The Energy Formula
HOW DOES YOUR BUILDING STACK UP TO OTHERS?
In my opinion, the only universal metric is one that encompasses all your energy use, Gas + Electric, for example, divided by the Heated Square Footage, to get: HOW MANY DOLLARS / SQUARE FOOT / YEAR which can then be compared locally or nationally with a chance of a common understanding… what is a BTU anyway? haha.
Somewhere between $0.40/sf/yr and $2.50/sf/yr. Hopefully less because of weatherization.
All buildings should have a logical place for information to be stored and accessed. A website, a folder, a binder, anything. One of the most important pieces of information you can derive for a building is the Annual Operating Cost PER SQUARE FOOT. We should all be referring to buildings with the following metric: DOLLARS per SQUARE FOOT per YEAR
We should all be saving our energy bills somewhere. I don’t think enough people care about KWH or Therms or Gallons, and I don’t think we should be removing the connection fees, taxes, etc from the equations. Add up the TOTAL BILLS.
I think it makes the most sense to at first focus only on electricity and gas. If the home has renewable energy ignore that for now, it really doesn’t matter how much you generate if you are wasting. [Once these relatively expensive utilities are in the below $1.00/SF/year range we can try to add the water, sewer, trash, recycling, maintenance figures into the equation.]
Over the years we have been tracking energy use for many of our client’s. The most efficient homes we know of cost about $0.50 per square foot per year for a detached single family home. The worst homes are between $2.00 and $2.50 / sf / year in total energy.
There is a recurring condo design built in Raleigh where the third floor south facing units are using on average about $0.40-$0.50/HSF/year. The other units range from $0.50 to $0.70/HSF/year
The above downloadable document helps people figure out what portion of an energy bill is “plug-load” and what portion is heating or cooling.