Designed by Paul Lafrance and built on HGTV's "Decked Out" episode, "The Spiral Staircase Deck". Watch the construction on HGTV's website:
http://www.hgtv.ca/deckedout/video/season+2/the+spiral+staircase+deck/video.html?v=2238693989&p=1&s=dd#deckedout/video/season+2

Margaret and Dan have a large private backyard they love. The problem is they have no way to get to it from their current deck. The challenge: how do you get from a top deck to a bottom deck without having stairs taking up valuable space? Answer: a spiral staircase. Paul and the team come into this project inspired and build an incredible space that includes an upper deck with a metal spiral staircase leading to a lower deck with a hot tub area (with a motorized gazebo-like cover), bar and lounge, which then leads to a circular aerial structure with a circular stone pad beneath. Now that they can get to their yard, they’ll never want to leave.