client's W-2 income dollar for dollar. At the client's combined marginal rate of 35% federal plus 0% Tennessee state income tax, the $262,000 in accelerated deductions alone produced approximately $91,000 in first-year tax savings.

Before & After Comparison

Tax Category	Before	After	Savings
Standard Depreciation (39-Year)	$16,300	$0	$16,300
Cost Seg Bonus Depreciation	$0	$262,000	$262,000
Net Loss Applied to W-2 Income	$0	$231,300	$231,300
First-Year Tax Reduction	$0	$91,000	$91,000
Total	$16,300	$278,300	$91,000 (first-year deduction)

Key Takeaways

• Short-term rentals with average rental periods of 7 days or less escape passive activity rental classification under Treas. Reg. §1.469-1T(e)(3)(ii), enabling losses to offset W-2 income with material participation.
• The 100-hour safe harbor under Treas. Reg. §1.469-5T(a)(3) is achievable for most hands-on STR owners — but documentation must be contemporaneous and specific.
• Cost segregation studies on STR properties typically reclassify 30-40% of the depreciable basis into accelerated categories, producing massive first-year deductions when combined with bonus depreciation.
• Land allocation matters — an accurate appraisal separating land from improvements directly affects the depreciable basis available for cost segregation.