Across the wider Saginaw service area, most housing stock dates from the 1950s through the 1990s, with a lot of neighborhoods concentrated in the 1960s and 70s. Zilwaukee's own median build year of 1960 puts it right at the older end of that range. Doors from that era, if they've never been replaced, are usually single-layer steel or older wood panel, with hardware that predates the torsion-spring safety standards common now. The bigger factor is the climate this area sits in - a cold, severe winter band - which is hard on any door that's aging out, insulated or not. Panels that have taken decades of freeze-thaw cycling warp at the seams, and tracks that were never insulated well let ice build up at the bottom panel. None of this is unique to one street in Zilwaukee; it's a function of when the house was built and what the winters here do to it.