Remember SnackWells? Americans went crazy when these tasty low-fat products first came out. But along came the SnackWell effect, which Wikipedia defines as:
A phenomenon that states that dieters will eat more low-calorie cookies, such as SnackWells, than they otherwise would for normal cookies.
And so it goes with housing.
The Energy Information Association (EIA) is out with its most recent Residential Energy Consumption Survey (RECS). They brag,
U.S. homes built in 2000 and later consume ONLY (my emphasis) 2% more energy on average than homes built prior to 2000, despite being on average 30% larger.
The Business Insider reported housing-guru Robert Shiller’s response, saying:
…There’s technical progress in housing. So, new ones are better.
But the data that’s cited tells a tale of the SnackWell effect. My takeaway from that same data is that new may not necessarily be better.
When I do the scoring, seems like Existing Homes have more options and definitely come out ahead!
End Use |
New Homes |
Existing Homes |
Advantage? |
Space Heating |
Use 21% less (Advances in space heating and building envelope) |
Programs like Home Performance with ENERGY STAR often reduce total energy use by 15-20% |
Tie |
Water Heating |
Use 3% more |
Tie |
|
Air Conditioning |
Use 56% more More space to cool |
Existing Homes |
|
Appliances, Electronics, Lighting |
Use 18% more (More/bigger appliances, electronics, lighting) |
Option to install ENERGY STAR products |
Existing Homes |
Let’s talk again when the data on homes after 2010 is available. You’ll start to see carefully crafted homes that provide more quality and energy savings per square foot!
This information is also a sign why we need an alternative to the popular HERS Index for rating efficiency. HERS does not account for square footage (which leads to the SnackWell effect you see in table above). The rating system geared more towards existing homes is call Home Energy Score and takes square footage into account. No SnackWell Effect there!

