The building is old, looks like a student shared apartment but it's really good for budget traveler. You will have your own room with private keys, well-shared kitchen and bathrooms and the location is just great! It's just 5' to either train station or bus stop, 3 difference kinds of supermarkets and domestic shops are around you in the corner and the best thing Dominik is really good in communication.
Highly recommend this place and I will get back when I go to Vienna again. Thanks Dominik & his brother!