More doors, more of everything
Owning a duplex sounds like twice the rent for one roof. And it can be. But it's also two sets of tenants, two move-outs, two sets of repair calls and one shared wall that carries every sound and every leak from one side to the other.
A fourplex or a small apartment building multiplies that again. The work isn't harder than a single-family rental. There's just more of it, and it tends to overlap.
This guide walks through what running a small multifamily property in Boise, Meridian, Nampa or anywhere else in the Treasure Valley actually looks like, and how to decide whether to do it yourself or bring in help. If you want the short version on our side of it, our apartment and multifamily management page covers what we handle.
What's different about a duplex or fourplex
A lot of landlords come to multifamily from a single rental house. Most of what you learned carries over. A few things change.
Your units share systems
Many small buildings share a roof, a water heater, a sewer line or a single water meter. When the main line backs up, it's everyone's problem at once. When the roof leaks, it might show up in the downstairs unit first.
That means your maintenance plan matters more. A slow drip in one unit can become drywall and flooring damage in the one below it.
Your tenants live with each other
In a house, a tenant's habits mostly affect your property. In a duplex, they also affect the neighbor on the other side of the wall. Noise, parking, shared yards, trash cans and pets can all turn into complaints you have to sort out.
Clear lease rules help a lot here. So does screening every applicant with the same written criteria, so you're picking people who'll be good neighbors as well as good payers.
Turnovers stack up
With four units, you might have a move-out every few months. Each one means an inspection, a deposit accounting, cleaning, repairs, new photos, a new listing and a round of showings. If two units come open at the same time, it gets busy fast.
Utilities need a plan
Some buildings have separate meters for everything. Others share water, sewer or trash. If you're paying a shared bill, decide up front whether you'll build it into rent or bill it back, and write it into the lease so nobody's surprised.
The core jobs, unit by unit
Whether you have two doors or twelve, the jobs are the same. Here's what has to happen to keep a small building running well.
- Setting rent. Each unit should be priced against what similar units are renting for right now, not what you charged two years ago. Units in the same building can differ in size, layout, view and condition, so they don't always rent for the same amount. Our free rent estimate is a good place to start.
- Marketing and filling vacancies. Good photos, a clear listing, quick replies and easy showings. We go deeper in how to fill a vacant rental fast.
- Screening. Same written standard for every applicant: credit, income, rental history, background and eviction history. Our guide on how to screen tenants lays it out.
- Leases. A solid lease with house rules that fit shared living: quiet hours, parking, shared spaces, trash, pets and who handles snow and yard care.
- Collecting rent. Online payments, a clear due date, a consistent late policy and follow-up the same day rent is late.
- Repairs and maintenance. Fast response on repair requests, plus routine checks on the systems that serve more than one unit.
- Move-outs. Inspections, photos and deposit accounting done on time and in writing.
- Books and records. Income and expenses by unit, so you can see which units are pulling their weight and have clean numbers at tax time.
Idaho rules that come up often in small buildings
Idaho's landlord-tenant law applies the same way whether you own one rental or a building full of them. A few pieces come up constantly in multifamily.
- Security deposits. Under Idaho Code 6-321, you have 21 days to return a deposit, or up to 30 days if your lease says so. Anything you keep needs a signed, itemized statement, and you can't charge for normal wear and tear. With more units, more move-outs, more deadlines.
- Month-to-month tenants. Ending a month-to-month tenancy takes written notice of at least one month under Idaho Code 55-208.
- Rent increases. You can't raise rent in the middle of a fixed-term lease, and a month-to-month tenant needs written notice at least 30 days before an increase takes effect.
- Smoke detectors. Idaho Code 6-320 requires working smoke detectors in each dwelling unit at the start of a rental agreement. Every unit, not just the building.
- Late rent. The eviction process starts with a written three-day notice under Idaho Code 6-303. A landlord can't change the locks or shut off utilities to force someone out.
Boise has a few extra rules
If your building is inside Boise city limits, the city adds some of its own rules, summarized on its tenant rights and responsibilities page.
A couple matter for small-building owners in particular. The city lists an ordinance against retaliating against tenants who ask for repairs. And under Boise's housing code, a repair needed to fix a code violation has to be made within three business days.
Statewide, any fee you charge a tenant has to be reasonable and written into the lease (Idaho Code 55-305). And since 2025, Idaho Code 55-306 bars cities from regulating rent, fees or deposits, so some older local rules on fees may no longer apply. Check with the city if you're unsure.
This isn't legal advice, and laws change. When something's high stakes, like an eviction, talk to an Idaho attorney.
Maintenance is where small buildings win or lose
Ask a few multifamily owners what keeps them up at night and you'll hear the same answer. It's not vacancy. It's the repair that turned into three repairs because nobody caught it early.
A few habits go a long way:
- Make it easy to report problems. Tenants will tell you about a small leak if it's easy. If it's a hassle, they'll wait until it's a big one.
- Check shared systems on a schedule. Water heaters, HVAC, roof, gutters and sewer lines. Filter changes and a look at the roof before winter cost very little compared with a ceiling repair.
- Respond fast, even when the fix takes longer. A quick reply and a scheduled visit keeps a tenant calm. Silence makes them start looking at other rentals.
- Fix it properly. Patching the same problem three times is more expensive than fixing it once.
This is a big part of why owners hire us. Cory, our owner, is a licensed contractor with more than ten years of experience and also an HVAC tech. Repairs are handled in-house by our own team, so there's no outside vendor markup and no waiting on someone else's schedule.
Should you self-manage or hire a property manager?
Plenty of people manage a duplex themselves, especially if they live in one side. It's very doable when you're nearby, handy and have some time.
It gets harder as the unit count goes up, or when life gets busy. Here are a few honest signs you've outgrown doing it yourself:
- You're spending evenings and weekends on showings, texts and repair calls.
- Repairs are waiting because you can't get a contractor out.
- Units are sitting empty longer than they should.
- You don't live close to the building anymore.
- You're not sure your lease, deposit handling or notices would hold up if a dispute came up.
If a couple of those sound familiar, it's worth getting a quote. Our guide on choosing a property management company in the Treasure Valley covers what to look for and what to ask.
If you live in one unit and rent out the other, read is house hacking a duplex worth it before you decide either way.
How Badger handles duplexes and small apartment buildings
We're a family-owned property management company based in Nampa, and small multifamily is a big part of what we do. We don't manage commercial property. We focus on homes, duplexes, fourplexes and small apartment buildings across Boise, Meridian, Nampa, Eagle, Star, Caldwell, Kuna and Middleton.
Here's what that looks like for an owner:
- Filling units. We list on more than 14 rental platforms and screen every applicant with a point-based system that looks at credit, income, rental history, background and eviction history. More on that on our tenant placement page.
- In-house repairs. Our licensed contractor team handles maintenance directly, with no vendor markup.
- Renter's insurance required. Every tenant carries it, which matters more when one unit's accident can affect another.
- Owner portal. You can see what's happening with your property and your money without having to call.
- Straightforward terms. No long-term contracts, no hidden fees and no renewal fees.
We own rental property ourselves, so we manage yours the way we'd want ours managed. Pricing depends on the property, so we don't post a one-size rate. Tell us about your building and we'll walk you through it, or see our apartment management page for the details.
The takeaway
A duplex or small apartment building is a single rental with the volume turned up. Price each unit right, screen everyone the same way, stay ahead of shared-system repairs and keep your paperwork clean.
Do that and small multifamily can be one of the steadier investments around. If the volume is more than you want to carry, that's exactly the part a good local manager takes off your plate.
