Building That House er Novel

I recently finished reading an enthralling novel, 'No Time For Goodbyes'. In an interview the Canadian author, Linward Barclay, was asked how he began with the idea to form the story. He said "Once you come up with a premise, you have to work out how the story unfolds." Well that's fairly obvious. But what he said next got me. 

"It's a bit like coming up with a spectacular roof design first. Before you can get it up there, you need to build a solid foundation and supporting structure."

Yes, that's exactly what I've been working on. I had an unusual idea first, and since then I've been steadily building on the structure, walls and windows, you know, supporting the original idea and letting in glimpses of light so the reader has an idea what's coming, but a little unsure. (Can't give away the plot can you?)

Now you'd think I'd have worked on the foundation first. I tried that but it wasn't too solid so I've been going back, (actually several times so far) and shoring up the groundwork.  I really don't think I could have begun with the foundation first - unlike building a house - because the background could only be written afterward.  You see, I had several different directions (plans) but just had to try out each one before BINGO, it worked. Now i have my solid foundation.

Incidentally, I'm so glad a house isn't built like that or it'd be a disaster. Brick by brick it goes up according to the exact plan. Hah! Many of us pantsers wouldn't be able to work that way. We like our characters to surprise us. That is, after we've fleshed them out, they have their own ideas how they'd react.

I can't wait to get to the roof. That's where my original idea will climax, wrapping up the whole plot. Does this make sense to you when you get your first idea? Or do you know the end from the beginning and then start building?