ROI verdict · 800 sqft · 5-year hold · mid-range finish
Should I finish my basement as a suite + full bathroom in Illinois?
Our 2026 ROI math for an 800 sqft basement at the mid-range finish tier, anchored to Illinois's median home value ($270,000) and a 5-year hold before sale.
ROI verdict
PROBABLY
Probably worth it
Combined recoup is solid. Go ahead if the personal-use value matches your lifestyle.
Run your exact numbers2026 math (default scenario)
- Project cost (state-adjusted, mid)
- $98,600
- Range
- $61,200 – $136,000
- Resale lift @ year 5
- $52,605
- Personal-use value (5 yrs)
- $36,000
- Total benefit
- $88,605
- Combined recoup
- 90%
Combined return
Defaults: 800 sqft, mid-range finish, 5 years until sale, Illinois median home value ($270,000). Change any input via the live calculator above.
Try a different scope in Illinois
Same state, different use — instant verdict update.
Cost-per-sqft transparency
National baseline for a suite + full bathroom basement finish, before applying Illinois's cost multiplier (×0.85).
- Basic finish (DIY-friendly, builder-grade)
- $90/sqft
- Mid-range finish (most homeowners)
- $145/sqft
- Premium finish (custom millwork, high-end fixtures)
- $200/sqft
- Illinois's state cost multiplier
- ×0.85
- Resale-lift recoup baseline (use-specific)
- 78%
Read next for Illinois
Frequently asked
How much does it cost to finish a basement as a suite + full bathroom in Illinois?
For an 800 sqft basement at our mid-range finish tier, the 2026 state-adjusted cost in Illinois is approximately $98,600 (range $61,200–$136,000). Cost includes labor, materials, permit fees, and a 10% contingency. Illinois is a lower-cost labor market (~15% below national).
Will I recoup the cost at resale?
Our 5-tier verdict for a suite + full bathroom basement in Illinois is PROBABLY. The use-specific NAR Cost-vs-Value recoup baseline is 78%, then time-decayed by years-until-sale (we used 5 years for this estimate — change it with the live calculator). For Illinois's $270,000 median home value, our over-improvement guardrail caps the appraisal lift at the higher of ~$21,600 or 85% of project cost.
What's the verdict logic?
Combined recoup % = (resale lift + personal-use value) ÷ project cost. ≥110% → STRONG YES, ≥85% → PROBABLY, ≥60% → BORDERLINE, ≥40% → PROBABLY NOT, below 40% → DON'T. Personal-use value is $/sqft/yr × sqft × years held (varies by use: rec room $4, suite+bath $9, rental unit $22).
Should I do a different scope instead?
In Illinois, the recoup curve shifts notably by use. Rental-unit conversions recoup 85% (appraiser uses cap-rate underwriting); full-suite-with-bath 78%; bedroom suite 75%; rec room 70%; home office 63%. If you're forever-home + want utility, scope to your lifestyle. If you're <5 years from sale, lean toward a bath addition — it's the single biggest resale-lift item.
Methodology
Cost-per-sqft sourced from the 2026 NAR Remodeling Cost vs Value report, HomeAdvisor 2026 True Cost Guide, and Remodeling Magazine's basement remodel benchmark — includes labor, materials, permit fees, and a 10% contingency. State multipliers from HavenCostGuide's same-base cost index that powers our 550 state landing pages. Resale lift = use-specific recoup × time-decay (100% yr 1 → 5% beyond yr 12), capped by the higher of (85% × project cost) or (8% × home value) — the over-improvement guardrail. Personal-use value = $/sqft/yr × sqft × years held. Verdict thresholds applied to the combined recoup percentage.
For your actual decision, run the live calculator with your exact sqft, finish tier, home value, and years-until-sale. This leaf is a sane default — not a contractor-quote replacement.