Spooky's assensing shows the aura of a single metahuman inside the apartment. The window is the kitchen's, the person is sitting in the living room.
He or she is well at ease and awakened.
The fire escape's strength is hard to judge. Boomer and Rat climbed a very similar looking before, on the other side of the alley, and Spooky's on it already. So you know it can hold a person. But how many or how long? Hard to say, the thing's obviously seen its best day. It's bound to have some weak spots that are rusted through, just waiting for someone to put their weight on them.