I have to correct and clarify myself. Ground Floor is for multistory buildings, like Mixed Property.
In my building there are actually 6 Floors. But the last one is called 5-th Floor. More often they do not call that Ground Floor in any way. It's automatically for stores and other businesses.
In small houses though, like 1 Family, 2-3-4 Family houses with 1 to 3-4 floors, without any businesses downstairs they count them like in Europe. 1 2 3

Let me know if in future you will need to translate Domus in Russian. It has a GREAT potential.
(I was playing yesterday with SobiPro, that I used to like, when it was really free Sobi2 for Joomla 1.5, and I had to uninstall it today. Support for free. Even docs are for $. All plugins, everything - for $. Bunch of buttons just don't work with my template. Even to create e Menu for it you have to use External URL. Gallery is not even close to your beauty. Installation and configuration takes days, if you know what u r doing. Otherwise - probably months. That's why I was asking you to remove all real estate fields from Domus and leave it as a separate program for people. It's simple and looks terrific, and respond really fast on the website. People will LOVE you and that modified Domus)