They had an opening in the middle of their house which was called a "compluvium". There was either a indoor garden in the middle or...
and "atrium" (or hall) or both.
Under the left roof flap:
They had no electricity and used oil lamps.
There is a mural of the countryside painted on the far wall.
They had no windows onto the busy (and noisy) street.
Rich families had piped in water and even their own lavatory.
The house flaps to the left.
They invented underfloor heating. This is a photo of the ruins showing the pillars under the floor.
and "atrium" (or hall) or both.
Under the left roof flap:
They had no electricity and used oil lamps.
There is a mural of the countryside painted on the far wall.
They had no windows onto the busy (and noisy) street.
Rich families had piped in water and even their own lavatory.
The house flaps to the left.
They invented underfloor heating. This is a photo of the ruins showing the pillars under the floor.
The photo flaps to the left.
This explains how it worked.