The house which Equality 7-2521 and Liberty 5-3000, whom he calls the Golden One find while they escape into the Uncharted Forest was one built during the Unmentionable Times and had been left undamaged.
It had 2 stories and a flat roof. The walls of the house were made of a kind of stone that they had never seen before, which I guess refers to concrete.
The house was bright and colorful with light pouring in through the glass windows that made up a large part of the walls. It looked very small to them when they compared it to the large halls built for hundreds to live in that they were used to.
All the rooms of the house were lined with bulbs like the one Equality had found and knew its purpose was to light up the house. There were mirrors which allowed them to see themselves and appreciate who they were, distinct from the rest.
The most surprising aspect of the house was the bedroom in the house which had only two beds, and they knew that the house had been made for only two people to live in. Equality's narration after seeing the bedroom in the house sums up what they felt about the house.
We found the sleeping hall and we stood in awe upon its threshold. For it was a small room and there were only two beds in it. We found no other beds in the house, and then we knew that only two had lived here, and this passes understanding. What kind of world did they have, the men of the Unmentionable Times?