Intelligent Weatherization

Billing Analysis Tool

Billing Analysis Data Collection Tool

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The billing analysis tool provides a standard means of collecting, visualizing, and analyzing a client’s pre-weatherization energy consumption.  This tool is designed to be used for clients who have metered utilities.  This tool is not intended to analyze bulk fuels such as LP gas, fuel oil, or wood.

Knowing how much energy a home is consuming before an audit is very useful.  If the auditor knows the house is not using much energy before visiting the house, the auditor knows to focus more on health & safety, durability, and comfort issues.  If the auditor knows the house is consuming vast amounts of energy the auditor can keep a wary eye out for energy waste.

Data Collection

The fields at the top of the tool are for standard client contact information (name, address, phone number) as well as information specific to the client’s utilities (natural gas and/or electric utilities and account numbers).  Finally, there is a field to document who the auditor(s) is.

The first two red bordered cells that must be used are the county and primary fuel cells on the right side of the tool.  The county cell is a drop down list of all the counties in Indiana.  Entering the proper county is important for the tool to properly calculate the house’s Home Heating Index (HHI).  The primary fuel cell has two choices, natural gas and electricity.  Whichever fuel is chosen is the fuel used to calculate the house’s HHI.

The monthly consumption values need to be entered for the primary fuel.  Entering consumption data for the secondary metered fuel is optional.  Often billing periods for a utility company do not fall at the beginning or end of a given month.  With partial month billing periods, put the consumption data in whichever month had the majority of the days in the billing period.  For example, if a billing period goes from 9/10 to 10/11, most of that particular billing period was in September.  In that example, the consumption for that billing period would be entered into the September cell despite ending in October.  Entering the house’s square footage is optional, similar to a secondary metered fuel.  If the house’s square footage is entered, the tool will use it to calculate the house’s HHI.


After the monthly consumption data has been entered, the energy values are converted to btus and plotted at the bottom of the page.  Natural gas consumption is shown in red and electric consumption is shown in blue.


Chart analysis – The graph of monthly consumption can be used to help identify patterns of high consumption.  Where more btus are shown indicate when & with which fuel the high consumption occurs.  When there is greater consumption, the potential for savings is also greater.

Home Heating Index – There are two ways to use the Home Heating Index with this tool.  The first method is if the square footage of the house is known.  Some real estate websites or local tax assessor websites may have a house’s square footage information posted and available to be used prior to visiting a house.  With the actual square footage of the house entered into the tool, a HHI can be calculated specific to the house.  The HHI provides valuable insight about how efficiently or inefficiently the house is performing.  HHIs under four btus/sqft*HDD indicate a very efficient home.  A HHI 18 or greater indicates an inefficient use of energy with lots of savings opportunities.  The average pre-weatherization HHI for Indiana weatherization is 12.

The tool is also useful if the house square footage isn’t known prior to the audit.  If the square footage of the home isn’t known, that cell can be left empty.  Approximate HHIs are automatically calculated for several common dwelling sizes.  Other information can be used to make the approximate HHIs more useful.  For example, most single wide mobile homes are smaller than 1000 sqft.  Most site built homes are also larger than 800 sqft.  Many neighborhoods have typical home sizes.  Knowing where a house is located can help improve a rough guess of how big the house may be.