Sejie sent me the Grand Hyatt's building elevation. It shows the heights of course. I did a screen shot of both ends to show the heights. The elevation shows the building from the north side.
So...here are the official heights.
424 feet, 3 inches tall. This would be the official "architectural" height. This height is to the top of the parapet atop the mechanical penthouse. Parapet is just a fancy name for a wall. The parapet is 16 feet tall. It screens the some of the mechanical stuff. Probably the air conditioning units.
The 2nd highest height is 408 feet, 4 inches. This is the height to the roof of the mechanical penthouse. So if you were to stand atop the mechanical penthouse that's where you'd be, at 408 feet, 4 inches up.
The height to the parapet on the main roof is 388 feet, 9 inches high.
The height to the main roof slab level is 385 feet, 2 inches. This is the roof of the cabana area.
Highest occupied floor (floor 34) is 370 feet, 6 inches.
The cabana level which is above the 34th floor is at 372 feet, 6 inches.
The podium of the building at its highest point is 100 feet tall. ydoc14, remember that screen you were talking about on the base of the building? That screen is 100 feet tall.
And the rooftop pool area which is actually atop the 32nd floor is 350 feet above the street. This would make it one of the highest swimming pools in Texas.
Also note that there are 3 levels of mechanical use inside the mechanical penthouse. This is where the "37 floors" number was coming from. But since those levels are not occupied they aren't officially included in the building's floor count.
A few other observations. The 'Hyatt' sign on the side of the mechanical penthouse is likely 12 to 15 feet tall. The mechanical penthouse from the top to the main roof is 30 feet tall. From the top of the mechanical penthouse to the 32nd floor setback (where the pool is) is 74 feet tall. So the mechanical penthouse is really tall. I'd also estimate that it's probably about 75 feet long since it's nearly perfectly square.
This is the east end of the building (closest to I-37).
And this is the west end of the building.