## Draft Proposal CA-8

This concept has been developed by the DOE Building Energy Codes Program (BECP) as a possible code

change proposal to the Commercial provisions of the 2012 International Energy Conservation Code

(IECC). Interested parties are asked to submit any and all comments on DOE's initial concepts and draft

code change proposals. For instructions on submitting comments, visit:

www.energycodes.gov/development/ commercial/codes/iecc/concepts/



## Singular Performance Path – Appendix G of 90.1 (CA-8)

Objective: Create in the IECC a singular performance path to compliance, and require compliance be

based on a set reduction in energy cost for the proposed design over the standard design building.

Suggested Code Change Proposal

Revise Section C401.2 as follows:

C401.2 Application. Commercial buildings shall comp ly with one of the following:

1. The requirements of ANSI/ASHRAE/IESNA 90.1.

2. The requirements of Sections C402, C403, C4 04 and C405. In addition, commercial buildings

shall comply with either Section C406.2, C406.3 or C406.4.

3. The requirements of Section C402.4, C403.2, C404, C405.2, C405.3, C405.4, C405.6 C405.7

and C407. The building energy cost shall be e qual to or less than 85 percent of the standard

reference design building.

Add a new definition to Section C202 as follows:

REGULATED ENERGY USE. Energy used for HVAC, lighting, service water heating, motors,

transformers and other building systems, equipm ent, components, and processes with requirements

prescribed in this code.

Revise Section C407.1 as follows:

C407.1 Scope. This section establishes criteria for compliance using total expected building performance

of a proposed building design in terms of regulated energy use . The following systems systems and loads

shall be included in determining the total building pe rformance: heating systems, cooling systems, service

water heating, fan systems, lighting po wer, receptacle loads and process loads.Delete Section 407.3 and replace with the following:

C407.3 Performance-based compliance. Total building performance shall be calculated and

documented by a registered design professional in accordance with Appendix G of ASHRAE Standard

90.1 and shall show a minimum a performan ce percentage improvement of 26% of regulated energy use

when calculated in accordance with Section G. 1.2 of Appendix G. Energy that is not regulated energy use

shall be subtracted from both the proposed design and the baseline building after building performance

calculations are completed, but prior to calculating the percentage improvement.

Delete Sections C407.4, C407.5, and C407.6

Note: The target of 26% improvement in proposed section C407.3 above will change based on the final

development of 90.1

‐ 2013 Appendix G.

Reason: Since the first energy codes and standards were published almost 40 years ago, there has

always been a path to compliance that recognizes the ability for a building design to meet the intent of

the energy code or standard without necessarily meeting each and every minimum prescriptive

requirement. This path in the energy codes continues the concept embodied in the long

‐ standing

building code provision entitled “alternative methods and materials.” In short, the intent is to allow a

designer to show that their building as designed will perform at or better than if it were just designed to

meet the minimum code provisions.

While energy codes and standards provide criteria for HVAC, service water heating systems, and lighting

systems on an independent basis with each provision having to be satisfied, it is understandable that

one may wish to modify the design of prescriptive items and make up for increased energy use by

increasing efficiency elsewhere in the building. For instance, one might want to provide fenestration

that does not meet the prescriptive minimum code while at the same time implementing a reduction in

connected lighting power below that allowed in the code. The intent is to allow the degree to which

one building component or system does not meet minimum to be “traded off” against the degree to

which one or more others exceed the minimum. In effect this provision allows consideration of the

building as a whole, recognizing that energy use and associated operating costs of a building occur “at

the meter” and are the result of many interactions between the structure and the systems that provide

the myriad of services in the building.

Although the concept of “equal or better” performance of the actual building design to an assumption it

just met code sounds simple, it is not. For most commercial buildings, such calculations require

computer simulation by well

‐ versed professionals along with a number of directions to ensure accurate

results and minimization of gaming. Initially energy codes and standards had a singular set of criteria

that were to be followed when conducting such building performance analysis. Over time as ASHRAE

Standard 90 and the MEC (now the IECC) were maintained by different entities, the criteria associated

with this compliance path digressed, in part because of the amount of time and effort stakeholders and

others expended to update, maintain, and enhance the building performance approach. ASHRAE 90.1

has had and continues to have a long

‐ standing focus on this path to compliance that is ongoing and

constant, and is a referenced compliance path to the IECC anyway pursuant to C401.2 (1). This raisesthe question

— why have two separate processes focused on the same complex problem and instead why

not simply rely on one?

It is for the following reasons that this change is proposed:

 Annual energy analysis and simulation is complicated and the governing rules more likely to

improve if all interested and affected parties can focus their efforts on one approach.

 The types of commercial buildings that will use this compliance path will have registered design

professionals involved, so why not refer them to a singular approach?

 Code officials receiving compliance documentation associated with this path will have a uniform

and singular set of inputs/outputs to get comfortable with in addition to knowing all results they

receive are developed with the same identical “black box.”

 Those with expertise in building energy modeling are heavily involved in development and

updating of ASHRAE Standard 90.1, putting in easily a man

‐ year of labor each year to keep the

provisions in the standard current.

Cost Impact: There is a possible reduction in construction cost and the costs associated with plan

review and approval associated with this proposed change. Designers will have a single robust and

technically supported approach to use for building performance, which should streamline their efforts.

Similarly, code officials and plan reviewers will have a singular and uniform type of documentation to

review.