As a fan of alternating tread stairs, and the owner of a rare city-permitted custom made set of them in the granny cottage I built, I’ve always been curious about one staircase option I did not use: the Arke Karina stair kit.

My own alternating tread device, like most I see around on the internet, was custom made out of wood by a carpenter, and is straight.  However the Arke kit uses a modular metal unit as its spine, giving it a lighter appearance, and giving it the ability to curve.  The Arke kit isn’t cheap ($1600 minimum, plus >$200 extra if you want a second handrail), though custom carpentry isn’t either.   Neither a custom made wood alternating tread stair, nor the Arke kit, meets most residential codes in the US so it’s a wash in that respect.  What’s the better choice for someone building or modding a small house?

I finally got a chance to see an Arke Karina kit in action, …more