Modify stairs

[RedHerring2]

have you thought about a newel post and connecting the stringers to the landing....

If it's a quarter turn you want and you intend to construct a self-supporting stable landing, then there's a real possibility of modifying the stairs to meet the new landing.

If you construct the landing about 50mm wider (from the quarter turn flight) or longer ( from the main run flight), then the stringers may be modifyable. By notching out a 50mm wide piece from the bottom of the stringers where it will sit on the new landing, and ensuring the new landing is not going to move anywhere, the stairs should be perfectly stable.

Alternatively a 75mm X 50mm piece of timber across the back of the new landing to support the bottom of the stairs.

The benefit of the notch in the stringers is the support from underneath and the prevention of any travel..