Mass Save

Mass Save Knob and Tube Inspection

Jesse Kuhlman Uncategorized

You have a home that is older, built prior to 1932 and you are looking to take advantage of the great offerings through the Mass Save program to insulate. Why are the Mass Save companies saying I need an electrical knob and tube inspection / sign off for this work?  What are the potential issues with knob and tube wiring? How much is this inspection going to cost me? How should I prepare for the inspection?  We’ll answer all these questions and more!

Knob and Tube Wiring

There are endless resources on the internet, including our own site, about knob and tube wiring so I’ll keep this section short. Click Here

Knob and tube wiring was used from the late 1800’s until roughly 1932 or so.  It’s an ungrounded wiring system that was run in open air, allowing it to dissipate heat.  Once insulation is packed around it, it can no longer dissipate heat effectively.  Simply put, insulation has the potential to cause the wiring to overheat, which could lead to an electrical fire.

It’s pretty easy to spot knob and tube wiring in open / unfinished basements as pictured below.

It’s also easy to spot it in open attic spaces in the picture below

Where it gets tricky.  Hidden knob and tube wiring?

In a lot of homes we inspect, the visible knob and tube that was once present in the basement has been removed.  Making it seem as though the house has none! This could have been done by a handy home owner, or an electrician being paid to conceal it.  Often times home inspectors will tell potential owners that the home is most likely clear of knob and tube wiring due to it “appearing” to have been removed.

If your home was built in the knob and tube era, with no visible knob and tube, a more in depth inspection will be necessary.

The knob and tube inspection

To perform a knob and tube inspection properly, almost all lights, switches and receptacles will need to be examined. This means removing plates and checking inside the electrical boxes to spot the knob and tube wiring.

When the electrician goes through the house he/she will be taking notes of where the knob and tube wiring is still active. Using these notes an estimate will be created and sent to the customer (you) via email for replacement of the knob and tube wiring. 

Do you have to replace the knob and tube wiring?  It needs to be replaced if you intend to get insulation. With active knob and tube wiring it will be impossible to get insulation.

Be wary of electricians who do not take the time to perform the inspection properly. If they only look in the basement and see no knob and tube, and proceed to sign off on it without looking at any switches / receptacles I would ask for a more throughout inspection.  You don’t want to take a chance insulating a house that may in fact have hidden active knob and tube wiring throughout.

Preparing of the inspection

There is little preparation from the customer stand point. The only things an electrician will need are as follows –

  • Access to the entire house. This is includes all rooms, bedrooms, basement, attic (if there is one)
  • Being OK with some power being turned off. If active knob and tube is found, the electrician will be turning that circuit off to see what else it connects to.  The power shouldn’t be off long.
  • Access to the electrical panel(s)
  • If you want to move furniture away from receptacles and switches this will speed up the inspection. If not, we are happy to do it.

That is really it. Having access to all parts of the house is the critical part.

How much does it cost?

Knob and tube inspections cost a flat rate of $250.00 per unit / house. This rate is set by the Mass Save Program.  For some customers, the inspection may actually be FREE.  This depends on where you live and what agreement your power company has with Mass Save.  At the time of writing this, Eversource customer’s knob and tube inspections are free.  The rumor is that National Grid may be doing this as well in the future. Fingers crossed!

With a multifamily home the cost is $250 per unit.  For example a three family will cost a total of $750.00

If you have to pay for your inspection out of pocket, the cost of the inspection will be refunded / applied to your insulation work. So it’s not as though you are losing that money.  Check with your Mass Save company for the exact details as these programs are ever evolving.

I have active knob and tube wiring.  I don’t want to replace it; do I still pay the inspection fee?

Yes unfortunately you still need to pay for the inspection regardless of if you want to move forward with replacement.  If you are fortunate to live an area with Eversource as your power company, this is a moot point.

If you decide down the road to replace the knob and tube wiring and get insulation, you would get that $250.00 inspection fee credited at that point. Again, check with your Mass Save company for details on this.

Knob and Tube Sign Off

The Mass Save company you are working with will have provided you with a sign off form.  This form is to be given to the electrician doing the inspection. If the home has no active knob and tube the electrician will sign the form stating so.  You will present this form to the Mass Save company you are working with which will get the ball rolling to the next step, insulation!

If you are in need of a knob and tube inspection, give us a call or shoot us an email. We are happy to help!  Click Here