Seattle Energy Code

Nonresidential & Multifamily Residential Energy Tips

 *** Section and Table references below are correct for the 2009 Seattle Energy Code, but work is still in process to update the links. ***

Note that this information is of a general nature and is not a substitute for the language in the code. Code compliance for a particular project is determined based on materials submitted in a permit application.

These tips for key Energy Code requirements are intended to provide (1) a short summary, (2) the intent, (3) the easiest way to show compliance, and (4) things to watch out for.

• General application of the Nonresidential & Multifamily Residential Energy Code
• Best ways to show compliance
• Application to existing buildings
• Nonresidential & Multifamily Residential fenestration requirements
• Nonresidential & Multifamily Residential insulation requirements
• Energy efficiency tips

GENERAL APPLICATION OF THE NONRESIDENTIAL & MULTIFAMILY RESIDENTIAL ENERGY CODE:

• Other than Single-Family Residential. Effective with the 2009 Energy Code, residential spaces no longer all have the same requirements.  The Single-Family Residential Energy Code (Chapters 1-10) covers all spaces within the scope of Section R101.2 of the Seattle Residential Code. (This only includes single-family dwellings, duplexes, and certain attached townhouses.)  As of the 2009 Energy Code, multifamily residential spaces are subject to Chapters 11-15.  Multifamily residential is defined in Chapter 2 of the Energy Code as all Group R Occupancy not falling under the scope of Section 101.2 of the Seattle Residential Code including, but not limited to, dwelling units, hotel/motel guest rooms, dormitories, fraternity/sorority houses, hostels, prisons, and fire stations; AND all sleeping areas in Group I Occupancy including, but not limited to, assisted living facilities,nursing homes, patient rooms in hospitals, prisons, and fire stations; AND all sleeping areas in other occupancies including, but not limited to, fire stations. Nonresidential spaces (all spaces that are not residential spaces), are subject to Chapters 11-16 of the Seattle Energy Code.
• Space by space determination. Occupancies are determined on a space by space basis, not on a building basis. Thus, in a building with three upper floors of apartments, one street level floor of retail shops, and two floors of below-grade parking: the apartments would be subject to the requirements for Multifamily Residential and the retail and parking would be subject to the requirements for Nonresidential spaces.  In some cases, the requirements are the same, and in other cases, they differ.
• Application of Seattle amendments to residential spaces. Seattle amendments do not apply to residential spaces, except that procedural requirements and informative notes in boxed text or brackets, and amendments to administrative and enforcement provisions, apply to all projects.

BEST WAYS TO SHOW COMPLIANCE:
The Nonresidential & Multifamily Residential Energy Code contains three options for demonstrating Energy Code compliance. The options listed in order of preference are:

• Prescriptive Option. ALWAYS use this option if it works for your project. It requires the least calculations on your part, which means fewer for the plans examiner to review. Prescriptive requirements are based on standard construction techniques and there are many commonly available products to choose from. No matter how sophisticated your design process is, that does not mean that you need to choose a complicated compliance process.
• Component Performance Option. Consider this option if the glazing area in your project exceeds 40% of the gross wall area or if you want to install less insulation than the Prescriptive option requires. Be aware that you'll need to improve the energy-efficiency in some other area to make up for those areas that do not meet the Prescriptive requirements. Use either the Envelope UA form or, for nonresidential spaces only, the EnvStd program. EnvStd will allow tradeoff between heating and cooling requirements).(Note that the Washington State Energy Code Envelope UA form and the ASHRAE 90.1 version of EnvStd are NOT acceptable.
• Annual Energy Analysis Option (RS-29). Consider this option if neither the Prescriptive option nor the Component Performance option works. Because this option requires very detailed analysis with many assumptions (such as how to model shading by adjacent buildings, appropriate internal loads, HVAC zoning, etc.), it is strongly recommended that a meeting be held with the DPD Energy/Mechanical Plan Review staff to discuss assumptions for the modeling procedure prior to beginning the analysis. Use one of the computer programs listed in RS-29.

NONRESIDENTIAL & MULTIFAMILY RESIDENTIAL PRESCRIPTIVE COMPLIANCE OPTION:

• Climate zones. The Prescriptive option Building Envelope requirements for Seattle are in Table 13-1. (Seattle is in King County and so is included in Climate Zone 1. For other portions of Washington State, see the Climate Zone categories in Section 1303.)

APPLICATION TO EXISTING BUILDINGS:

• Applies to additions and alterations as well as new construction. Alterations and additions must also comply with the Energy Code requirements. See Section 1132.1 for the Building Envelope, Section 1132.2 for mechanical systems, and 1132.3 for lighting and motors.  For example, if wood windows are replaced, the U-factor must be 0.28 or less if the fenestration area is 30-40% of the gross wall area.
• Change of occupancy or use or space conditioning. Any unconditioned space that is altered to become semiheated, cooled, or fully heated, or any semi-heated space that is altered to become cooled or fully heated space shall be required to be brought into full compliance with the Code.  In addition, any nonresidential space which is converted to multifamily residential space shall be brought into full compliance with the Code.  Any multifamily residential space which is converted to nonresidential space shall be required to comply with the provisions for alterations.

NONRESIDENTIAL & MULTIFAMILY RESIDENTIAL FENESTRATION REQUIREMENTS:

• Fenestration. The definition of fenestration (Section 201) includes all assemblies that transmit light - not only typical windows and skylights, but also curtain walls, translucent plastic panels, clerestories, glass block walls, and sliding glass doors and other doors that are more than one-half glass.  Note that fenestration is further subdivided by frame material and operator type.
• Fenestration area. The definition of fenestration area (Section 201) includes the total area of the fenestration
  measured using the rough opening, and including all components of the fenestration assembly - the
  glass/plastic, sash, and frame.
• U-factors, Solar Heat Gain Coefficient (SHGC), and Visible Transmittance (VT) to be determined, certified, and labeled in accordance with NFRC procedures. The Energy Code specifies standard rating procedures, certification, and labeling (Section 1312) so that products may be compared on a consistent basis: NFRC 100 for U-factor and NFRC 200 for SHGC. (The National Fenestration Rating Council was specified as the developer of the national system of glazing energy ratings in the 1992 Energy Policy Act.) These rating procedures address the complexity of today's fenestration technologies - frames composed of several different materials, low-emissivity coatings, suspended films, argon and krypton gas fills, low-conductance spacers. For additional information about the rating procedures and about obtaining a copy of the NFRC Products Directory, see DPD Client Assistance Memo #403 and the NFRC website.
• Default must be used for products without NFRC certification and labels. Energy Code compliance is based on NFRC certification. Products which do not are not certified to the NFRC procedures, as indicated by a label on the product, are required to use the default values in Section 1006, Table 10-6. Manufacturer's data is NOT an acceptable alternate.
• Verify NFRC certification and labeling. Be cautious about manufacturers' claims which seem to offer performance which is significantly better than the Energy Code requirements. Verify that the U-factor, SHGC, and VT has been determined, certified, and labeled in accordance with the NFRC Product Certification Program (Section 1312.1). Make sure that this requirement is included in the job specifications. Make sure that the performance values are for the entire fenestration product, not only for the center of the glass, or for the panel without the frame. A computer simulation or a test report to an NFRC procedure does NOT indicate compliance with the NFRC certification and labeling program. If in doubt, ask the manufacturer for a copy of the Product Certification Authorization and contact NFRC to ensure that the manufacturer is participating in the NFRC Certification Program.

NONRESIDENTIAL & MULTIFAMILY RESIDENTIAL INSULATION REQUIREMENTS:

• Insulation ratings. Some insulation literature (particularly for rigid insulation) rates insulation R-values at several different temperatures. The R-value for insulation used for the building envelope is to be determined at 75°F (not 40°F or other temperatures).

NONRESIDENTIAL & MULTIFAMILY RESIDENTIAL ENERGY EFFICIENCY TIPS:
The Energy Code only establishes minimum requirements for energy efficiency. There is much more that can be done to achieve greater energy efficiency. In order, here are some suggestions to consider.

• Use efficient lamp sources.
• Reduce the space heating and space cooling load.
• Meet the remaining load efficiently.
• Use water heating carefully.
• Pick energy efficient appliances.
• Additional information. For additional information, see Sources of Information on Energy Efficiency.