There is something uniquely fun, challenging and satisfying about designing stairs and in many ways is a good example of what architecture is all about.  You cannot just design any stair you want.  There are all kinds of restrictions in the building regs governing maximum risers and goings, minimum widths, how the banisters are set out and head heights.  These are not just there to stifle creativity and have evolved over time for good reason.  They set out not only what is safe and sensible but also what is comfortable and natural to go up and down.  Too steep a stair can be daunting and too shallow does not fit a typical stride and can also be uncomfortable to navigate.  If you omit the small overhang on the treads you risk missing your next step and hand rails need to be set at a height and diameter where your hand naturally falls to grip it.  Stairs fall into that design category of essential and functional objects that since typically requiring to be visible have developed unique aesthetics of their own- since you’ve got to have one it might as well be beautiful.  There are a thousand ways to detail a stair in every style and fashion.  This one winds round a useful cupboard to hide all those coats and shoes and we are opening up the ceiling on the landing above to bring light in through a new rooflight to the hall below.  I like a continuous hand rail with thin spindles, it is more expensive than separate posts and rails but very elegant and wonderfully comfy to walk up and glide down!