Public Resources Code, Section 25402.1 (b) requires the California Energy Commission to establish a formal process for certification of compliance options of new products, materials, designs or procedures that can improve building efficiency levels established by the Building Energy Efficiency Standards. §10-109 of the Standards allows for the introduction of new calculation methods and measures which cannot be properly accounted for in the current approved compliance approaches. This process for approval of new products, materials, procedures, and calculation methods is called compliance options and helps to improve building efficiency levels set by the Standards.
The Energy Commission encourages the use of energy-saving techniques and designs for showing compliance with the standards. The compliance options process allows the Energy Commission to review and gather public input regarding the merits of new compliance techniques, products, materials, designs, or procedures to demonstrate compliance for newly constructed buildings, additions, and alterations to existing buildings. Approved compliance options are generally carried for use with the newer energy code when revisions are made to the standards and information regarding their use and eligibility and/or installation criteria are incorporated in compliance and reference manuals.
When the Energy Commission approves a new compliance option it is 'listed in the Special Cases section of the Energy Commission’s website based on the adoption year of the standards: www.energy.ca.gov/title24/2008standards/special_case_appliance/.
Compliance Overview
When compliance is being demonstrated with either the prescriptive or performance compliance paths, there are mandatory measures that must be installed. Minimum mandatory measures must be met regardless of the method of compliance being used. For example, a building may comply using performance computer modeling software with only a U-factor of U-0.41 insulation in a wood-framed attic roof, but a U-factor of at least U-0.031 must be installed because that is the mandatory minimum.
Standards Table 150.1-A
A. The prescriptive requirements are the simplest way to comply with the building envelope requirements but offer little flexibility. If each and every prescriptive requirement is met, the building envelope complies with the standards. The prescriptive envelope requirements are prescribed in §150.1 which include Table 150.1-A.
B. The prescriptive compliance approach consists of meeting specific requirements for each envelope component, plus meeting all minimum mandatory requirements, such as mandatory levels of insulation. Prescriptive requirements apply to:
1. roofs and ceilings,
2. exterior roofing products
3. exterior walls
4. floors
Fenestration must meet prescriptive efficiency values and have a maximum area of 20% of the window-to-wall ratio conditioned floor area (CFA). The efficiency values are specified for the maximum U-factor, maximum Solar Heat Gain Coefficient (SHGC) and maximum west facing area of 5% of the CFA. Specific requirements are made for glazing in doors, tubular skylights, non-tubular skylights, and chromatic type glazing (§150.1(c)3A).
The prescribed mandatory measures and prescriptive requirements affect the design and operation of the building. Mandatory measures, prescriptive requirements and operational schedules establish a minimum performance level which can be exceeded by other design measures and construction practices resulting in greater energy savings.
The performance approach is a more sophisticated compliance method and it offers greater design flexibility than the prescriptive approach. The performance approach may be used for any unique design element(s) that the user of compliance modeling software believes can contribute to the building’s overall energy use.
The performance approach allows for more energy tradeoffs between building features, such as increasing HVAC equipment efficiency in order to allow more fenestration area. See Section 3.8 and Chapter 9 for a more complete discussion of the performance approach.