One subject being addressed intensively by the inaugural edition of the Connecticut Zero Energy Challenge is how luxury-home builders can push relatively large homes – those exceeding, say, 3,500 sq. ft. – toward high levels of energy efficiency and market them accordingly.

The Zero Energy Challenge, which officially launched in May 2009 and is scheduled to end December 1, includes among its 18 entries nine projects larger than 3,500 sq. ft. Many of these properties, not surprisingly, are high-end homes that may not achieve net-zero-energy performance, but are nonetheless aiming for energy efficiency significantly above what building to code would deliver when evaluated using the Residential Energy Services Network’s HERS Index.

A luxury Challenge project that recently caught the attention of the Hartford Courant, though, is a home that measures 2,848 sq. ft. Though modest by luxury-home standards, the house nonetheless carries an $897,500 listing price. One objective in building this four-bedroom/2.5-bath single-family, says William Freeman, of Celebration Development Group, was to create a buyer-friendly blend of high-end finishes and amenities, and superior energy performance.

Awaiting HERS results

After December 1, each home competing in the Challenge will be evaluated using the HERS Index. The results will be announced on December 8, with the three lowest HERS ratings earning prize money: $15,000 for first place, $10,000 for second, $5,000 for third. Enhancing the challenge for Celebration Development’s house, which is part of a 14-home subdivision in Essex called Heron Pond, is that the house is not optimally situated for solar power. To keep its HERS score as low as possible, it will rely largely on shell insulation – R-19 foundation walls, R-24.5 exterior walls, and R-42.3 frame floors and flat and vaulted ceilings – and a ground-source heat pump system for heating and cooling.

Celebration calculates the home’s HVAC operating and water heating costs will come to $1,443 annually, about $3,890 (or 72%) less than it would cost to operate a house of similar size and configuration that was built to code.

HERS results for the Heron Pond house have not yet been posted, but Justin Lindenmayer, program administrator for residential new construction at Connecticut Light & Power, which administers the competition through the CT Energy Efficiency Fund program, told the Courant that among the homes reporting HERS results so far, “we’ve had one home that’s below zero, we’ve had a few in the 5-15 range, and more in the 20-30 range.”