Thanks for that. Yes-hubby has the power tools, so all good. After a lot of consideration, I've decided to dump the stairs this time. I was so hell bent on the design being "correct" ie stairs in the right place, lighting etc but I think for the first attempt, just keep it simple as I'm planning on making the furniture as well and just having fun. If we decide to make another one, then we'll start getting more technical :-)
I tried uploading a photo from my phone, but it kept saying it was too big. Any idea of how I resize it to send (though I need to redo my sketch now to get rid of the stairs)?