Adding a face in a model

I’m following this tutorial on youtube right now:

And somewhere along the way I managed to mess up and lose a piece of my roof on the house. You can see it here:

Anyone have a suggest for a quick/easy way to put a piece back in there?

Assuming that there is no face there (not a hidden face) select the three sides and press F

If that doesn’t work there may be more problems with the mesh so include a download link to your blend file

Alternatively -

There were no hidden faces, so that worked out perfectly. Thank you much!