House hacking: using real estate to reduce your living costs

House hacking is the practice of buying a property and renting out part of it — a room, a basement unit, or a separate door in a duplex — so the rental income pays a significant portion of your mortgage. Done well, it can reduce your effective housing cost to zero or even negative, building equity while other people's rent covers your loan.

The main variants

• Single-family with a roommate: buy a house, rent a room. Simplest entry, limited income, shared space.
• Single-family with an ADU: buy a house with an accessory dwelling unit (casita, basement apartment, garage conversion). More privacy, more rent, more upfront complexity.
• Duplex, triplex, or fourplex: buy a 2–4 unit property. You live in one unit, rent the others. Qualifies for owner-occupied residential mortgages with low down payments.
• BRRRR method: Buy, Rehab, Rent, Refinance, Repeat. Advanced, requires construction knowledge and capital cycling.

Why it works

Owner-occupied loans have dramatically lower down payments (3.5–5%) than investment property loans (20–25%). By occupying a unit you qualify for the better loan, but the economics work out like owning a rental — rental income offsets most of your housing cost.

What can go wrong

• Bad tenants. A single eviction can cost thousands and destroy your return for the year.
• Vacancy. Rent doesn't come in every month guaranteed — budget for 1 month of vacancy per year.
• Maintenance. You're now a landlord. Toilets leak at 2 AM.
• Privacy. Living with roommates or tenants is an adjustment most people underestimate.

Who it's for

House hacking is best for people with moderate income who want to accelerate wealth-building, have the temperament to be a landlord, and live in markets where the math works. It's especially powerful for people under 35 in expensive cities — the difference between paying rent and being paid rent can add hundreds of thousands to net worth over a decade.

The full duplex math, with the unglamorous lines included

The example above is the brochure version. Here's the operating statement version for the same $400,000 duplex with 5% down at a 6.6% rate — including the lines new landlords forget. The loan is $380,000, and FHA or conventional owner-occupied financing makes it possible with about $20,000 down plus roughly $10,000 in closing costs. Note that vacancy, maintenance, and capital reserves aren't optional; they're just costs that arrive on an irregular schedule.

Honest math shows house hacking rarely means living free in year one — here it costs about $300 more per month than renting a one-bedroom. What you get for that $300: roughly $400 a month of principal paydown from day one, appreciation on a $400,000 asset you controlled with $30,000, rents that rise over time while your P&I doesn't, and the option to move out later and keep the whole property as a rental. Five years in, with 3% annual rent growth and modest appreciation, a typical outcome is $90,000–120,000 of equity from that original $30,000 — a return renting cannot structurally match.

Getting started, step by step

1. 1
   Get pre-approved as an owner-occupant

   Tell lenders you're buying a 2–4 unit property to live in. Conventional now allows 5% down on 2–4 units for owner-occupants; FHA allows 3.5%. Lenders can often count about 75% of the other units' market rent toward your qualifying income.

2. 2
   Learn your market's rent-to-price reality

   Screen deals fast: monthly rent from the units you won't occupy should approach 0.5% or more of the purchase price for the math to work at 2026 rates. Check actual listed rents, not the listing agent's pro forma.

3. 3
   Inspect like a landlord, not a homeowner

   Separate utilities and meters, roof and HVAC age, and code-legal bedrooms and egress determine your operating costs and your rent. An unpermitted basement unit that can't legally be rented is a dealbreaker, not a bonus.

4. 4
   Screen tenants by process, not vibes

   Written criteria, income at 3x rent, credit and eviction checks, prior-landlord calls, and a state-specific lease. Most house-hacking horror stories are actually tenant-screening horror stories.

5. 5
   Live there a year, then decide

   Owner-occupied loans generally require 12 months of occupancy. After that, you can move out, rent your unit, and repeat the process on a second property — the classic slow-motion portfolio.

Financing fine print and first-year expectations

The loan is where house hacking is won. Owner-occupied multifamily financing is a genuine subsidy — but it comes with fine print. Conventional loans on 2–4 unit properties allow 5% down for owner-occupants; FHA allows 3.5% but applies a self-sufficiency test to 3–4 unit buildings, requiring the property's total market rent to cover the full payment, which many properties fail at current prices. Lenders will usually credit about 75% of the other units' market rent toward your qualifying income, which is often the difference between approval and denial.

• Budget the first year honestly: expect at least one turnover or repair surprise in the first twelve months, and treat the reserve lines as bills you pay to a savings account.
• Price insurance correctly — a two-to-four unit owner-occupied policy costs more than a single-family policy, and you should require tenants to carry renters insurance.
• Know your local landlord-tenant law before you list the unit: notice periods, deposit limits, and eviction timelines vary enormously by state and city.
• Set rent from comparable listings, not from your mortgage payment. Tenants pay market rent, not your costs.
• Keep a separate bank account for the property from day one — it simplifies taxes, security deposits, and the moment you scale to property number two.

And remember the exit options: after your occupancy year you can move out and rent both units, sell with an owner-occupant's tax exclusion on your share, or refinance once rents and appreciation push your equity past twenty percent to drop PMI. A property that works under all three exits is a safe buy; one that only works if everything goes right isn't a hack, it's a hope.

The bottom line

House hacking converts your biggest expense into a leveraged investment, at the cost of becoming a part-time landlord with roommates or tenants on the other side of a wall. Run the full operating math including vacancy and reserves, buy only where rents genuinely support the price, and screen tenants like the business this is. Done soberly, it's the most accessible wealth accelerator in real estate; done on brochure math, it's an expensive way to learn plumbing.