On the topic - Oblivion/NWN/Baldur's Gate load in the interior of houses as different levels. Gothic doesn't. Both methods have advantages and disadvantages - which do you prefer ?

I don't mind having a loading screen from time to time. For example when traveling long distances. But if the levels are too small (every house a separate level) then it could get annoying and distract from the game.

If you can create the feeling of a seamless world with this streaming in 'in between' levels it would be really great! <img src="/ubbthreads/images/graemlins/up.gif" alt="" />

Assuming that you would have a city in a separate level I would prefer being able to enter (normal) houses without a loading screen. A very big city could be divided into different district levels to keep memory usage low.

Very large buildings or dungeons could be different levels. But you could easily do the streaming in the hallway of a large building while you talk to the butler who lets you in. In large dungeons the streaming could be done in the first passage before you open the next door.

So if possible go for the Gothic style where you can enter houses without a loading screen. Where you can look in and out of windows and doors.