Old Housing Stock · 2026-08-20
A huge share of South Jersey's rental stock predates 1950, which means a huge share of it was born with knob and tube wiring. Some of it is still in the walls. Here is how to find out, what actually matters for a rental, and when the rewire is worth it, from a team that owns and manages this exact housing.
Knob and tube is the original residential wiring system: individual hot and neutral wires run separately through ceramic knobs and tubes, with no ground wire anywhere. Look in the basement ceiling and the attic. If you see single cloth-covered wires threaded through white ceramic cylinders, you have it, at least in part.
Most old houses are hybrids. Kitchens and bathrooms got rewired in past renovations while bedroom circuits and ceiling fixtures kept the original runs. The panel can look modern while half the branches behind it are ninety years old, which is why a panel swap alone tells you nothing about what is in the walls.
Three reasons. Insurance first: many carriers refuse to write or renew policies on properties with active knob and tube, and the ones that will often surcharge or demand remediation on a timeline. For a landlord, an uninsurable building is not a building, so this is usually the forcing issue.
Second, inspections. Municipal rental inspections and Section 8 housing inspections both flag exposed, damaged, or amateur-spliced wiring. Intact knob and tube behind plaster often passes; hacked-up junctions in the basement do not.
Third, modern load. The system was designed for a few lightbulbs, not window air conditioners and space heaters on every circuit. The real fire risk shows up where old wire meets modern demand, especially where blown-in insulation now buries wire that was designed to cool in open air.
Get a real assessment from a licensed electrician, not a drive-by quote. You want a circuit map: which runs are original, which are buried in insulation, which junctions are suspect. Priorities come in this order: anything buried in insulation, anything spliced badly, high-load circuits, then everything else.
A full rewire on a typical South Jersey single is a five-figure job, and on a rental we usually phase it: correct the dangerous conditions immediately, then rewire room by room at tenant turns when the walls are accessible and the unit is empty. That converts one huge capital hit into planned turn-cost line items.
What we do not recommend is pretending. Disclosure obligations aside, an insurance non-renewal letter or a failed inspection always costs more than the assessment you skipped.
Free Owner Consult
We own and manage pre-war housing across six counties. Bring us the address and we will tell you what the electrical reality is likely to be and how we would phase the fix.
Or use the form on our For Owners page.