Your house loses heat in a similar way to your body. Imagine that you’re preparing for a walk on a cold, windy day. You’ll need a sweater to be warm enough, but the wind will go right through your sweater so you put on a windbreaker too.

Think of the thick sweater you’re wearing under your shell or windbreaker as insulation. In the nerdy building science world we call it the “thermal boundary”. It’s purpose is to trap heat near your body. Your house’s thermal boundary is the insulation that you have in your walls and attic. Sometimes this is fiberglass, cellulose, foam, mineral wool, or in some in older houses just newspapers. The type of insulation in your home may depend on a number of factors, including when your home was built. Some older homes have no insulation at all.

Think of your windbreaker as the air barrier. It stops the wind from robbing the heat your body worked so hard to produce. Now, imagine that your windbreaker is full of holes. It will feel drafty and uncomfortable especially where the holes are. The air barrier in your house stops the heat from passing through the thermal boundary and escaping to the outside. The windbreaker (air sealing) in your house can be made of many materials: sheetrock, plastic, paper, as well as some very green and high tech air barriers that allow water vapor to pass through but very little air to escape. When we do audits we can actually “see” air and often find many holes in the air barrier in a home; this holds true for historic 200 year old homes as well as brand new homes. 

The audit is the starting point for making any informed decisions regarding home performance and energy efficiency. An audit takes a holistic approach to looking at your house’s efficiency. It is the point at which we collect all the interrelated data the house has to offer and synthesize it into a format that helps us identify the ways that the various pieces of the house are working together or are working to create problems for the house and you; with it we can have a complete and comprehensive picture of how it can be improved. We can predict how adding something or taking something away will have a ripple effect through the whole system of your house.

We look at every assembly of the house from the basement to the attic. We evaluate the efficiency of heating and cooling systems, electrical efficiencies, indoor air quality, ventilation as well as moisture and mold issues. We look at windows; obscure assemblies and things called “thermal bypasses” that you might not expect would be sources of heat loss. These are areas like house connections with chimneys, porches and garages. From this list of observations come recommendations on improvements.

The information we are able to gather in these audits is incredibly important to how we think about your home, which is why Lewis Creek Company includes a free energy audit with each renovation – the information is that critical.

Walk through the process with our Energy Audit checklist.

What happens after the energy audit? Find out in our blog post “After Your Energy Audit: Projects and Cost Savings”.

Updated 1.10.18