Construction activities, transportation to jobsites, and office operations are all major energy gobblers and creators of the greenhouse gas carbon dioxide (CO2), a driver of global warming. Building energy-efficient and sustainable homes, reducing jobsite waste and recycling, reducing company transportation and fuel use, and implementing greener office practices are key steps to reducing a building firm's environmental impact. But there's always something more that can be done, and purchasing carbon offsets through a reputable provider is one major way to mitigate the CO2 your firm creates.

Carbon offset purchases allow businesses and individuals to counteract the greenhouse gas emissions they create by funding green projects, such as renewable energy generation or forest carbon sequestration, being carried out by other businesses that would otherwise be unable to do so.

It's easier and less expensive than you might think. That's what custom builder Frank Dalene, president and CEO of Hamptons Luxury Homes (HLH) of Bridgehampton, N.Y., and founder of the Hamptons Green Alliance (HGA), discovered when he decided to further shrink HLH's carbon footprint by purchasing offsets.

Dalene and his partners had already reduced their firm's operational CO2 emissions as much as possible as part of their overarching goal of achieving carbon neutrality, in addition to building greener homes. As a founding member of the HGA and the builder of the organization's first net-zero energy demonstration home (read about it here), Dalene is serious about neutralizing the environmental impact of both his company and the homes it builds. Purchasing carbon offsets seemed a logical and beneficial way to cement HLH's leadership as a carbon-neutral business and to demonstrate to HGA members how offset purchases work.

Vague and unsubstantiated claims and other shady practices are common in the still-developing retail carbon offset market, so Dalene researched potential offset brokers thoroughly. He selected Verus Carbon Neutral, which is a member of the Chicago Climate Exchange (CCX)—a greenhouse gas cap and trade institution that requires third-party verification of the carbon reduction projects it registers. Verus purchases green commodities registered on CCX and sells them to clients to offset their carbon emissions. Once all the offsets generated by a specific project are purchased, the project is retired from the CCX so it can't be sold multiple times.

To determine a company's carbon footprint, Verus conducted an audit of the company's CO2 emissions based on three key factors:

1. the amount and type of fossil fuel the company burns;2. the amount of utility-supplied electricity it uses and how cleanly that electricity is generated;
3. and other emissions-producing activities such as business travel, employee commutes, business waste, and recycling.

Once these elements are calculated, they're converted into metric tons to represent a company's carbon footprint. Verus then offers clients a menu of options for offsetting the emissions. Clients may choose to offset from 10 percent to 100 percent of their emissions and may select a local or a foreign offset project.