The law courts must appear as a threatening gesture toward secret vice. The bank must declare: here your money is secure and well looked after by honest people.
The work of art is brought into the world without there being a need for it. The house satisfies a requirement. The work of art is responsible to none; the house is responsible to everyone. The work of art wants to draw people out of their state of comfort.
The work of art shows people new directions and thinks of the future. The house thinks of the present.
If nothing were left of an extinct race but a single button, I would be able to infer, form the shape of that button, how these people dressed, built their houses, how they lived, what was their religion, their art, their mentality.