Of all the settings on a landlord policy, this is the one that most directly decides how much of a claim you actually collect, and it is the one owners are least likely to have checked. Replacement cost and actual cash value are not about whether a loss is covered. They are about how much you get paid once it is. On a newer property the difference is modest. On an older roof it can be the difference between rebuilding and writing a large check of your own. Here is how the two work, where the gap bites hardest, and how to find out which one you have.
The core difference
Replacement cost pays what it actually costs to repair or replace the damaged property, using like materials, without subtracting for age. If a covered loss takes out your roof, a replacement cost policy pays to put a new roof on, period.
Actual cash value pays the depreciated value: the replacement cost minus wear and age. The same roof, settled at actual cash value, pays what that aging roof was worth at the moment of the loss, which can be far less than the cost to replace it. The coverage responded in both cases. The size of the check is what differs, and on the right loss that difference is enormous.
Why the roof is where it bites
Roofs are where this setting does the most damage, because roofs depreciate steadily over their life. An older roof, settled at actual cash value, might pay only a fraction of the replacement cost, because depreciation has already eaten most of the value before the claim begins. The owner is left covering the gap. This is one of the coverage gaps that cost landlords the most, and it is especially punishing on exactly the older properties that are most likely to have a roof claim in the first place.
The settlement basis stacks with the form
Settlement basis is one of two things that decide how a policy performs. The other is the policy form, DP1 versus DP3, which controls which causes of loss are covered at all. The cheapest landlord quotes frequently combine a narrow form with an actual cash value basis, which is a double limitation: fewer covered perils, and a smaller payout on the ones that are covered. That combination is how a low premium turns into a disappointing claim, and it is part of why shopping on price alone is risky.
How to tell which one you have
Pull your declarations page. The settlement basis is usually noted on the dwelling, and sometimes separately on the roof, as replacement cost or actual cash value. Watch for policies that apply actual cash value to the roof specifically while the rest of the structure is replacement cost, which is an increasingly common way carriers manage roof risk. If you cannot find it or cannot tell, that is normal, and it is one of the first things a review reads off the policy.
Making the right call
For most rentals, replacement cost is the stronger choice, and the premium difference over actual cash value is often smaller than owners expect, especially weighed against the gap it closes on an older building. Actual cash value has its place on certain hard-to-insure or unusual properties, but it should be a deliberate choice, not the accidental result of buying the cheapest quote. A coverage review reads your settlement basis, shows you what replacement cost would cost on your property, and makes sure you are choosing the basis on purpose rather than discovering it at a claim. It is not a quote. It is a straight read on how much of a loss your policy would actually pay.