Brycetech: Make a Building in Bryce

For the fire escape, create a gray scale image as the basis of a terrain for an escape door just like you did for the window frame.
Make your door as detailed as you want.       Here I made a terrain as the basis of the door to give it detail and another texture.
For the grating that a person would walk on, create another lattice and put a different grayscale image as its basis.   Remember to clip all of these! I always use 1024 x 1024 as the resolution for lattices and terrains.  Since this object is in the distance, I didn't worry too much about making all the lines intersect evenly.
For the stair opening make a different grayscale.
For the rails, create cubes, elongate and reposition to make a nice rail to go with your escape. You could just as easily done this with another lattice.
Group all of these objects and duplicate and reposition to make multiple levels of your fire escape.

In the final image, I created multiple cubes (on the corner in camera view) and positioned them at the building's edge to not only give detail, but to make it slightly different than the building in the foreground.   Don't make all of your buildings in a scene exactly the same. Later I added some radial lights inside of the building to give the appearance of lights turned on and off in the building itself.
Have fun making your own buildings!

Site Note:

Here you got a look at reducing "replay" in your image maps.  Using a terrain or lattice will save not only RAM but render time in large objects.  Keep that in mind in all of your images.  This is of course just one way to make a building in Bryce.  You may want to look at the building in the Explosion Tutorial to see another example.

This is not meant to be an all inclusive instruction on every possible way to have made the final image or produce the desired results.  Bryce offers zillions of wonderful ways to replicate, multireplicate, reposition, etc.  in its powerful interface. Experiment!