Is this a residential wood frame building with traditional single or double hung windows or is this a condo building with aluminum windowsI assume you already confirmed the windows are a common element

My house has aluminum wiring (one breaker is copper, the rest aluminum), a federal pacific box, and a couple other electrical projects. 

Many duplexes built around here are traditional up/down stick frame duplexes sided with either wood. vinyl or aluminum.

@Bruce Woodruff yes it could be aluminum or knob and tube for all we know.

Aluminum Grounded?

I racked my brain for a simple hack, and what I came up with was disposable aluminum roaster pan inserts that had holes punched in straight from the dollar store.

  ". . .John Ladd’s cattle ranch in southeastern Arizona.

Even old wood windows can often be fixed with some sanding and paint.Single pane, raw aluminum is ugly and old wood frame is a pain to operate but they work well enough and not replacing them helps me keep my rents within reach for families who need affordable housing.In some cases I will replace a single window in a house if the frame is destroyed but I never do the whole house.

Windows ~$150/opening and aluminum ~$20/opening.

I replaced an old aluminum window with glass block.