In Vienna, parking space obligations are strictly regulated by the Viennese Garages Act from 2008. If you are about to build yourself a home and think that you are not in need of a parking space, then you are no longer obligated to build one as the owner of a single-family house.
According to the Viennese Construction Ordinance, single-family houses are “small houses with a residential unit” and equal allotment residential houses and allotment houses (§50). There is NO parking space obligation for that kind of building.
For further (german) information click here.