HDRI background reflection issue

[Autumnwind]

Hi everybody, I didn't find a solution to my problem, so I'm opening a new thread, hoping you have the solution.

I'm using a HDRI sky for my project, namely the beautiful packs by Peter Guthrie. They have a black base below the skydome, the problem is that when I make a render they get reflected and refracted through the glass of my windows (in some parts of the project I can see the horizon through two layers of glass).
How can I solve this problem? I would like to have just the sky reflected on my glass materials (and seen through them), not also the black "base" tint.
I din't construct a background surrounding for my project thet could cover it, cause I just find myself better doing it in Photoshop and because the project would be too heavy to render otherwise.

Thanks in advance

[Lupaz]

How about a vrayplane?

[Autumnwind]

I tried, it's nice but It is also reflected on the building and I would like to be bale to remove it in post production in photoshop, but in the "background" file I can select just the sky. Do you know of other possible solutions?