9 different laws on land use – for each Bundesland one although regarding hydrogen production facilities the requirements do not differ that much; as example please see on the next line the land use plan of Vienna

National Legislation (Austria)
Regional legislation (adopted by parliament), Local / City text
Affected LAPs:
Land use plan (zone prohibition)
Production of hydrogen / Centralised (Electrolysis, Steam-Methane reforming, and H2 liquification)