As Cumberland House was located on the south side of Pall Mall, overlooking St James's Park to the rear, it had a very shallow garden. The purpose of this unexecuted screen wall was to enclose the garden without blocking any light. From observation of the drawing it appears that evergreen plants were intended for installation on the screen, as it was their foliage, rather than the architecture, which would have provided a screen to the garden. The plants would therefore have needed to provide year-round coverage.