Auto-Boom Housing Built Before Central Air Existed
Royal Oak's population grew from about 1,000 in 1910 to roughly 23,000 by 1930 after its 1921 incorporation, and most of that construction predates residential central air conditioning by decades -- bungalow-style homes built for a booming auto-industry workforce, not for modern HVAC equipment.
Ductwork Retrofits Are the Norm, Not the Exception
A system replacement in one of these 1920s-era homes almost always means working within duct routing that was added well after the house was originally built, since nothing resembling whole-house forced air existed anywhere near Royal Oak when these blocks went up.
HVAC Project Paths in Royal Oak
What a Royal Oak Estimate Should Cover
Given how uniform the 1920s construction wave was across Royal Oak, an HVAC quote should note whether a home's ductwork has already been retrofitted once, and how much of the original routing is still in use.