From the pictures it looks like the deck is bigger than the house

This is obviously a huge house and the style of the deck (and the archways under the deck) are lovely and enhance the entire structure. However, those stairs are outrageous and a very obvious safety hazard! As Alice (above) said, not only do the stairs overwhelm the entire house, they're cutting off outside light to (and views from) the lowest level of the structure. Additionally, since most people descending the stairs will be holding onto one of the handrails (if there are any in the center, I can't see them), the cost for the massive amount of material and labor, which must have gone into building such a wide staircase, is virtually wasted! The quality of the materials and workmanship may be excellent (a few close-up photos would answer that question), but the judgment of adding such a staircase was a poor one. If the goal was to add an aesthetically elegant, but safe, stairway, other design options were available. The first time someone's child or grandma falls off the deck and rolls down the center of the stairway, the homeowners will understand what a poor decision it was.