Thank you SO much Anidusa Carolina. As it turns out, the blue grid lines do not matter for my current purposes. I will do as you say, and I think I should have what I need. I picked this particular home because I want a big square space. That's all I really need right now. So I'm good on the limited design. I may come back and reconsider at a future point.
One other question, since you seem to be quite knowledgable. I am wondering if it is possible to import SketchUp models into SL. I'm an architect and have a number of models I'd love to play with in SL, but they are quite detailed, so the SketchUp import is what would make this feasible.
Thanks again for your help! Exactly what I needed.