9.3 Compliance Approaches

Apart from meeting all applicable mandatory requirements as outlined in Section 9.4, an addition or alteration must also demonstrate energy compliance using a prescriptive or performance method.

There are number of different compliance alternatives or compliance paths to demonstrate that an addition or alteration meets the Standards. Compliance alternatives depend on whether the scope of permitted work is:

1. Addition Only where no changes are being made to the existing building except removal of roofs, exterior walls and floors required as a result of the addition; and removal of any fenestration in those same removed roofs and exterior walls to make way for the addition; or

2. Alterations Only where there is no addition (i.e., no increase in conditioned floor area and volume); or

3. Addition and Alterations where there are both additions and alterations to the existing building.

For each of these permit scenarios, Table 9-1 summarizes the available compliance approaches for low-rise residential additions and alterations.

Table 9-1: Compliance Alternatives for Residential Additions and Alterations

Project Scope	Prescriptive Approach	Performance Approach^{1, 2}
1. Addition Only:	Additions ≤400 ft²; or	Addition Alone
	Additions >400 ft² and ≤700 ft²
	Additions >700 ft²; or
2. Alteration Only:	Meet All Applicable Requirements for Prescriptive Alterations	Existing + Alterations Without Third Party Verification of Existing Conditions; or
		Existing + Alterations With Third Party Verification of Existing Conditions; or
		Existing + Alterations as All New Construction
3. Addition and Alteration Combined:	Meet All Applicable Requirements for Prescriptive Alterations and a Prescriptive Addition Approach (see Additions Only above)	Existing + Addition + Alterations Without Third Party Verification of Existing Conditions; or
		Existing + Addition + Alterations With Third Party Verification of Existing Conditions; or
		Existing + Addition + Alterations as All New Construction
1) In the performance method, the building must be modeled with Energy Commission-approved compliance software as explained in Chapter 8 of this 'Manual. 2) The Existing + Alterations performance approach with or without third party verification may be used only if there are at least two types of altered components in the existing building. This requirement does not apply to the Existing + Addition + Alterations compliance method.

9.3.1 ADDITIONS ONLY

The prescriptive standard requirements for new addition construction are listed in §150.2(a); however, prescriptive additions have some alternative requirements as summarized:

1. Additions of < 300 ft² or less do not require a cool roof to be installed;

2. Additions ≤ 400 ft²: Total glazing area up to 75 ft² or 30% of the conditioned floor area, whichever is greater; and up to 60 ft² of West-facing glazing area; wall insulation of R-13 is acceptable;

3. Additions > 400 ft²and ≤ 700 ft²: Total glazing area up to 120 ft² or 25% of the conditioned floor area, whichever is greater; up to 60 ft² of West-facing glazing area; and need not exceed R-13 insulation in exterior walls;

4. Additions > 700 ft²: Total glazing area up to 175 ft² or 20% of the conditioned floor area, whichever is greater; and up to 70 ft² of West-facing Glazing area.

Note that every applicable prescriptive requirement for additions must be met when using the prescriptive approach. Otherwise, the building as a whole must comply using a performance approach.

For prescriptive additions, a Certificate of Compliance (CF1R-ADD) form must be completed and submitted for permit. If any mandatory or prescriptive measures require HERS verification and/or testing, the Certificate of Compliance for the project must be registered online with a HERS provider before submittal to the enforcement agency. Refer to Section 2.5, HERS Field Verification and Diagnostic Testing and Section 2.2.2, Permit Application.

Additions may comply using the performance approach by meeting the requirements in §150.2(a)2 of the Standards and explained further in Section 9.5.2. The performance options are:

• Addition Alone: Only the addition is modeled for compliance, and not the existing building;

Existing + Addition as New Construction. Demonstrating compliance as a whole new building, combining existing plus the addition as all new construction, this approach is usually difficult to achieve, but still an option. Typically this approach is when the addition cannot comply on its own; it would require the existing building to help the addition to comply. Depending on the age of the existing building, the older the building the more revisions or alterations will be required to bring-in the existing and addition into compliance as a whole.

9.3.2 ALTERATIONS ONLY

Alterations may comply prescriptively by meeting all applicable requirements in §150.2(b) of the Standards as explained further in Section 9.5.1 of this manual and summarized in Tables 9-5A and 9-5B. Several prescriptive alteration requirements are specific to the building site climate zone. There are also a number of exceptions to the prescriptive requirements based on either climate zone or other conditions listed in the Standards.

Note: Every applicable prescriptive alteration requirement must be met to use the prescriptive approach; otherwise, the building must comply using a performance approach.

Under the prescriptive alteration approach, the appropriate Certificate of Compliance (e.g., CF1R-ALT or CF1R-ALT-HVAC) form must be completed and submitted for permit. If any mandatory or prescriptive measures require HERS verification or testing (see Section 2.5, HERS Field Verification and Diagnostic Testing of this manual), the Certificate of Compliance for the project must be registered online with a HERS provider (see Section 2.3, Energy Standards Compliance Documentation of this manual) before submittal to the enforcement agency.

Alterations may comply using the performance approach by meeting the requirements in
§150.2(b)2 of the Standards explained in Section 9.6.2, and summarized in Table 9-1. The main options are:

1. Existing + Alterations: When two or more types of components or systems are being altered in the existing building, then the Existing + Alterations performance approach may be used.

2. Compliance Without Third Party Verification allows for compliance of the alterations without the need for third party inspection to verify existing conditions being altered;

3. Compliance With Third Party Verification allows for compliance of the alterations only with third party inspection to verify existing conditions being altered;

4. Existing + Alterations as new construction: Demonstrating alterations compliance as a whole new building is usually difficult to achieve, but still an option. Typically this approach is used is when prescriptive alterations cannot meet the prescriptive requirements in Table 150.1-A.

Note: Every applicable prescriptive alteration requirement must be met to use the prescriptive approach; otherwise, the building must comply using a performance approach.

9.3.3 ADDITIONS and ALTERATIONS COMBINED

When a low-rise residential project includes both an addition and any alterations, the prescriptive requirements for each separate condition must be met for the prescriptive approach to be used. The addition may comply with any of the prescriptive addition options explained above and documented by the appropriate compliance forms (e.g, CF1R-ADD). However, the alterations must also meet all prescriptive requirements, and be documented with the specific compliance forms for alterations (e.g., CF1R-ALT, CF1R-ALT-HVAC).

The performance path that includes both additions and alterations is the “Existing + Addition + Alterations” approach. As explained above (under Alterations Only – Performance), there are two ways to analyze the building using this method: with third party verification of all existing conditions to be altered; and without third party verification. See Section 9.5.2.