As mentioned before, an appraiser can generally choose from three approaches to determine value. One or two of these approaches will usually be most applicable, with the other approach or approaches usually being less useful. The appraiser has to think about the "scope of work", the type of value, the property itself, and the quality and quantity of data available for each approach. No overarching statement can be made that one approach or another is always better than one of the other approaches.
Real estate appraisal in Germany is partly codified by law. The federal Baugesetzbuch (abbr. BauGB, "German statutory code on building and construction'") contains guidelines on governing authorities, defines the term market value and refers to continuative rules (chapter 3, articles 192 ff.). Each municipality (city or administrative district) must form a Gutachterausschuss (appraisal committee), consisting of a chairman and honorary members. The committee gathers information on all real estate deals (it is mandatory to send a copy of each notarial purchase contract to the Gutachterausschuss) and includes it in the Kaufpreissammlung (purchase price database). Most committees publish an official real estate market report every two years, in which besides other information on comparables the land value is determined. The committees also perform appraisals on behalf of public authorities.
To qualify, the homestead property must have been uninhabitable for at least 30 days and affected owners must file a sworn application for Abatement of Taxes for Homestead Residential Improvements (DR-463) along with supporting documentation to the Property Appraiser. If approved, the Property Appraiser will issue an official written statement to the Tax Collector, who will calculate and issue the credit.