The clients' purchased a large house in Encino sited at the end of a ridge. It was a great house on a great site, but poorly constructed. Over a year of construction kept uncovering more and more problems with how the original house was constructed.
The design work was interesting, although a lot of it was small scale fixes to the original house. Although it was presented as a French chateau, the interior spaces often lacked the sort of formal definition that style would suggest. This lent an unresolved feeling to a lot of the rooms, and moving between them was not satisfying.
The worst of them was the main space, because it was a huge barn of a space with a balcony dividing the Entry from the Living Room but without real separation between the two. By redesigning the balcony to have a solid rail and the stair to have the same, and by dropping the ceiling over the balcony, we more carefully defined the two spaces.
We termed these fixes syntactic corrections and we probably did little more than a dozen of them in all, through a house that was nearly ten thousand square feet. The end result was that the house is much more cohesive. There were a lot of strange design decisions in the original design. There were two powder rooms and one of them had the door in the main entry space, when it was very easy to have it around the corner in the hallway instead. (Where it was just as easy to find, but it was more difficult to wind up looking into a toilet space when you first walk into the house.)
The work too much longer than expected, and was obviously more expensive than we had originally planned. (All of the flashing around the chimnies and parapet walls was done incorrectly. The decking on the terrace was lapped in the wrong direction and so forth.) The end result was stunning.