Chicago vs Suburban Cook County Cost Segregation: When the Shared Housing Ordinance Matters

Quick answer

Across 5 engine fixtures for the Chicago area, the differences between Suburban Cook County and the rest of Chicago come down to three factors: land allocation, property archetype mix, and HOA capital-assessment patterns. See the per-fixture detail below.

Side-by-side per-fixture

Property	Sub-market	Price	Reclass %	Y1 fed savings @ 37%	Land %
Lincoln Park SFR Flip SFR	Lincoln Park / Bucktown / Wicker Park	$685,000	16.0%	$29,720	26.5%
Logan Square Two-Flat Investor DUPLEX	Logan Square / Avondale	$545,000	17.4%	$26,969	23.2%
Pilsen Three-Flat BRRRR TRIPLEX	Pilsen / Bridgeport (Lower West Side)	$425,000	17.6%	$20,886	24.7%
South Loop Condo Rental CONDO	South Loop / West Loop (downtown-adjacent condo)	$685,000	11.9%	$15,469	48.9%
Oak Park Suburban SFR LTR SFR	Oak Park / Evanston (suburban Cook County)	$485,000	15.8%	$21,886	23.1%

What's the same

• Tax law. Both sub-markets are in Illinois, subject to the same state conformity rules: Illinois generally follows federal MACRS rules but is NOT fully conforming on federal §168(k) bonus depreciation. The Illinois Income Tax Act requires addition modifications for federal bonus depreciation, with subsequent subtraction modifications that recover the deduction over multiple Illinois tax years rather than concentrating it in Year 1. For 2025+ acquisitions under OBBBA's 100% federal bonus, the federal §168(k) acceleration captures cleanly in Year 1, but the Illinois-side benefit is spread across multiple years rather than fully accelerated. Verify current-year Illinois treatment with your CPA; IL bonus depreciation conformity has been adjusted multiple times in recent years and continues to evolve through 2026 legislation.
• Federal §168(k) bonus depreciation. 100% under OBBBA, permanently restored for 2025+ acquisitions.
• MACRS classification methodology. Same Rev. Proc. 87-56 asset class life assignments regardless of sub-market.
• Engine methodology. Same RSMeans 2024 base costs, same BLS PPI time index, same geo factor (these are city-level, not sub-market-level).

What's different

• Land allocation. Suburban Cook County typically runs higher on land allocation because of either resort-tier land scarcity premiums or proximity-to-amenity scarcity. This compresses depreciable basis as a percentage of purchase, even though absolute basis is larger.
• Property archetype mix. Suburban Cook County concentrates in higher-end vacation rental product, while the broader Chicago market includes more off-market SFRs and longer-tail product.
• HOA capital assessment patterns. Resort-tier HOAs in Suburban Cook County often levy special assessments for infrastructure (snowmelt, lift access, parking decks). Those assessments add to depreciable basis but distort the per-fixture cost-seg picture if the buyer doesn't separate base purchase from assessments paid.
• STR economics. Different ADR (average daily rate) profiles and material-participation friction.

Which is better for cost-seg ROI?

It depends on what "better" means.

If you measure ROI as Year-1 federal savings dollars: Suburban Cook County wins on absolute dollars (higher purchase prices = larger absolute deductions). If you measure ROI as savings-per-dollar-of-purchase: the broader Chicago non-resort sub-markets typically win (lower land allocation = more depreciable basis as % of price).

For most buyers, the more useful question is: which sub-market matches my buy-box? If you're already buying $2M+ resort-tier product, the cost-seg differential is a rounding error against your decision drivers. If you're price-shopping across sub-markets and considering both, the broader Chicago non-resort areas produce more reclassification per dollar.

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