Ordinance or law coverage pays the extra costs that building codes add to a repair after a covered loss. Your policy will rebuild what you had — this coverage handles the gap between what you had and what today's codes require you to build instead.
Who this is for: owners of older homes especially, but really anyone in a town that has updated its building codes since their house went up. Which is nearly everyone.
The gap it fills
Homeowners insurance is built to restore your home to its pre-loss condition. But cities don't let you rebuild to 1975 standards. After a fire or major storm damage, the permit office may require modern wiring, updated plumbing, current energy and safety standards, or new foundation work — none of which existed in the home before the loss. A standard policy can decline to pay for those upgrades, because they're improvements, not repairs. Ordinance or law coverage exists to pay for exactly that.
The three pieces
The coverage typically has three parts, and it's worth knowing all of them.
Loss to the undamaged portion. Many local ordinances say that if a building is damaged past a certain threshold — often around half — the whole structure must come down. Without this coverage, insurance pays for the damaged part only; you'd eat the value of the intact half being demolished.
Demolition cost. Tearing down that undamaged portion and hauling away the debris isn't free. This piece pays for it.
Increased cost of construction. The code-upgrade piece: rebuilding with the wiring, plumbing, and structural requirements your municipality enforces now.
How much comes built in
Many standard policies include a modest amount of ordinance or law coverage automatically — often around 10% of your dwelling limit. For a newer home that may be plenty. For a home with knob-and-tube wiring, galvanized pipes, or an unreinforced foundation, the required upgrades after a serious loss can cost far more than that built-in cushion. Insurers sell higher percentages as an endorsement, and the price is usually reasonable relative to the gap it closes.
What it doesn't cover
It only responds after a covered loss. If the city requires you to update your electrical panel just because it's old, that's a maintenance cost, not a claim. It also doesn't cover code upgrades tied to excluded perils like flood, and pre-existing code violations you were already required to fix are out.
The older-home angle
If you own an older home, this coverage and your policy form are two sides of the same question. Homes that are hard to insure on standard forms sometimes end up on an HO-8 policy built for older homes, which handles the rebuild-cost problem differently. Either way, asking "what happens if the code office gets involved after a loss?" is one of the smartest questions an older-home owner can put to an insurer.
Carriers treat ordinance coverage very differently, so comparing a few quotes is a quick way to see who builds in more from the start.