Zero Carbon ® Client Case Studies

Homeowner earns 46% return on investment by cutting carbon footprint 38%.

The first client of David Green’s Zero Carbon® consulting practice, David Sguazzin, has cut the carbon footprint of his modest home on Long Island, NY by approximately 4 tons of carbon dioxide per year and is saving over $1,100 per year on heating and electric bills. David Sguazzin is earning a 46% return on his investments in insulation, air sealing and triple-glazed windows. The triple-glazed windows were made by David Sguazzin and fitted to the inside of his existing single-pane windows using a technique pioneered by David Green on his own home. 

Before engaging Zero Carbon® LLC, the approximately 1,000 square foot, single-story house’s heating and electric bills were about $3,500 per year. Today, they are about $2,400 per year saving David Sguazzin $1,100 per year.  The total investment was about $1,300 in materials. The fee paid to Zero Carbon® LLC was 1x the annual savings on the bills or $1,100. The 46% return on investment includes the fee.

“Working with David Green was an absolute pleasure, he guided me through the process with his experience in lowering my energy expenses and my overall carbon footprint.” Said David Sguazzin.

David Green said, “If every household in the U.S. did what David Sguazzin has done, the US would more than reach its goals under the Paris Climate Treaty. And it could do it within a year. Every household would be better off by over $1,000 a year. Each year, every year and forever. This would be a $300 billion dollar economic stimulus to the U.S. economy every year. Using the standard rate of 8.34 jobs per million dollars of construction spending, this would create 2.5 million new jobs every year, just what we need to pull us out of this recession.”

If you live in Massachusetts, MassSave would have paid for almost all of David’s insulation program and would have installed the insulation for him.

On David Green’s own home, the return on investment in a more comprehensive program of energy reduction, heat pumps and solar panels that cut the house’s carbon footprint and utility bills to zero, was 15%. 

David Green’s “fab four” recipe for making money by cutting your carbon footprint has now been proven on houses ranging from 1,000 square feet to 5,400 square feet.

You can read more about the “fab four” by visiting where you can watch a 45-minute webinar, download the slides used in the webinar and download written Q&A from prior webinars, all for free.

David Green can be contacted at

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