Quick answer
There’s no official dollar line, but a common industry marker is a home with a rebuild cost above $500,000, which is where many standard homeowners policies stop offering full dwelling coverage entirely. In practice, “high-value” is less about a specific number and more about whether your home’s actual replacement cost, construction quality, and contents exceed what a standard policy was built to price.
A newer custom build with premium finishes, a historic property with restoration requirements, a home with a significant collection of art or valuables inside it, or a property with liability exposure well above a standard policy’s limits are all cases where “high-value” applies regardless of the exact appraised number. The clearest way to know for certain is a full asset review, which looks at your specific property rather than a generic threshold.