The Griswold house is actually an exterior set on Blondie Street on a Warner Brothers back lot in Burbank, CA, as is Todd and Margos house (the neighbors next door).  The house has been altered a lot to serve other movies, especially the interiors, which are also only a set, not a real house.  You can take a virtual tour of Blondie Street here.  The Griswold’s house is on the far left just as the virtual tour begins

According to the Warner Bros. website, Blondie Street was built to look like a suburban neighborhood. It has also been home to many movies and TV series, including American Beauty, Pleasantville, Gidget, Bewitched, The Partridge Family, and Eight is Enough. There are 12 residential homes on the street in a variety of styles (some with practical interiors).

The interiors were filmed at Warner Bros. Studios in Burbank, California.

The Griswold House is so popular that a miniature version complete with lights is now available at:

Clark Griswold House

Below are some images of the “Griswold” home as it appeared during the film.

Griswold Family Home Lights on

National Lampoon's Christmas Vacation House Home

Clark Griswold House National Lampoon's Christmas Vacation

Christmas Vacation House with Snow

Clark Griswold Family House Christmas Vacation National Lampoon's

Below is the “Griswold” home as it appeared in the movie Lethal Weapon

Lethal Weapon House Christmas Vacation

Below is the “Griswold” House as is appears today.

Griswold House Today