Yes, in a house, they form only part of the house. But before that, someone has to own the land and equipment that gets those bricks out of the ground, and the kiln that fires them, etc. And the materials for the kiln have to be sourced and built.
The point is, the bricks do not materialize out of thin air. The act of laying the bricks is not the only labor or capital involved in laying bricks.
Yes, in a house, they form only part of the house. But before that, someone has to own the land and equipment that gets those bricks out of the ground, and the kiln that fires them, etc. And the materials for the kiln have to be sourced and built.
The point is, the bricks do not materialize out of thin air. The act of laying the bricks is not the only labor or capital involved in laying bricks.