In a house with one stair, everybody meets there. That sounds obvious and it changes the plan completely — it means the stair cannot be tucked into a corner, and it means its material has to survive being the most-touched surface in the building.
Stone, and only stone
We have used basalt, granite and, once, a very hard limestone. Timber treads look beautiful for four years. Carpeted stairs are a decision made by someone who has not lived with children.
The handrail argument
Nearly every client asks for a glass balustrade and nearly every client changes their mind on site, because a glass balustrade in a stone stair reads as an afterthought. A steel flat, 12 mm, painted to match the shadow gaps, disappears completely.