Escaping from a skyscraper, if it’s on fire for example, is always going to pose problems.
Since you often can’t use the lifts in an emergency, today’s invention provides a rapid route to the bottom for everyone -whether disabled or able-bodied.
A helter-skelter is built into the corner of each skyscraper as shown. This has access doors in the corner of every floor, so that occupants are in no doubt about their exit route. The helix itself would be made of fireproof material and have sliding mats attached to the interior surfaces.
People would be able to grab these and descend at a safe terminal sliding velocity to the bottom.
The slide would be made of one standard component, based on the (uniform) inter-window dimensions.
A fancier version might even be made to corkscrew upwards into position, from beneath ground level, breaking through windows when the building needed evacuated.