Certifications

CASE STUDIES 2 of 2

Rating Zero-Energy Homes

Accountability Meets Marketing Claims

Client: R. Carter Scott, owner of Transformations, Inc.
Location: Homes at Coppersmith Way, Townsend, MA

Challenge/Business Need

There’s a lot of talk these days among construction professionals and realtors about "green building" and "zero-energy homes." A builder or developer can make this claim, but how does the buyer know for sure that they are receiving the stated value? Carter Scott is building zero energy homes--at no extra cost above that of a conventional home--creating positive cash flow from the start, and being truly low impact with near-zero greenhouse gas emissions.

CSG’s ROLE

CSG is an independent rater of green new construction, both single-family and multifamily residences. With a staff of building science experts and top-notch raters, CSG eliminates the uncertainty of building green by offering:

• Certification services
• HERS ratings (Home Energy Rating System)

CSG provides a flexible menu of services for new construction and information about available rebates and incentives. For Carter Scott’s project this meant that CSG was a part of their larger, collaborative team of energy experts, builders, and designers. Carter Scott worked with CSG to earn Earth Advantage certifications for four of his projects in 2009.

Strategy & goals

Using a whole-house (“house as a system”) approach, CSG promotes and administers a range of new construction programs and services. We work with energy program administrators and others to recruit, train, and enable builders and contractors to practice energy efficient and sustainable construction techniques in new single and multi-family homes.

Green building standards affect a project from plans to planting. CSG staff met with Carter Scott and reviewed his project goals and timelines to ensure the certification requirements were met.

Impact

One of the homes that earned green certification is Scott’s “Needham” Model, pictured above. This home was inexpensive to build, it costs dramatically less to operate, and has practically no greenhouse gas emissions. The immediate positive cash flow of choosing this zero-energy home is shown in the table below. Note that this does not even include all applicable federal tax credits, utility rebates, and incentives which make savings even greater.

The Needham compared with a typical code-built home
Description	Typical cost	Zero energy cost	Difference (approx)	Notes
Insulation	$8,000	$14,000	-$6,000
Framing		$900 extra	-$900	Additional cost to frame double wall for super insulation
Finish carpentry savings			$1,328	Window trim replaced by flaring of window well area
Windows	$4,342	$5,031	-$689	Triple pane low-e krypton gas filled
High efficiency heating/cooling	$17,000	$5,250	$11,750*	Ductless mini-splits for heating & cooling – extra downsizing possible because of added insulation
PV system	$33,000	$28,200	-$4,800	Rebates/tax credits lowered the cost of solar energy installation
Total construction cost difference*			$689	Nearly $700 saved by spending more on building shell which enables a lower HVAC system cost
Utility bills, monthly	$150	$30	$120	Operating cost savings about $1,400 annually
*Without PV would be a much higher construction cost savings, but then higher monthly utility bills

CSG Contacts

Robert Eckel, New England Regional Director
Caitriona Cooke, New Construction Program Manager