design process study for the demonstration homes - Architectural ...

4.0 Recommendations for the Energy Commission’s ZENHome Program
4.1. Cost and features
The net incremental cost for ZEH features over a base Title 24 home in California ranged
from $8,000 to $15,000, depending on the aggressiveness of the rebates from the utility
service territories. For example, in investor-owned utility territories where the state
incentive is only $2.60/watt for a PV buydown (compared to the $3.50/watt incentive
from SMUD or the $4.00/watt incentive from Roseville Electric), it would be more
expensive to build ZEHs.
The net cost to achieve the PIER Utility-focused Market Model ZENHomes will depend
on the rebates available at both the state and federal levels during project term (2006–
2008), but will be similar to the incremental cost quoted from the ZEH case studies. The
features required to achieve ZENHome goals are similar to ZEH features as well.
It is important for the ZENHome project team (Architectural Energy Corporation,
Southern California Edison, ConSol, Geltz Communications, ConsumerPowerline, and the
PV manufacturer) to work to acquire all possible rebates and incentives to minimize the
cost of building ZENHomes to the builder and homeowner. It also is important to identify
and attempt to quantify benefits gained from media coverage, modifications in the
entitlement processes, and mortgage advantages from significantly lower energy bills.
4.2. Facilitate involvement of local government
Local government participants need to be on-board early in the Utility-focused Market
Model for ZENHomes project. Some of the energy efficiency features (e.g., DOW T-Mass
walls, buried ducts, OASYS evaporative cooler, etc.) could require significant discussions
with the local building department, resulting in project delays. The ZENHome team must
work proactively with building departments to facilitate understanding of the features
and minimize delays and, if possible, make these projects highly visible within the local
government. Delays may be avoided and plan reviews may occur faster if the building
department and city government are included as an integral part of the project.
4.3. 1-kW requirement
One of the goals for the PIER ZENHome Program is to achieve 1 kW peak demand in
each home. This goal will be studied in the Utility-focused Market Model for ZENHome
project. It is important to note that the ease with which the 1-kW goal can be met depends
on the size of the home. The 1-kW goal will be harder to achieve for larger homes and in
harsher climate zones. An in-depth discussion on the 1-kW issue and the effects of square
footage and climate zones will be provided in future deliverables.
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