PICKING THE LOW-HANGING FRUIT: IMPROVING THE ENERGY-EFFICIENCY OF EXISTING HOUSES

In 2009, a McKinsey report, “Unlocking Energy Efficiency in the US Economy,” identified $247 Billion in energy bills and 160 Megatons in CO2 emissions that could be saved by making only cost-effective (positive Net Present Value) improvements to existing homes in the US. That’s 160 Megatons of global-warming CO2 that are being emitted that can be eliminated by following some simple steps!  This post will discuss some steps that homeowners can take toward making these improvements happen.

One of the principle barriers the McKinsey report cited is a lack of awareness: “Homeowners typically do not understand their home’s energy consumption and are unaware of energy-saving measures.” Fortunately, many initiatives have been started to combat these gaps in homeowner education.

Awareness

Massachusetts start-up Sagewell has a very novel approach to increase awareness.  They take thermal images of houses a la Google Street view and post them to their website along with a rough analysis of the efficiency of the different house components for homeowners to view. Web sites like uplight.com* and Home Energy Saver are putting easy-to-use energy models in the hands of consumers.  Home energy audits, aided by government initiatives, are also becoming more prevalent.  And, of course, many of us have seen how we compare to our neighbors when we get our utility bills. One important theme for many of these initiatives is that they give users an incentive to act by showing them the estimated cost savings that could be achieved by making simple improvements.

Assessment

Once a homeowner obtains a list of improvements that could be applied to the home, s/he must next identify which component improvements make sense financially. To this end, the state of the building should first be diagnosed by doing a home energy assessment.

For those who prefer the do-it-yourself approach, the DOE has a good description of a home energy assessment that homeowners can perform themselves. By using an infrared thermometer, they can also determine the approximate R-value of their walls in minutes using this technique. But for those who don’t have the time or are planning a significant renovation, a professional home energy assessment is a good idea.

Analysis

To see which components should be improved, the homeowner can work with their builder or architect to model the existing building using an energy analysis software. For this process, the McKinsey report had another piece of advice: to consider “a building as a system that can be optimized within a specific site - rather than as a set of independent end-uses.” Ekotrope has designed HomeSEED for this exact purpose - optimizing the building as a system. Using HomeSEED, architects and builders can quickly find the best design improvements with accurate financial payback and carbon footprint information. This way, homeowners can make informed, measured decisions and build an improvement plan that fits their unique financial and environmental goals.

*Note: This article was updated in 2021 to reflect changes. The McKinsey Report referenced is no longer accessible via the domain provided at the time and we have updated the reference to EnergySavvy to redirect to Uplight.