In addition to cities and mansions, I was sometimes able to see decorative elements, such as those that appear on stairways and main doors. These elements moved as if they were alive, and changed with ever fresh beauty and symmetry. I learned that such changes can keep going indefinitely, one after another, even to eternity, and there is a constantly renewed harmony among the variations, formed by the very sequence of changes itself. These were only the least of their wonders, I heard.
All angels have their own houses to live in—magnificent houses. While there, I saw them several times, with astonishment, and spoke with the angels in them. They are so clear to see, so visible, that nothing could be more so. Houses on earth are almost nothing by comparison. Angels also call earthly dwellings lifeless and unreal but their own dwellings alive and genuine, because they come from the Lord. The architecture is such that it is the source of the art itself, with unending variety.
They said that if they were given all the palaces in the whole inhabited world, they would not exchange their own for them. Anything made of stone, brick, or plank seems dead to them, but anything from the Lord, or from life and light itself, is alive. Such materials are all the more alive because angels experience them with the full range of senses, since objects there are perfectly suited to the senses of spirits and angels. Objects in the light of the sun’s realm are not the least bit visible to spirits’ eyes. To the senses we have in our bodies, though, stone and wood are well-suited. What is spiritual responds to what is spiritual, and what is physical responds to what is physical.
from Secrets of Heaven, Volume 2, Sections 1627, 1628