Why are my WPF window sizes defaulting to be huge

Question

I have a wpf application with a few forms. At design time they are small, and they are not set to auto size. However at run time they are giant, even with no content in them

Answer 1

In design you are seeing small because you have blend design properties for the window.

d:DesignHeight="296" d:DesignWidth="634"

Since Grid is a dynamic layout it will be stretch to the window's width & height. To restrict you window size you need to mention Height & Width properties to the window.