Ralf

A friend of mine told me that the communists started building these houses in Berlin in the late 40s to demonstrate their superiority over the capitalist world, but they were expensive to construct and at some point they switched to the ugly and cheaper Plattenbau. As far as I know, these were once affordable to buy after the “Wende” but are now quite pricey and rarely for sale/rent.

Are you really talking about the typical unsightly Plattenbau or the Stalinist architecture-style buildings, also known as Zuckerbäckerstil ("wedding cake style")?    https://en.wikipedia.org/wiki/Plattenbau   https://en.wikipedia.org/wiki/Stalinist_architecture

Thank you for rescuing the dog and giving him a good home!