Invasiveness is like real estate, it's all about location, location, location!

I would not choose this grass along the west coast for sure. I don't see what zone you are in, but if you are concerned, there are lots of other grasses to try. There are also some varieties of cortaderia that do not spread or seed so readily. Some of the compact and variegated varieties are quite attractive and very controllable. There are also areas where cortaderia selloanna has no invasive concerns.

There are some species of cortaderia that can be very widespread and a concern. Cortaderia jubata is one.

If you are in a suitable planting area for cortaderia, I would still not suggest planting along a house or foundation. This is not where it is best suited. It is large and difficult to remove/transplant. It is better suited as a specimen where space is a luxury. There are better selections, but your zone will dictate those.

You sure gave me alot of helpful advice and alot to think about. Thanks