Chicago · 2 to 4 unit buildings
Both are great first buildings. The difference is one more rent check, and what that check does to your monthly payment.
A quick translation first. A 2-flat is one building with two full apartments, one on top of the other. A 3-flat has three. Most of the country calls the two unit kind a duplex. Chicago built both by the thousands, often on the same blocks. You buy either one the same way: live in one apartment and rent out the rest.
With a 2-flat, one tenant helps pay your mortgage. With a 3-flat, two do. On the same street, the 3-flat usually leaves you paying a smaller share of the bill, and in the right building your share gets close to zero. There is a second quiet win: when one apartment sits empty between tenants, the other one keeps paying. A 3-flat never goes all the way quiet.
A 3-flat costs more than a 2-flat on the same block. But look at the price per apartment and the 3-flat is often the better buy. You are spreading one lot, one roof, and one tax bill across three apartments instead of two.
Here is the part nobody explains. The same loan covers both. Live in the building and a regular loan goes down to 5% on buildings with up to four apartments, and rent from the other units can count toward what you qualify for. FHA's 3.5% loan works on a 2-flat, but on 3 and 4 unit buildings FHA adds an extra math test most buildings do not pass. So 3-flat buyers mostly use the 5% loan. Plan on 5% either way, and the loan stops making this decision for you.
Some buildings sold as 3-flats are legally 2-flats with an extra basement apartment. The city keeps the answer on file. A paper called a Certificate of Zoning Compliance states the legal unit count, costs $120, and is part of selling a small building in Chicago. We pull the zoning on every 3-flat before our buyers fall in love with one. It takes minutes, and it means you buy the building you think you are buying.
Two tenants instead of one means one more lease to sign and one more person whose sink can leak. It is a little more of the job, not a second job. Most owners say the first year teaches them the whole thing either way.
Go where your budget and the block agree. If 2-flat numbers feel tight in the neighborhood you love, a 3-flat on the same street often fixes the math, because the third rent does the heavy lifting. If you want the simplest version of owning, the 2-flat is it, and it is still a building that helps pay for itself.
The good news is you do not have to decide from your couch. Reach out and we will run real buildings of both kinds with you, so you can see the difference in dollars instead of theory. You do not need to know exactly what you want yet. Most people who reach out don't.