Spokane has old housing stock. According to Spokane County Assessor data published by the City of Spokane, about 19% of the city's housing units were built before 1940, and roughly 42% went up before 1970. The average single-family detached home here is around 70 years old. That matters, because the decade a house was built tells you most of what you need to know about what is behind its walls.
Before 1940: knob-and-tube
Knob-and-tube was the standard wiring method from the 1880s into the 1940s. Individual conductors run through ceramic tubes where they pass through framing and are supported by ceramic knobs along the way. There is no ground conductor. The system was never designed for one.
It is not automatically an emergency. What matters is whether it is still energized, whether it has been buried under later insulation, and how many decades of amateur splices it has accumulated. Insurance carriers have grown steadily less willing to write policies on actively energized knob-and-tube. We go into that in more detail here.
The 1920s through 1950s: cloth-jacketed cable and fuse boxes
Early non-metallic sheathed cable (what most people call Romex) has been in use since about 1926. The early versions used rubber and cloth for insulation, and cloth does not age well. It dries out, gets brittle, and crumbles when disturbed, which is why an electrician working in a 1940s attic moves slowly.
Homes from this era commonly still have fuse boxes or 60-amp services. That was adequate for a house with a few lights, a radio and an icebox. It is not adequate for a modern kitchen, let alone a heat pump or an EV charger.
1950 to 1970: the transition, and the 1962 line
Plastic-jacketed cable started replacing rubber and cloth in the 1950s, but the handoff was gradual, roughly 1950 to 1970 depending on the builder and the region. A house built in 1955 can easily have cloth-jacketed, ungrounded cable.
The most useful single date for a homeowner is 1962. Grounded three-slot receptacles were required in the laundry starting in 1947, extended to outdoors, garages and basements in the 1956 code, and it was the 1962 edition that first required them throughout the home. If your house predates 1962, it was not required to have grounded outlets everywhere, and many did not.
This is why two-prong outlets are so common in Spokane. It is also why simply swapping a two-prong receptacle for a three-prong one is not a fix: without a ground path behind it, the new outlet just looks safer.
1965 to 1973: aluminum branch circuits
For roughly eight years, aluminum was used for branch-circuit wiring in homes. It expands and contracts differently than copper, which over decades can loosen connections at outlets and switches. Homes from this window are worth having looked at. The fix is usually about the connections rather than replacing every run.
What this looks like neighborhood by neighborhood
Spokane's neighborhoods were built in waves, so the wiring tends to cluster.
- Browne's Addition: built overwhelmingly between 1881 and 1910. Roughly two-thirds of the buildings standing today were up by 1910. This is the city's densest concentration of original knob-and-tube-era housing.
- The South Hill, around Cannon Hill and Manito: the streetcar era from 1899 to 1930 accounts for most of what is still standing. Craftsman homes dominate.
- Comstock: mostly postwar, with the boom running from the 1940s into the 1960s. This is fuse-box and early ungrounded-cable territory rather than knob-and-tube.
- Chief Garry Park: genuinely split. Homes along and south of Mission Avenue largely went up between 1900 and 1930; most north of Mission are postwar. One neighborhood, two different wiring eras, with a street as the dividing line.
We work in all of these neighborhoods, see our pages for the South Hill, Browne's Addition, and Comstock.
One caution about all of this
Build decade tells you what to expect, not what you have. Remodels move things around, previous owners add circuits, and knob-and-tube in particular kept getting installed in some places long after it fell out of general use. Nobody can tell you what is in your walls without opening a panel and looking.
What to actually do with this
If your house predates 1970, the useful next step is not a full rewire quote. It is knowing what you have: what the service size is, what is actually energized, whether there is a ground path, and what an insurer is likely to flag. From there the answer might be a service upgrade, a handful of circuits, or nothing urgent at all.
If it does come to more work, here's what home rewiring and a panel upgrade actually involve.
Filed under Electrical Safety.