House Hacker's Guide to Chicago 3-Flats

This walkthrough uses Chicago as an example market — the same math and workflow apply anywhere Prop-Folio operates. See how it works in your market →

Why Chicago 3-flats

Chicago's housing stock is full of 2–4 unit buildings — the result of a century of dense neighborhood construction. A house hack on a 3-flat lets you live in one unit and use the other two units' rents to cover most or all of your mortgage. Owner-occupied financing means FHA or conventional 3.5–5% down instead of investor 20–25% down — the cheapest entry into real estate investing available.

The two loan products that matter

FHA 203(b)

3.5% down on 1–4 unit owner-occupied properties
2026 Cook County loan limit (4-unit): ~$2.2M — well above any realistic Chicago 3-flat price
Self-sufficiency test on 3-4 unit properties: net rental income (75% of gross from other units) must cover the full PITI
You can use 75% of projected market rent on the units you don't occupy to qualify

Conventional (Fannie/Freddie) owner-occupied

5% down on 1-unit, 15% down on 2-4 unit (Fannie's recent change brought 2-4 unit down from 25%)
No self-sufficiency test
Better rate than FHA in most scenarios if your credit is 740+
No mortgage insurance once you hit 20% equity (vs FHA MIP for the life of the loan)

How to underwrite a Chicago 3-flat house hack

Step 1: Pick the strategy in Prop-Folio

Choose Buy & Hold. House hacking is a Buy & Hold with an owner-occupied financing structure — same math, lower down.

Step 2: Configure the loan

FHA: 3.5% down, current FHA rate, 30-year. Conventional: 15% down, conventional rate, 30-year. Both will include PMI or MIP — add to your monthly carry.

Step 3: Configure the income

Two paying units, not three. You live in one. The other two pay the rent that RentCast comps suggest. Use the per-unit rent feature — Prop-Folio handles this natively.

Step 4: Configure operating expenses

Same OPEX stack as any 3-flat: property tax (Cook County 2.0–2.5% of assessed value annually), insurance, vacancy reserve (lower since you're on-site to fill quickly), repairs & maintenance, CapEx. Skip property management since you're managing yourself.

Step 5: Read the cash flow

The key number is monthly cash flow with you living in one unit. If rents from the other two units cover the full PITI plus OPEX, you're living free. If they cover PITI + OPEX + $500/month, you're getting paid to live there.

What a typical Chicago 3-flat house hack looks like

Purchase price: $480,000 (mid-tier Chicago 3-flat)
5% down conventional: $24,000 + ~$8,000 closing = $32,000 cash in
Mortgage + tax + insurance + PMI: ~$3,650/mo PITI
Two rented units at $1,800 each: $3,600/mo gross
OPEX (vacancy/repairs/CapEx): ~$540/mo
Your net out-of-pocket monthly: $590/mo to live in a 2-bed in Chicago — versus ~$2,200/mo rent for a comparable unit on the open market
Effective monthly savings: ~$1,600/mo, before equity buildup

Risks to underwrite

Vacancy: when one of two paying units turns over, you're carrying 50% of the building yourself for 1–2 months. Budget for it.
Maintenance calls: you're 25 feet from your tenants. Set boundaries.
FHA self-sufficiency test failure: if Chicago rents don't underwrite tightly enough, FHA will reject the loan. Switch to conventional.
Move-out plan: after 12 months, you can move out and convert all 3 units to investment use. Plan now what your refinance or sale strategy looks like.

Run your house hack numbers →