Homeowners across Pasadena are starting to hear a phrase they never expected from their insurance company: knob and tube wiring. If you own one of the city’s early 1900s Craftsman homes, that phrase can show up in a renewal letter, a mortgage application, or a call from your agent, and it usually means one thing. Your insurer wants proof that the old wiring behind your walls will not start a fire.
This is not a Pasadena rumor. Insurance carriers across California have been tightening their underwriting rules for older electrical systems, and knob and tube wiring sits near the top of the list. For a city where more than 800 Craftsman bungalows still stand in Bungalow Heaven alone, this shift affects a real slice of the housing stock, not just a handful of outliers.
What Knob and Tube Wiring Actually Is
Knob and tube wiring was the standard method of running electricity through a house from the late 1800s until roughly the 1940s. Individual hot and neutral wires run separately through the walls and attic, held in place by ceramic knobs and passed through ceramic tubes wherever they cross wood framing. There is no ground wire in the system, and no sheathing binding the two conductors together the way modern cable does.
When it was installed, knob and tube wiring was actually a reasonable design for the electrical loads of the era. A 1910 home did not need to run a refrigerator, a microwave, a window air conditioner, and a phone charger off the same circuit. Today’s homes do, and that mismatch between old wiring and modern demand is exactly what worries insurers.
Why Insurers Changed Their Stance
For years, many California insurers quietly accepted knob and tube wiring as long as a home had no obvious problems. That has changed. Reporting on the Bay Area has documented insurers denying or canceling coverage specifically because a home still has active knob and tube wiring, and brokers around the state describe the same pattern. One insurance brokerage put it bluntly, stating that knob and tube wiring is now all but uninsurable in the current California homeowners market.
The reasoning lines up with national fire data. Electrical distribution equipment, meaning the wiring, panels, and outlets that carry power through a home, is a leading source of home fire property damage every year, and older systems without grounding carry a disproportionate share of that risk according to fire loss research compiled from NFPA reporting. Insurers are not guessing when they flag knob and tube. They are pricing a documented risk.
What Actually Triggers the Conversation
Most Pasadena homeowners do not go looking for this issue. It finds them. The three most common triggers are a home sale, a mortgage refinance, and a standard policy renewal where the carrier orders a fresh inspection or aerial review of the property. In any of these situations, an underwriter who spots signs of an older electrical system will typically ask for one of two things: written confirmation from a licensed electrician that the wiring is inactive, or a plan and timeline to replace it.
If you are selling a Bungalow Heaven or Madison Heights home this year, expect this question to come up during escrow. Buyers’ lenders are just as sensitive to insurability as the buyers themselves, since a home that cannot be insured cannot be financed on standard terms.
How to Find Out If Your Home Has It
Some signs are visible without opening a wall. Two-prong outlets with no ground slot, ceramic knobs visible in an unfinished attic or basement, and a fuse box instead of a modern breaker panel are all strong indicators. Cloth-covered wiring insulation, which often looks tan or black and brittle, is another giveaway.
None of these signs are proof on their own, and a home can have knob and tube wiring in some circuits while other rooms were rewired during a past remodel. That is why a proper answer requires a licensed electrical safety inspection rather than a guess based on outlet style alone.
What an Electrician Actually Checks
A real inspection goes further than looking at outlet covers. An electrician traces circuits from the panel, checks attic and crawl space runs where knob and tube is usually easiest to confirm, and tests whether flagged circuits are still carrying live current or were already abandoned during an earlier partial upgrade. That distinction matters, because insurers generally care about active knob and tube, not wiring that has already been safely deactivated and capped.
“The insurance letter is usually the first time a homeowner hears the term knob and tube, but it is rarely the first sign. We usually find two-prong outlets and an old fuse box the moment we walk in. Getting ahead of it before a renewal notice arrives saves a lot of stress.”
Razmik, Blue Moon Electrical
The report from that inspection becomes the document you hand to your insurance agent or underwriter, whether it confirms the wiring is inactive or lays out what needs to change.
Ask for this report in writing rather than a verbal summary. Insurance underwriters generally want a dated document on company letterhead describing exactly what was found, which circuits are affected, and what action is planned or already complete, since a verbal assurance from a homeowner carries no weight in the underwriting file.
Your Options Once Knob and Tube Is Confirmed
If an inspection confirms active knob and tube wiring, homeowners generally have three paths. The first is a full rewire, which replaces the old wiring with modern grounded cable throughout the home. The second is a partial rewire limited to the circuits an insurer specifically flagged, which can work as an interim step but does not always satisfy every carrier. The third is deactivating the old wiring entirely and running new circuits in its place, which is effectively a rewire done in phases to minimize disruption to a home’s plaster walls and original trim.
For Craftsman homes in Bungalow Heaven, Garfield Heights, and Madison Heights, the phased approach is usually the most practical. It lets a family keep living in the home while a whole home rewiring project moves room by room, and it keeps wall and ceiling openings to the minimum needed to fish new wire through existing pathways.
Why This Matters Beyond the Insurance Letter
An insurance non-renewal is a forcing function, but it is not the only reason to care about this issue. Knob and tube wiring has no ground, which means it cannot safely support GFCI protection in kitchens and bathrooms the way current code requires. It also was never designed for the number of devices, chargers, and appliances a modern household runs at once, and overloaded circuits on old wiring are a known contributor to home electrical fires.
Addressing it before a renewal notice forces the issue also gives you more control over timing, budget, and how much of the work happens at once, rather than scrambling to satisfy a short insurer deadline.
A Few Myths Worth Clearing Up
Some homeowners assume that if the wiring has worked fine for decades, it must still be safe. Knob and tube wiring does not fail on a schedule. It fails when insulation dries out and cracks, when a splice loosens, or when a circuit is asked to carry more load than it was ever designed for, and none of those things announce themselves in advance.
Others assume replacing a few outlets or adding a modern breaker panel automatically resolves the insurance issue. It usually does not, since the panel and the branch wiring running to each outlet are two separate systems. A new panel does not change what kind of wire is actually feeding your bedroom or kitchen circuits.
What a Phased Rewire Actually Looks Like
A phased rewire usually starts with the areas an inspection flags as highest priority, often the kitchen and bathrooms where GFCI protection matters most, followed by bedrooms and common living spaces, and finishing with attic and exterior circuits. Each visit typically closes out one section of the home completely rather than leaving multiple rooms half finished at once.
Electricians working in Bungalow Heaven, Garfield Heights, or the Arroyo Terrace district plan their access points around a home’s original woodwork and plaster, often fishing new wire through existing chases and attic runs instead of cutting fresh openings wherever possible. When an opening is unavoidable, it is usually small, patchable, and placed somewhere it will not disturb visible trim or built-in cabinetry.
Most families stay in the home throughout this process. Power to finished sections is typically only interrupted for short windows during final connections, and the crew coordinates around a household’s daily routine rather than shutting the whole house down for the length of the project.
How Pasadena Compares to Other Older California Markets
Pasadena is not alone in facing this issue, but its concentration of intact early-1900s housing makes the exposure larger than in many neighboring cities. San Francisco has drawn most of the recent press coverage on insurance non-renewals tied to knob and tube wiring, largely because so much of that city’s housing predates 1950 as well. Pasadena’s Craftsman districts share the same underlying risk profile, even though the insurance story here has drawn less attention so far.
That gap in attention can work against homeowners who assume this is strictly a Bay Area problem. Underwriting rules that start in one California market tend to spread statewide within a policy cycle or two, since carriers generally do not write different standards city by city. A Pasadena homeowner who waits for local news coverage before addressing active knob and tube wiring may already be past the point of getting ahead of a renewal notice.
Questions Worth Asking Before You Hire an Electrician
Not every electrician who advertises rewiring work has deep experience with pre-1940s Craftsman construction specifically. Before hiring anyone for this kind of project, it is reasonable to ask how many knob and tube jobs they have completed in Pasadena’s historic districts, whether they provide a written inspection report suitable for an insurance carrier, and how they plan to protect original plaster, trim, and built-ins during the work.
It is also worth asking directly how they handle permitting and coordination with Pasadena Water and Power, since a contractor unfamiliar with the city’s municipal utility process can end up adding weeks to a project that should move in a matter of days once work actually begins.
What This Means If You Are Buying or Selling
Buyers touring a Bungalow Heaven or Madison Heights listing should ask directly whether the home’s original wiring has been addressed, rather than assuming a renovated kitchen means the whole electrical system was updated. Sellers benefit from having a current inspection report ready before listing, since it answers the insurance question before a buyer’s lender raises it during escrow and can prevent a deal from stalling at the last minute.
For current owners with no plans to sell soon, the calculation is simpler. A renewal notice does not usually arrive with much warning, so having a clear picture of your wiring status now means you are choosing the timeline for this work instead of having it chosen for you.
Getting Ahead of It in Pasadena
Because Pasadena runs its own municipal utility, Pasadena Water and Power, service upgrades and rewiring projects here follow the city’s own connection and permitting process rather than a private utility’s. A local electrician who does this work regularly already knows that process, which keeps a rewiring project from stalling on paperwork.
If you own a historic home in Pasadena and are not sure where your wiring stands, the safest first step is a straightforward inspection, not a guess based on how old the house looks. Blue Moon Electrical’s licensed Pasadena electricians handle knob and tube identification, phased rewiring, and the documentation your insurer will actually accept, all while protecting the original character of the home.
