California's Advanced Homes Program

September 01, 2010
September/October 2010
A version of this article appears in the September/October 2010 issue of Home Energy Magazine.
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California is slowly moving toward net zero energy construction, defined as building structures that produce as much energy on-site as they consume. The Long Term Energy Efficiency Strategic Plan of the California Public Utilities Commission (CPUC) states that starting in 2020, all new homes must be net zero energy. In addition, Assembly Bill 212, still going through the legislative process as of this writing, requires the California Energy Commission (CEC) to implement codes and standards to achieve this goal.

Steve Mann is a HERS rater, GreenPoint rater, LEED AP homes, Certified Energy Analyst, serial remodeler, and longtime software engineer. (April Wise Photos)
Although 2020 may sound like it’s many years in the future, it’s not that far away, and the CPUC and CEC realize that. Fortunately, they revise the state’s building energy code, commonly called Title 24, every three years. In addition, they work with the investor-owned utilities (IOUs), which provide most of the state’s power, to create incentive (rebate) programs that help promote the state’s long-term goals. Coincidentally, the IOUs revise their incentive programs every three years as well.

The latest Title 24 revision went into effect in January 2010. It is approximately 15% more stringent than the previous code revision. The latest IOU incentive program for new residential construction started at the same time. The rebates start at 15% above the current Title 24 baseline.

The Baseline

For energy code purposes, California is divided into 16 climate zones. Each zone has baseline specifications. For example, in the mild coastal climate zone where I live, a residence must meet the following specifications in order for the builder to receive a permit:

  • Insulation. R-30 ceilings, R-13 walls, and R-19 raised floors
  • Roofing. Cool roofs on steep-sloped roofs that weigh 5 lb/ft2 or more
  • Fenestration. A maximum U-factor and a solar heat gain coefficient (SHGC) of 0.4, maximum total glazing area no more than 20% of the building’s surface area
  • Ducts. Minimum R-6 insulation, maximum 6% duct leakage
In addition to the climate zone-specific specifications, there are also some statewide mandatory requirements, such as ASHRAE 62.2 compliance for local exhaust and ventilation. Combine the mandatory and climate zone-specific requirements, and you get the Title 24 baseline for a particular building.

You can comply with the baseline in one of two ways. The first method, called the prescriptive approach, requires that you meet or exceed all the climate zone and statewide requirements. It’s essentially a checklist-based compliance. The second method, called the performance approach, uses state-certified modeling software to compare the performance of your building with that of a building of the same size built to the prescriptive specifications. With the performance approach, you can trade off certain requirements for others. For instance, you can skip duct testing and compensate by, perhaps, increasing the wall insulation to R-19. If the software says that trade-off results in a residence that uses less energy than the baseline building, your structure complies.

Note that my description of California’s energy code is somewhat simplified. As you might imagine, there are a variety of interesting twists, turns, and quirks. The complete residential code fills more than 1,000 pages. The nonresidential code is even larger.

CAHP Homes


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Figure 1.The CAHP incentive calculation graph.
 
Pacific Gas and Electric Company, Southern California Edison, Southern California Gas Company, and San Diego Gas and Electric currently offer the California Advanced Homes Program (CAHP), the official name of the IOU residential new-construction rebate program. It’s available for single-family and low- and high-rise multifamily new construction. As I’ve already mentioned, in order to participate, you first have to exceed the Title 24 baseline for the building’s climate zone by 15%. The incentive is calculated using the difference between the energy consumption of the baseline house and the modeled house.

Figure 1 shows the basic incentive calculation graph. At 15%, you receive $75 for every peak-demand kW you save, $0.43 for every kWh you save, and $1.72 for every therm you save. (The savings are calculated using an hourly simulation over 12 months that includes only space heating and cooling, indoor fans, water heating, and pumps.) The incentive increases linearly as your percentage over baseline increases. It peaks at $225 per saved peak-demand kW, $1.29 per saved kWh, and $5.14 per saved therm.


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Figure 2.The incentive worksheet for a moderately energy-efficient home.
 
Figure 2 shows the worksheet generated by EnergyPro, one of the CEC-certified Title 24 programs, for a house that exceeds the baseline by 16%. The base incentive is a little over $200, all from nonpeak reduced electricity demand (the house uses a heat pump, so there is no natural gas usage at all). That’s not much of a financial incentive to push your house 15% past the minimum energy code requirements.

Figure 3 shows the EnergyPro work sheet for a house that exceeds baseline by 56.7%. (This particular worksheet from EnergyPro shows the percentage better than Title 24 up to the 45% ceiling only.) At the top incentive rates, the base incentive is close to $4,500, a much more interesting number. There is nothing remarkable about this 5,200 ft2 house (other than its size). It has R-19 crawlspace floors, R-19 2 x 6 walls, an R-30 attic, and a window U-factor of 0.35 and an SHGC of 0.25. A 95% Munchkin boiler supplies heating via radiant tubing in 1½ inches of lightweight concrete. 13 SEER air conditioners provide cooling. A pair of 98% tankless water heaters heat the domestic hot water. The only diagnostic testing required to hit 57% is testing the R-6 ducts for leakage of less than 6%.

Interestingly, as you exceed the baseline by 45%, the per-unit incentives remain at the 45% rates, but the energy savings they are applied to don’t. Consequently, if this house exceeds the baseline by 75%, the incentive will be even larger than that shown in Figure 3.


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Figure 3.The incentive worksheet for a very energy-efficient home.
 

The Kickers

In addition to the base incentives, there are a variety of what are called kickers. Looking back at Figure 1, you’ll notice a vertical line in the middle of the graph with $1,000 written above it. That’s the first of six possible kickers:

NSHP (New Solar Homes Partnership). If you exceed the Title 24 baseline by at least 30%, reduce your cooling load by at least 30%, and install at least a 1kW PV system, you are entitled to a $1,000 bonus.

Energy Star. If you meet California Energy Star requirements, which are slightly different from national Energy Star requirements, you receive a bonus of 10% of your base incentive (the rebate calculated before any kickers). California Energy Star requires duct testing, quality insulation installation (QII) and thermal bypass inspections, and ACCA Manual J/S or equivalent system design and sizing. Inspections and testing must be done by a certified HERS rater.

Green home. If you successfully complete GreenPoint Rated or LEED for Homes certification, you receive a bonus of 10% of your base incentive.

Compact home. If the residence meets the LEED for Homes small-residence floor area thresholds, you receive a bonus of 15% of your base incentive.

PV. For every DC-rated kW of PV that you install, you are entitled to an additional peak- demand incentive. For instance, if you are at 45% over the baseline and have a peak-demand reduction of 2 kW, you are entitled to $450 ($225 per kW). If you also install 2 kW of PV hardware, you are entitled to an additional $450.

Design Incentive. A project with at least ten housing units may qualify for a design team charette incentive of 50% of the cost, up to $5,000.

The PV incentives are all in addition to the ongoing California NSHP rebate program, which currently pays about $2.50 per installed watt for new construction and $3.30 per watt for new low-income housing.


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Figure 4. The kicker worksheet for a very energy-efficient home.
 
Figure 4 shows the bottom of the incentive calculation work sheet, the kicker section, for the 56.7% over baseline house shown in Figure 3. The kickers include a 2kW PV system and Energy Star and green home incentives, increasing the total payout to $6,800. Clearly that’s not enough extra money to pay for Energy Star and, say, a LEED for Homes certification, but it makes the equation more attractive. With a larger PV system, which is not uncommon, the incentive could reach close to $10,000.

The previous IOU incentive programs, which expired in December 2009, provided two types of payment. Houses that exceeded Title 24 by 15% could get up to $500. Houses that exceeded Title 24 by 35% could get up to $2,000. There were no program rewards for consumption reductions (modeled or otherwise), no rewards for installing PV systems, no rewards for green certifications or smaller homes. The CAHP will undoubtedly have its problems, but it certainly helps nudge builders toward net zero energy building.

The Process

It’s relatively easy to participate in the CAHP. First, the designer, architect, or builder has to have the Title 24 prepared by a Certified Energy Plans Examiner (CEPE) or a Certified Energy Analyst (CEA). These are both California-specific energy consultant certifications administered by the California Association of Building Energy Consultants (CABEC). CEPEs and CEAs are specially trained in Title 24 requirements and use of the California-approved modeling software.

If it looks as though the project will meet the program requirements, an application has to be submitted, prior to drywall installation, to an IOU that provides service to the building’s location. The application includes, among other things, the Title 24 calculations, a set of building plans, and a two-page application. Each IOU may require additional documentation.

Prior to drywall installation, a certified HERS rater must conduct an inspection for any energy-efficient features that contribute to the project’s percentage above Title 24 baseline and possible Energy Star or green certifications. These features may include obvious things like basic insulation levels, or a QII or thermal bypass inspection, but they may also include less obvious things like hot-water line insulation or buried-duct specifications.

Once the project is completed and the final building permit signed off, a certified HERS rater has to inspect the house for all the features that contributed to the Title 24 score, such as window specifications, glazing locations and sizes, mechanical equipment, duct testing, and so on. In addition, the HERS rater may need to verify the installation and operation of a PV system. HERS raters also need to collect installation certificates from various trades, such as insulation and HVAC, and finally, enter all their findings in an online database that is administered by the state’s HERS providers. Once all that is done, the utilities pay out the incentive.

Impact

There’s quite a gap between today’s building practices—not just in California—and a goal of net zero energy new construction by 2020. California’s latest IOU incentive programs will certainly help achieve that goal. Although the dollar amounts aren’t large, they should have an impact on home building in the state. There are separate programs in place and being legislated, at both the state and federal levels, to address the issue of existing homes, another part of the problem. Hopefully with the combination of all these efforts we can really cut down on our energy consumption.

 

For more information:

Steve Mann can be reached at steve@green-mann.com.
For more information about EnergyPro, visit www.EnergySoft.com.
For more information about the CAHP program, visit www.californiaadvancedhomes.com.
For more information about CABEC, visit www.cabec.org.

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