Some information:
The series will last for 92 days. 12 housemates will move in on launch night. According to the host Jochen Bendel (who used to host the German answer to Uplate from 2003 to 2006, co-hosted the weekly live show during BB6 and hosted a BB late night show during last year's and this year's Promi BB) there won't be housemates that used to be on telly before or trying to make a career in television.
There will be indeed a brand new house for the new season built in the same studio complex as the Promi BB house, but at a different place within that studio complex.
The host branded the series as "back to basic". That means there'll be just one living area, no poor/rich divide. They won't do big challenges where housemates left the house (like they had during BB5, 6 and Promi BB 2), but there will be weekly tasks. Probably looking like the tasks on the earlier seasons.
You can read that here:
http://bbfun.de/news/big-brother-2015/big-brother-haus-konzept-1292922707.html - that site usually has good information about the show. They also had videos during Promi BB that weren't geoblocked. Not sure if they'll have some for the new regular series.
Back to basic is something they already did to some extent during the last Promi BB season. For most of the season, housemates were left on their own. They had duels during the daily live show and housemates upstairs had to name a housemate to move upstairs. Besides that there were hardly any tasks: When they had a male/female divide two guys had to do chores (stripping and being a butler for a doy). Later on one of the women had to clean upstairs when the guys lived there. Besides that, they did the ranking task once for each area of the house. (most famous housemates and housemates with the most fans).
The only twists they had was during nominations. They changed those up a few times. Nomination two people insteas of one (which is the rule in Germany), open nominations and once the person with the most points was able to select his opponent.
I don't know if it's smart to do something like this during the regular BB. German viewers tend to favour the divided houses and huge challenges. It's more about who achieves the most than who's the most entertaining housemate. That's why they have the basement for Promi BB. They want it to be tougher than I'm a Celebrity.
Also live feed viewers complain about boring live feeds when people don't have stuff to do. They expect to see action all day long. I guess most fans would even be happy with twisting things like they do on BBUK as long as it's some sort of entertainment. In fact there were quite a few people who praised every single bit of this year's CBB winter series, but couldn't name anything good about this year's Promi BB.
I think Promi BB started a bit slow, housemates were quite boring at first. But not having these huge challenges and matches during the day really gave the housemates time to shine and some of the housemates really surprised you with their behavior.. there was quite a huge development during the season and that was quite refreshing compared to later German series (where Big Brother gave lots of input) or recent UK series, where drama is scripted.