I live at the 15th floor and am interested on a pair of window-mount antennas for the 40 meters band: a top-fed vertical; and a loaded monopole, which I've already used with pretty decent results.
I'd like to run some simulations of both on 4nec2, especially the monopole, with which I'd like to experiment using alternative positions and sizes of inductors and a capacitive hat.
However, I believe it would be important to simulate the effect performed by the building wall over the far-field pattern.
Is it possible to simulate it using 4nec2, either directly or using some sort of trick, like a grid of lossy conductors? I've tried to find some info on the internet, with no success so far.
I experimented "rotating" my design and using the ground as if it were the building wall. However, I believe there is a more appropriate way and, besides, this wouldn't allow me to simulate the top-fed vertical, since its end will be closer to the ground and, therefore, it's going to be under effect of both the ground and the building wall.