Tornado damage insurance question?

It's going to depend on your particular policy, but most of the time, they only replace the siding on the side of the house that was DAMAGED. You'll have to ask your agent, if you have a "matching" clause.

There are no 'sites' because it's up to your policy terms.

They only pay to replace the affected areas.

If only 1 side of the home was damaged, then they may patch that side or replace that side - depending on how extensive the damage is. They will not replace all the siding on the house just because 1 side is damaged.

Most policies state that they do not owe you an exact decorative match.

So, if only 1 side of your home needs to be replaced but the siding is 25 years old, they will still replace the 1 damaged side. They will pay for something that is as close to what you had as they can get. However, they will not reside the entire house just because they can not get you an exact match.

Additionally, you can't find any sites with a % because there is no %. Each claim is evaluated on it's own merits.

It's not by percentage, it's by number of sides. If you've got two sides with non-repairable damage (that means, they don't make that kind/size/color any more, or they can't match it), then they replace the siding on the entire house.

If they can't match the siding they will have to replace all of it. I've never heard of a set percentage. Talk to your agent. He/she knows your policy.