Saving Money With a Home Energy Audit

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Although my personal home is only eight years old, I’ve known for a while that it’s not as energy-efficient as it could be. My heating bills aren’t outrageous, but they could be lower. Also, as you walk around my house, you can feel the cold spots. My son’s room is the coldest bedroom in the house – why? One spot of floor in the breakfast nook is much colder than the others – what can I do about it?

I decided to get an energy audit done of my house, and my two rental properties. Some utilities provide energy audits for free, but my local utility has a very long waiting list for such services, so I hired a contractor from Massachusetts instead. The contractor is giving me a deal since he is doing all three properties.

Energy auditors use a variety of high-tech tools to examine a building for cold spots, and have a contracting background so they know where to look, what products will work, and how to install those products, to make the property more efficient. However, I’m going to handle the installation myself, with advice from the contractors, Gene Williams and Greg Bogosian of eSave.

The first step in the audit is finding gaps between the “conditioned area” (where you are heating) and the “unconditioned area” (everywhere else) of the home. My unconditioned areas are the garage, the attic, the bulkhead from the basement, and of course the outside. The primary tools used here are a smoke pen, a blower door, and an infrared scanner.

What are these things?

A blower door is an attachment that fits into one of your doors to the outside. It has a hole in the middle, into which the auditors attach a fan, blowing outside. By sucking air out of your home, the blower door enhances drafts coming in through other areas.

Here’s an example. Let’s say your windows are not properly sealed, allowing drafts. Cold air comes in through the gaps because there is a pressure differential between the inside and the outside. Put another way, air comes in through one gap to replace air that was lost through some other gap. The blower door, by pushing a lot of air out the front door, lowers air pressure inside the home. More air will now come in through the drafts.

The smoke pen looks like a little bicycle pump. When the pump handle is pushed, the smoke pen emits “smoke” that is non-toxic and does not leave a residue. The smoke moves with the airflow, thus showing where air is coming from. A strong stream away from a spot shows a source of air coming in.

Gene and Greg did not have their infrared scanner with them, but they’ll be bringing that next week. The infrared scanner shows cold spots in walls, ceilings and floors. These cold spots indicate either hidden gaps (you can’t see them, but they’re letting cold air in) or places where insulation has not been added.

My Very Own ATM

Gene and Greg went through the house, finding gaps everywhere. Most of my windows have gaps around the installation, letting drafts in. There are also drafts around holes cut for wires, pipes, and hot air ducts.

As I walked around with the auditors, I started thinking of my house as an ATM machine. Unfortunately, this ATM is not dispensing money to me, but to Mother Nature. Every one of those little gaps is like a slot into which Mother Nature (or, if you prefer, Northern Utilities) inserts a card every couple of days and retrieves another $20.

Besides a bazillion gaps, I also found out my attic is insulated to R-30 only, where it really should be R-40. I’m going to add insulation there. I will also make sure the attic joists are covered with insulation. Since wood conducts heat pretty well, every uncovered joist is another ATM slot.

The 80% Rule

The 80% rule is also known as the law of diminishing returns. Obviously all this insulating and sealing is going to cost me money. Fortunately, these are one-time expenses, whereas I have to heat my home every year. However, for each new energy-saving measure, I have to compare the one-time cost to the lifetime energy savings. If something costs $500 and will only reduce my energy cost by $20 per year, maybe I shouldn’t do it.

They call it the 80% rule because the first 80% of energy-efficiency measures will cost about the same as the last 20%. Therefore, I’ll probably only do that first 80%.

There’s still some more auditing work to be done, with the infrared scanner I mentioned before. After that, I’ll unleash Gene and Greg on my rental properties. Those buildings are much older and I know they are much less efficient than my home. I can’t wait to see the results, and I’ll let you know how things turn out.

Note By BiggerPockets: These are opinions written by the author and do not necessarily represent the opinions of BiggerPockets.