🔺️A Quarter-turn Spiral Staircase: A Step-by-Step Guide✒️

Hello everyone and welcome back. In this video we are going to tackle drawing a spiral staircase with a quarter circle plan. Now just like with any other staircase we've drawn so far, the first thing we need is a simple 2D plan to sketch out on the corner of our paper or our sheet. It really helps to have those basic dimensions down before we do anything else. To get that quarter circle shape I like to start with a simple L shape and then I just round off the corners. It starts to look like a quarter circle plan. The reason I do it this way is that this L shape method is really a lifesaver later when we have to draw this same plan in isometric view or different types of perspective. It really makes it easier. Alright so on this plan I've gone ahead and numbered the steps heights and I got 13 steps at 20 centimeters each. The height of each step is 20 centimeters. Now let's jump in the into the isometric view. I'll start by drawing the corner of the room. Basically we need to establish the floor level downstairs and the floor level upstairs to get started. Remember that trick I just showed you and the 2D plan? We're going to use it again here. Start with the L shape plan on the floor. Round off the corner and we have our quarter circle plan in isometric. Now if I divide that plan up I can start drawing each individual thread and I end up with 12 of them. Next up is figuring out the slope or the pitch of the stairs. For that we need three key points. The start, the middle and the end of the run. I'll connect these three points with a nice smooth curve and then do the same thing on the other side. That curve is our stairs slope. Now for the fun part. Drawing the steps one by one. To get the threads to sit perfectly on that slope, I take the lines of the threads from the plan below and project them up onto the slope line. Once they are in place, I can start building each step. See how the slope of the stairs gently turns as it rises? The threads follow that same rotation which is what creates that beautiful curved form of the staircase. The number of steps we have and the size of our initial plan all depend on the floor-to-floor height we calculate at the beginning. Don't forget to add the thickness to the steps and also show the thickness of the upper floor slab. What's a staircase without a railing, right? I'll go with a standard height of about one meter. I mark that height at the start, middle and the end of the stairs and then connect the dots making sure that the line follows the same slope as the stairs. We'll do the same for the railing on the other side. It's really amazing how even complex forms like this become so manageable when you just follow a logical process. Finally, I'll add some simple hatching to show the thickness of the steps and there you have it. We started at the floor and with 12 steps reached the height of 2 meters and 40 centimeters. I really hope you enjoyed it and you find this method helpful for drawing all kinds of stairs. Give it a try in your own sketches. See you soon!