Old House Wiring: Knob-And-Tube--No More

By: Mark Clement , Contributing Writer
In: Old Houses, Old House Construction, Old House Terminology, Old House Musings

Last week’s blog outlined the joys of upgrading knob-and-tube wiring–and how to NOT upgrade it. Well, if your house is like mine you’ll upgrade more than the wire coming out of the breaker panel. You’ll probably upgrade the panel too, known in the industry as a “heavy-up.”

Most older homes I’ve renovated have a baseline electrical “service” of 100 amps. (service = the amount of juice, aka “amps,” the breaker panel / fuse box can disseminate throughout the house). A hundred amps will get you by, but most modern homes are wired with 200 amp service to meet modern electrical demands like flat screen TVs, microwaves, teenagers, etc. and still have enough space in reserve to handle and add-ons like garage shops, small additions, outdoor devices, yet-to-be invented gadgetry, and so on.

Old House Wiring: Heavy-Up

Part and parcel with a heavy-up is usually a “switch and plug” which means all your electrical devices–i.e. plugs, light switches–should be upgraded as well. This is for two reasons.

  1. Because a modern device is grounded
  2. They meet code, notably GFCI (ground fault circuit interrupter) in the presence of water/moisture as you’ll find outdoors, and in kitchens and baths

And, if your house is like mine, there’s a third feature modern devices deliver: they actually turn the light on.


Many modern, bright white plastic dealio devices, however, just harsh an old house’s mellow. That’s when you want to go old school and get some vintage devices with modern guts.

Old House Wiring: Updating with a Whole-House Surge-Supressor

I would also recommend installing a whole-house surge-suppressor at the same time. And by “installing” I mean have your electrician do it. This is no DIY job. You can still use localized power-strips but the whole-house will really take the bite out of a power surge, technically called “transience.” In other words, a lightning strike is a power surge but what the unit is really doing is evening out more subtle fluctuations (up and down) of the current feeding your home. See, everything from your MacBook to your coffee maker has a microprocessor in it that requires very even current. Older systems were never designed to manage transience. The email you save could be your own (or this blog!!!)

And not only don’t you ever have to think about it again after its installed, it protects everything in the house (like your dryer, appliances, etc.) that usually don’t have a power strip.

Old House Wiring: Preparing for Modern Life

Moreover, modern life in an old house often means a home office of some sort or media room so I take this opportunity to not only add plugs every twelve feet, per code (note: the intent of the electrical code here is that the distance is no more than 6 feet from a device like a lamp, TV, etc and the code assumes the item has a 6 foot cord.

Long story short, that usually translates to a plug on the wall every 12 feet…just trying to give you the low-down know what I’m sayin’–okay, segue over) but to upgrade them from duals (2 outlets) to quads (4 outlets) as appropriate. The reality of modern life is we plug more things in than Frank Lloyd Wright even dreamed would exist, nevermind planned for.

That’s our job as new old house owners.