IQ+ Report: Irvine Home Builders Get Smarter

Third-party inspector Scott Johnson conducts performance tests to check duct leakage (top), supply register airflow (middle), and static pressure (bottom).

This IQ+ house, located in Harvard Square, one of Irvine's many villages, was built by California Pacific Homes.

Before the program began, Duct Blaster, blower door, and flow hood tests conducted in some new area homes revealed air leakage in ductwork that ranged from an acceptable 10% to as much as 80%. In some rooms there was little or no air flow.

A Slow Start

At first, builder interest in the program was low. This was partly because the once-slow housing market in Irvine suddenly exploded. IQ+, designed to help quality contractors differentiate themselves in the market, was of little use when builders could sell homes as quickly as they could construct them. In addition, budget constraints prevented the city from marketing the plan as it hoped to do. Virtually all of the homes built in Irvine are constructed by eight to ten production home builders. To make matters worse, at first only one company--California Pacific Homes Incorporated (Cal Pac)--participated in the program.

By early 1998, just 53 homes had been certified by a city-approved third party inspector, as required under IQ+. Meanwhile, 662 certificates of occupancy and 986 new permits were issued in Irvine for 1997, a significant increase from 1996 figures.

IQ+ Takes Off

In June, Cal Pac met with Irvine city staff, the California Energy Commission, and third party inspector Scott Johnson of the firm Action Now to explore construction alternatives that could further increase energy efficiency. In some cases, simple changes to design and building practices were suggested that made HVAC systems work more efficiently.

In one model, for example, a soffit above a refrigerator was redesigned to allow room for a duct to turn and deliver air to the kitchen. The original plan had left little or no room for the duct in the cavity, causing a bend that drastically cut off air flow. The solution to the problem--extending the soffit--had insignificant architectural impact, required very little additional material, and substantially enhanced the performance of the home by creating better air flow in the kitchen.

There were other program refinements. Originally, builders were required to submit HVAC plans to the city at the same time as they submitted their building plans. Now the required drawings showing register locations, duct lengths, connections, and air flows are submitted directly to the independent inspector, a change that allows direct communication between inspectors and contractors. Also, Irvine planned to check the air flow in many, if not all, the homes to begin with. Now thorough tests are conducted in the models, and any problems identified there are addressed at the production stage.

Another program modification was that IQ+ originally required two return air grilles for all two-story homes, with the grille on the first story located within 3 ft of the first floor. Today, the 3-ft height requirement is waived at the builder's request, because it has been determined that this protocol does not greatly improve system performance and may not be cost-effective for certain house designs.

A+ Performance

Impressed by these results, Cal Pac is increasing its superintendents' and subcontractors' training, and has embraced performance testing. It says that energy efficiency will play an increasingly important role in both the construction and the marketing of its new homes.

The second phase of IQ+ should begin in early 1999. Additional subcontractors will be trained in the latest energy efficiency techniques, and the program's requirements will be expanded to include additional elements (such as ducts in conditioned space) consistent with a systems approach to home design. This, according to IQ+
program manager Shawn Thompson, "will provide the Irvine community with some of the most comfortable, energy-efficient production homes in the nation."

For more information on the IQ+ program, contact Shawn Thompson at the city of Irvine. Tel:(949)724-6358.
 

Home Energy can be reached at: contact@homeenergy.org
Home Energy magazine -- Please read our Copyright Notice