Taxes are suppose to keep this from going out of control. but the only way to appeal a tax appraisal increase (here in Washington) is to use OTHER home values in the area that are similar, but less.
Mortgage appraisals are far higher than the local tax appraisals which seem to run 20-25% lower than say Zillow says. Local tax appraisals are also typically only updated once every 10 years or so (depending on the jurisdiction).
Besides, I think these days the appraisers don't actually do appraisals, they just look at Zillow.
The people that do appraisals for property tax assessment reasons may be the most disliked people in municipality. My opinion is that it makes no sense for people to be doing it anymore. It should be strictly algorithmic with very few input variables.
