在workerthread上构建WPF UI？

I have to buil a rather complex WPF UI (a hughe Grid) in code (no xaml invloved). Is there a way to stop the main UI thread from blocking while beeing in the process of building the Grid? Are there some portions of building the UI that can be outsourced to a workerthread? What parts of UI creation actually have to be on the UI thread? I have to buil a rather complex WPF UI (a hughe