That's the West mansion and it's completely off limits, private property. Supposedly it's owned by Hakeem Olajuwan curently and is protected from destruction until 2012. Portions of it have been removed, it used to have much more towards the body of water, but what's left is still obviously gorgeous.
http://www.preservedintime.org/Houst...%20Article.htm
Nearly very photographer in CL I've met has either at one time wanted to or still wants to shoot there. I've lived in Clear Lake since I was born and only once I've seen people actually shooting there once in 19 years (about 6-7 years ago). Folks (high school students) have snuck on property, and when caught they're asked to leave (yes, there is person living there)... not sure when they're not caught. But it is private property and off limits.
There's not much as far as something similar in the area, Tuscan Lakes maybe something faux-vintage, but you should try the Heritage Society homes at Sam Houston Park. It's not as a good, but they have some neat areas, and being so close to SHP you can work multiple looks in one trip.