Most of the houses we work on in this part of Snohomish County went up between 1968 and 2000, with the median build year landing around 1990. That's the backbone of what we see on a truck: 30-to-50-year-old sectional doors, openers on their second or third capacitor, and torsion springs that are due whether anyone's noticed yet or not.
The closest spots to our shop - Port Gardner, Bayside, Pinehurst-Beverly Park, View Ridge Madison, Northwest Everett, and Boulevard Bluffs, all inside 4 miles - sit on the older end of that range, often pre-1980s construction mixed in with the newer wave. Out past 5 miles, in Snohomish, Mukilteo, Machias, Lake Stickney, and Silver Firs, you get a heavier run of 1980s-90s stock, the kind of standardized builder-grade doors that came in by the thousand during that boom. Farther out - Clinton, Martha Lake, Cathcart, Lochsloy, Three Lakes, and on toward Monroe, Maltby, and Arlington at 12 to 14 miles - the housing spans a wider range of eras across those 36 named areas, so the common fault shifts house to house rather than street to street.
We don't have a breakdown of exact ages for each of the 36 areas individually, just the overall pattern: older doors near the center, more uniform 80s/90s stock in the middle ring, and a wider mix the farther you get from Everett.