Renting out a duplex means running it as a small business. To rent out a duplex legally, you need a local rental license, a landlord insurance policy in place of your homeowners policy on the rented side, a lease that spells out who handles shared maintenance, a screening process that follows federal fair housing and credit reporting law, and a tax plan that splits expenses between the personal and rental portions of the building. The steps below walk through each piece in the order you’ll hit them.
Get Licensed and Make the Unit Safe
Most cities require a rental license or certificate of occupancy before you can legally collect rent. The process usually involves scheduling an inspection that confirms each unit meets local safety and habitability standards. Fees and renewal cycles vary by jurisdiction, so check with your local building or housing department before you list. Operating without the required license can result in fines, an order to stop collecting rent, or both.
Safety basics apply to every unit. Smoke alarms must be installed inside every bedroom, outside each sleeping area, and on every level of the unit, including the basement.1National Fire Protection Association. Installing and Maintaining Smoke Alarms Interconnected alarms that all sound when one is triggered provide the best protection, because a closed bedroom door can delay smoke from reaching a sleeping tenant.2USFA.FEMA.gov. Smoke Alarms Carbon monoxide detectors are required in the immediate vicinity of each bedroom whenever the unit has a fuel-burning appliance, a fuel-burning fireplace, or sits above or below an attached garage without adequate ventilation.3U.S. Department of Housing and Urban Development. NSPIRE Standard – Carbon Monoxide Alarm
Each unit needs working heat, functional plumbing, and a structurally sound living space to meet baseline habitability standards. Municipalities enforce these through code violations that carry fines and, in serious cases, court orders barring rent collection until repairs are complete. Keep a fire extinguisher rated for ordinary combustibles, flammable liquids, and electrical fires in the kitchen or a shared hallway. Fixing these items before a tenant moves in is cheaper than fixing them under regulatory pressure.
Switch Your Insurance Before the First Rent Check
A standard homeowners policy covers an owner-occupied home. The moment you start collecting rent on a unit, that policy likely stops covering the rental side. Claims filed under the wrong policy get denied, and you find out at the worst possible time. If you live in one unit and rent the other, you generally need a landlord policy (often called a DP-3) on the rented unit and a homeowners policy on the unit you occupy. Some insurers offer a single policy tailored to owner-occupied duplexes.
Landlord coverage differs from homeowners coverage in a couple of ways worth knowing. Loss-of-use coverage on a homeowners policy pays for your temporary housing if your unit becomes uninhabitable. The landlord equivalent, called fair rental income coverage, reimburses you for lost rent when a covered event makes the rental unit unlivable. Landlord policies do not cover a tenant’s personal belongings. Require renters insurance in the lease so tenants have their own coverage and your liability exposure drops.
Handle Lead Paint Rules if the Building Predates 1978
If your duplex was built before 1978, federal law requires specific disclosures before any lease is signed. You must give the prospective tenant a copy of the EPA pamphlet “Protect Your Family from Lead in Your Home,” disclose everything you know about lead-based paint in the unit or common areas, hand over any existing testing reports, and include a lead warning statement in the lease.4U.S. Environmental Protection Agency (EPA) and U.S. Department of Housing and Urban Development (HUD). Lead-Based Paint Disclosure Rule Fact Sheet Keep a signed copy of these disclosures for at least three years after the lease begins.
The disclosure rule does not require you to test for or remove lead paint. But if you do any renovation, repair, or painting work that disturbs more than a small amount of painted surface in a pre-1978 unit, the EPA’s Renovation, Repair, and Painting (RRP) Rule applies. A landlord who personally handles the work must hold both firm and renovator certification. Hiring an outside contractor shifts the certification burden to that firm, but the contractor must still be a Lead-Safe Certified Firm using a certified renovator on site.5US EPA. Lead Renovation, Repair and Painting (RRP) Rule Compliance for Landlords Civil penalties per violation are steep enough that one renovation gone wrong can wipe out a year of rental income.
Set Rent, Deposits, and Shared Utilities
Pricing the Unit
Price by comparing to similar duplexes within a few miles, not single-family homes or large apartment complexes. Square footage, bedroom count, parking, in-unit laundry, and whether utilities are included all shift what tenants will pay. Setting rent slightly above your mortgage-and-maintenance break-even is the baseline, but overpricing leads to vacancies that cost more than a modest rent reduction would have.
Shared Utilities
Duplexes often share a water, gas, or electric meter. Separate meters are the simplest arrangement, since each tenant pays their own bills. When meters are shared, you have two main options. Fold the utility cost into the rent, which simplifies billing but removes any incentive for tenants to conserve. Or use a ratio utility billing system (RUBS), where you allocate the master-metered bill using a formula based on square footage, number of bedrooms, or number of occupants. RUBS is legal in most places, but some jurisdictions regulate the allocation method or cap the administrative fees you can pass through. Check local rules before setting one up.
Security Deposits and Late Fees
Security deposits protect you against unpaid rent and damage beyond normal wear and tear. The maximum you can collect varies significantly by state. Some cap deposits at one month’s rent, others allow two or three months, and a handful impose no statutory limit. In states that cap, the limit sometimes changes based on whether the unit is furnished. Collecting more than the legal maximum exposes you to penalties, which in some states include a requirement that you return the entire deposit plus damages.
Late fees need to be legally enforceable. Most states require them to be “reasonable,” and some cap them at a specific percentage of rent or a flat dollar amount. The common range among states that set limits runs from about 4 to 10 percent of monthly rent. Courts in states without a statutory cap can still strike down fees that look punitive rather than compensatory. Spell out the fee amount, the grace period, and the trigger date in the lease.
Write a Lease That Covers Shared-Building Issues
A solid lease prevents most disputes. Standardized forms from local real estate boards or legal document providers cover the basics, but duplex-specific provisions need customization. Every adult occupant should be named on the lease, and the unit address must include the unit letter or number to distinguish it from the other half of the building.
Maintenance responsibilities need clear assignment. In a duplex, questions like who mows the lawn, shovels the walkway, or maintains a shared porch come up constantly. If the lease is silent, both tenants assume the other is responsible and nothing gets done. Spell out which tasks belong to the tenant, which belong to you, and how common-area upkeep is divided.
Pets and Assistance Animals
If you allow pets, the lease should state any weight limits or breed restrictions along with the pet deposit or monthly pet rent. Assistance animals are a separate category. Under federal law, they are not pets. A tenant with a disability who needs a service animal or an emotional support animal is entitled to a reasonable accommodation, and you cannot charge a pet fee, pet deposit, or pet rent for that animal.6U.S. Department of Housing and Urban Development. Fact Sheet on HUD’s Assistance Animals Notice This applies even if your lease says “no pets.” Denying a legitimate assistance animal request is a Fair Housing violation.
Eviction Notice if You Have a Federally Backed Mortgage
If your duplex has a federally backed mortgage loan, the CARES Act requires at least 30 days’ notice before you can require a tenant to vacate for nonpayment of rent.7Federal Register. Rescinding 30-Day Notification Requirements Related to Eviction Based on Nonpayment of Rent in Multi-Family Housing Direct Properties FHA, Fannie Mae, Freddie Mac, VA, and USDA loans all count. Many states impose longer notice periods on top of that federal floor. Serving a notice that’s too short can void the entire eviction proceeding, so confirm your loan type before filing.
Screen Tenants Without Breaking Fair Housing or FCRA
The Fair Housing Act makes it illegal to refuse to rent, set different terms, or otherwise discriminate because of race, color, religion, sex, familial status, national origin, or disability.8Office of the Law Revision Counsel. 42 U.S. Code 3604 – Discrimination in the Sale or Rental of Housing That covers advertising, showing the unit, evaluating applications, and setting lease terms. Write down your screening criteria before the first application arrives, and apply those criteria identically to every applicant.
Common benchmarks include a minimum credit score (620 is a typical threshold), a gross monthly income of at least three times the rent, and a clean eviction history. Before pulling a credit report or background check, get the applicant’s written authorization. The Fair Credit Reporting Act treats these as consumer reports, and using them without proper disclosure and consent is a federal violation.9Federal Trade Commission. Using Consumer Reports: What Landlords Need to Know Verify income with current and former employers, and ask previous landlords about payment history and how the tenant treated the property.
If you deny an application based even partly on information from a credit report or background check, federal law requires you to send the applicant an adverse action notice identifying the consumer reporting agency, explaining that the agency did not make the decision, and informing the applicant of their right to get a free copy of the report within 60 days and dispute inaccuracies.10Office of the Law Revision Counsel. 15 U.S. Code 1681m – Requirements on Users of Consumer Reports If a credit score factored into the rejection, the notice must also include the score, a description of the scoring model, and the key factors that hurt the score. Document every step. Consistent criteria applied uniformly is your best protection against a discrimination claim.
Move the Tenant In With Documentation
Once you’ve picked a tenant, both parties should walk through the unit together using a detailed checklist. Note every scuff, stain, and appliance condition. Take timestamped photos. This record is what you compare against at move-out when you decide whether damage exceeds normal wear and tear. Deposit disputes almost always come down to the quality of your move-in documentation.
Collect the first month’s rent and the full security deposit before handing over keys. Certified funds like a cashier’s check or money order for the initial payment eliminate the risk of a bounced check on day one. Once the lease is signed and funds have cleared, hand over the keys and any access codes.
Report Rental Income and Take Your Deductions
Rental income from the leased unit gets reported on Schedule E of your federal tax return. If you live in one side and rent the other, split deductible expenses between the personal and rental portions of the building. The IRS instructs you to allocate based on usage, and for a duplex with equally sized units, a 50/50 split is the straightforward approach.11Internal Revenue Service. 2025 Instructions for Schedule E (Form 1040) If the units differ in size, allocate by square footage. Expenses that apply only to the rental unit, like a repair inside that unit, are fully deductible against rental income without any allocation.
Depreciation
The rental portion of the building (not the land) is depreciated over 27.5 years using the straight-line method.12Office of the Law Revision Counsel. 26 U.S. Code 168 – Accelerated Cost Recovery System The IRS uses a mid-month convention, meaning property placed in service during a given month is treated as if it started at the midpoint of that month.13Internal Revenue Service. Publication 527, Residential Rental Property For an owner-occupied duplex, only the rental unit’s share of the building value qualifies. Depreciation is not optional. The IRS will recapture it when you sell the property whether or not you claimed it, so there is no advantage to skipping it.
Qualified Business Income Deduction
Rental property owners may qualify for a deduction of up to 20 percent of their qualified business income under Section 199A. This deduction, originally set to expire at the end of 2025, has been permanently extended.14Internal Revenue Service. Qualified Business Income Deduction To qualify, the rental activity generally needs to rise to the level of a trade or business, though the IRS provides a safe harbor for rental real estate enterprises that meet certain record-keeping and hour requirements. A duplex with active management responsibilities often clears that bar, but a tax professional can confirm whether your specific situation qualifies.