is a live-in flip just a normal house purchase with extra steps

The profit comes from buying below what the finished house is worth, and then doing the work that closes that gap. Say a repaired house on the street sells for $300k. You buy the tired one at $210k because it needs a kitchen, a bath and a roof, and you spend $40k on materials doing much of the labor yourself. Your money in is $250k against a $300k house. That $50k is the flip part, and it exists whether or not the market moves at all. Market appreciation sits on top of it and is a separate thing.

Basis is the term for your money in, meaning the purchase price plus what you spend on capital improvements. Gain is sale price minus basis minus selling costs. The primary-residence capital-gains exclusion lets you exclude gain from tax if you owned and lived in the home for at least two of the five years before the sale, up to $250,000 single or $500,000 married filing jointly. It isn't once in a lifetime. It's usable repeatedly, though there's a rule limiting how often, so confirm your own timing with a CPA.

Yes, the line between a live-in flip and someone slowly improving their home is mostly intent and scale. The difference that matters practically is that a live-in flipper picks the house for the spread and does work that adds resale value, while a homeowner improves for their own comfort. Those aren't always the same projects. A soaking tub you love may return nothing on the sale.

The part your friend skipped is that "no rush" and "living there" fight each other. You can't have the only bathroom torn out for six weeks the way you can on a vacant flip. So you sequence around your own life, and sequencing costs money. My scope on a vacant house goes in whatever order is cheapest for the trades. In an occupied house it goes in whatever order keeps a working kitchen and a working shower, which sometimes means paying to do a job twice.

@marlow on the tax question, it's per sale, not per lifetime. The old rule people are remembering was a one-time thing for older sellers and it went away a long time ago. That's why you still hear both versions.

Where I'd push back on the whole premise: your $50k spread only exists if you actually buy at $210k. On a house that a regular family could live in while fixing, you're bidding against regular families, and they'll pay more than you because they're buying a home not a margin. The really discounted stuff is discounted because it's uninhabitable, and you can't live in uninhabitable. That squeeze is the hard part of this strategy and nobody mentions it.

Something practical for the income question you started with: a live-in flip gives you no income for two years. Zero. Your money is in drywall. If what you want is monthly cash coming in, this isn't the strategy, it's a lump sum at the end that happens to be tax favored.

@flint that's the thing I've been circling on my own list. The houses that are both livable and cheap enough to have room in them are almost always livable-but-ugly rather than livable-but-broken. Ugly is cosmetic, cosmetic is cheap to fix, and everyone can see the fix, so it's priced in. The spread hides in things people are scared of, like a failed septic or a foundation crack, and those are exactly the ones you don't want to be sleeping above.