House Shopping: Amp it Up?

Do I need that 200-amp service?

A few months ago, I inspected a small 1998 townhouse in Richmond Hill with a 200-amp service. This was way more power than needed so my “high risk” radar went up. Oversized electric services are sometimes related to a history of electric heating, either baseboard or electric furnace. Fortunately, a neighbour was involved in the inspection and could confirm that his townhouse also had 200-amp service, and he knew it had been installed by the builder. There was no history of electric heating.  It’s possible that everyone in the townhouses was sold an upgrade by the builder.


The picture above is of this panel in the townhouse. Not really doing any harm, but sort of a space-waster and not earning any payback on investment.

I also inspected two new (2016) homes in Aurora recently, and the owners had paid the builder for an upgrade to 200-amp service.

So how do you determine if you need the upgrade to 200-amp service?  One piece of advice NOT to run with is the CMHC blooper below:

This is from the currently posted CMHC document: What to Look for when buying a Home ( 

Electrical system—if you are buying an older home, find out if the electrical panel has been upgraded. If the service says 200 amps, it is an upgrade. A 60 or 100-amp panel has probably not been upgraded, and may not be enough to meet the electricity needs of your family.

In GTA terms where we don’t use electric heat any more, this is a blooper. There are two things wrong with this. Firstly, 100 amps is the most common service size, and is adequate for most homes, even new homes that may be around the 3000-sq. ft. size.  and most old homes that are “upgraded”. Secondly, the panel rating alone is a poor indicator of total service size and electrical wiring upgrade status in an older home. It is true that a 60-amp service is no longer considered acceptable.

How do you know if you need the 200-amp upgrade? Simple answer for the new house is you don’t. You may want 200-amp but you don’t need it. If a builder is offering the house with 100-amp service, then it has already been determined that 100-amp is adequate for the house as-built along with a few extra circuit spaces for future consideration as required by code. If the house needs more than a 100-amp service based on the quantity and type of circuits, then it won’t be an option, the builder will simply install the correct size. If electrical loads are added on top of the original builder installations, then at some point the 100-amp capability may be exceeded. Typical additions that may put the 100-amp capability at risk are 240 volt ranges, driers, hot tubs, saunas. To determine when the 100-amp capability is exceeded you need an electrician to do the calculations for you. That is one reason why any significant electrical additions should be done by a qualified electrician.

So, if you don’t have any plans of adding electrical load to your new castle then stick with what the builder is offering as the base model. If you are planning significant addition of electrical loads such as fully finishing the basement with a kitchen and laundry, then ask an electrician to do some calculations for you, or just lay out the $2000-$3000 for the upgrade. If you have an older home that has had many electrical additions to the original circuits provided by the builder, then you may need an electrician to review the service size to see if it is adequate.  p.s interested to know what folks are paying the builder for this upgrade. The $2-3K is my best estimate now!

by Keith Tripp, January 2017