RA4.5                              Other Measures

RA4.5.1 Controlled Ventilation Crawlspace (CVC)

Drainage. Proper enforcement of site engineering and drainage, and emphasis on the importance of proper landscaping techniques in maintaining adequate site drainage, is critical.

Ground Water And Soils. Local ground water tables at maximum winter recharge elevation should be below the lowest excavated site foundation elevations. Sites that are well drained and that do not have surface water problems are generally good candidates for this stem-wall insulation strategy. However, the eligibility of this alternative insulating technique is entirely at the enforcement agency officials' discretion. Where disagreements exist, it is incumbent upon the applicant to provide sufficient proof that site drainage strategies (e.g., perimeter drainage techniques) will prevent potential problems.

Ventilation. All crawl space vents must have automatic vent dampers to receive this credit. Automatic vent dampers must be shown on the building plans and installed. The dampers should be temperature actuated to be fully closed at approximately 40°F and fully open at approximately 70°F. Cross ventilation consisting of the required vent area reasonably distributed between opposing foundation walls is required.

Foam Plastic Insulating Materials. Foam plastic insulating materials must be shown on the plans and installed when complying with the following requirements:

Fire Safety—CBC Section 719. Products shall be protected as specified. Certain products have been approved for exposed use in under floor areas by testing and/or listing.

Direct Earth Contact—Foam plastic insulation used for crawl-space insulation having direct earth contact shall be a closed cell water resistant material and meet the slab-edge insulation requirements for water absorption and water vapor transmission rate specified in the mandatory measures.

Vapor Retarder: A Class I or Class II vapor retarder shall be placed over the earth floor of the crawl space to reduce moisture entry and protect insulation from condensation, as specified in the exception to Section 150.0(d).

RA4.5.2 Sunspace

The installation of a sunspace can be a very beneficial energy features in many parts of California.  However, if orientation fenestration area or fenestration performance values are installed that to not match compliance documentation then the performance of a sunroom can have significant negative energy impacts.  Another critical components of sunroom is ventilation. Sunrooms must have the ability to vent to the outside and to provide airflow to the rest of the house.  If any of these components are not present in the actual installation the performance documentation should be reviewed carefully.

RA4.5.3 Multiple Orientations Compliance

When all orientations are used to document compliance as allowed under Section 150.1(c)4 EXCEPTION, the following guidelines shall be meet.  Compliance for multi-family or subdivisions that is based upon multiple orientation the annual energy consumption for each specific design (including the reverse images of that design) must be calculated in each of the four cardinal orientations: true north, true east, true south and true west. With this option, a dwelling unit plan must be modeled using the identical combination of energy features and levels in each orientation, and must comply with the energy budget in each case. All of the orientation must either use the reversed plan or the original/standard to demonstrate compliance.

If the dwelling unit have unique designs or energy features the dwelling unit plan must be modeled using the worst-case condition for the energy features that the plan may contain (e.g. highest glazing percentage, least overhangs, largest wall surface area, and with exterior walls instead of party walls if applicable). See Reference Residential Appendix RA 2.6.1 for information that describes how to determine when a dwelling is considered to be a unique model. Each unique dwelling plan must also be modeled separately for each unique floor level. The option of modeling each individual dwelling unit, with its unique characteristics separately according to its actual orientation is always an acceptable alternative.