Well the long grey structures are actually bunkers, they seem to be made of concrete and designed to endure a bombing run or a very misbehaving rocket. The UR500 was supposed to be the mother of all ICBMs so having big storage bunkers near the pads make sense.
By "houses" I meant the metal "boxes" you have on each side atop the mobile tower, not any ground structure, those are rather well documented in the ILS manual.