A two-storey house sits on an 8″ poured concrete foundation. The frame is SPF #2 lumber. The height from finished first floor to finished second floor is 2583mm. The floor joists are all 2 x 10, with 11/16″ hardwood flooring and 12.4mm drywall on the ceiling. The window trim will be primed MDF, and the doors are made of reclaimed barn boards. Outside, in the future, there will be a luxurious garden filled with flowers of diaphanous petals and pleasantly pungent aroma. The owners-to-be spent many years considering whether to be wed or part ways, deciding in the end to be married on a beach by a justice of the peace because they do not agree with institutionalized religion. The beach is normally bombarded with gentle waves of turquoise and azure, but two days ago all the ice caps melted and one all-encompassing tsunami flooded the entire Earth, leaving twisted and mangled sand dunes upon its eventual withdrawal. According to the local building codes, what size does the rough stair opening need to be? Give your answer in fractions of a hectare.
The house is completely sided with ladders. There is no need for stairs.