Grandfathering

What it is

Grandfathering means: if something was installed in 1975 correctly to code, but now it’s 2025 and the codes have changed, you can grandfather in those old codes. If something is outright dangerous or wrong, obviously you have to fix it. But if it’s there, it was built right in the first place, and you’re not touching it — it’s allowed to stay.

The flip side is where flippers get burned. Once you expose a wall, then you need to follow brand new codes. If you’re adding new walls, it opens up a lot of cans of worms. You touch the electrical there, you’ve had to touch it somewhere else, and then maybe you need to go fix that. The grandfathering protection evaporates the second the sawzall hits the drywall.

That’s why on a cosmetic renovation, there’s no drywall demo, no insulation line, no rewire. The walls stay up. On a gut flip where you’re replacing all the big systems — mechanical, electrical, plumbing, structural — that’s when the drywall comes down, because you’re already in current-code territory and you have to do it all right anyway.

Why it matters

Grandfathering is the single biggest lever for keeping a flip budget under control. Most profitable flips are cosmetic flips, and the defining feature of a cosmetic flip is: the drywall stays up. Paint it, skim-coat it, fix a few holes, but leave the walls closed. As long as the walls are closed and you’re not pulling MEP permits for new circuits, new supply lines, or new equipment, the house lives under the code that was in effect when it was built. That protection disappears the second a contractor opens a wall unnecessarily.

This is why I teach “don’t take down the drywall unless you have to” as a hard rule. new builder itis is the disease of wanting to tear everything out because it’s easier than working around the existing conditions. Every opened wall is a permit, an inspection, a rewire, a reinsulation, a reframe, and a timeline extension. And none of that invisible work gets paid back at resale because the buyer can’t see it.

The second-order benefit: grandfathering protects your timeline. Permitted work has inspection queues, re-inspection failures, and inspector schedules you don’t control. Cosmetic work has none of that.

How it shows up

Framing modification is a good example. If you’re trying to add walls to change the layout, you open up that can of worms and new things start coming up. You have to bring electrical into the new wall. But once you’ve touched the electrical there, you’ve had to touch it somewhere else. One change pulls the next. That’s the reason I try to avoid framing modifications like the plague — and when I do need them, they go in the extras bucket in the Fliporithm because they’re not standard.

Write scope of work that says “do not remove drywall without written approval.” Price demo by the linear foot, not by the room, so contractors don’t over-demo for convenience. If a contractor thinks it’ll be easier to open a wall, pay them the extra hour to work around it. Cheaper every time.

Related

new builder itis, code enforcement, permitting, demo, cosmetic renovation, framing