What is the essential semantic difference between "sein" and "werden" for passive voice?

Answer 1

The verb "sein" cannot be used in German to express the passive voice. Instead, the verb "werden" must be used. For example, if you wanted to say "The house is built", that's "Das Haus wird gebaut" in Geman. In the past (The house was built), this would be "Das Haus wurde gebaut". However, to express the future, you have to use the verb "werden" twice, because "werden" is also used to express the future. Therefore "The house will be built" is "Das Haus wird gebaut werden".

Answer 2

The verb "sein" is not used to make the passive in German. The passive can only be made with the verb "werden", for example if you want to say "The house is built/ was build/ will be built", this is "Das Haus wird gebaut/ wurde gebaut/ wird gebaut werden".