Betterment
A deduction an insurer can sometimes apply when a repair unavoidably leaves a property in better condition than it was before the loss, distinct from a code-required upgrade covered separately under [[concept-ordinance-or-law-coverage|ordinance or law coverage]], which usually isn't treated as betterment.
Why it matters
Betterment is easy to apply incorrectly, since it's genuinely hard to draw the line between "this repair happened to improve the property" and "this upgrade was legally required and should be covered separately."
On a real project
A single outdated electrical panel is replaced along with damaged wiring during a covered repair, since code no longer allows the old panel type to be reused. The insurer treats the panel upgrade as ordinance-or-law coverage rather than deducting it as betterment, since it wasn't optional.
Who this matters most to
An Insurance Adjuster has to decide, item by item, whether an upgrade counts as betterment or as a required code upgrade, since the two get handled completely differently on the claim.
Where this goes wrong
An adjuster applies a betterment deduction to a code-required upgrade, like adding a required fire-rated door during a repair, that's actually covered separately under the policy's ordinance-or-law coverage. That incorrect deduction shortchanges the policyholder for an upgrade they were legitimately entitled to have paid for.