International Code Requirements for Windows & Doors

Enforcement of the International Codes by a number of states and local jurisdictions has begun. At the beginning of 2008, 18 states (Alabama, Alaska, Georgia, Hawaii, Idaho, Iowa, Kentucky, Louisiana, Maryland, Minnesota, Montana, New Hampshire, New Jersey, Ohio, Pennsylvania, Rhode Island, Utah and Washington) are enforcing the 2006 International Building Code, with another two (New York and North Dakota) expected to begin enforcing it soon. Enforcement of the 2006 International Residential Code has also been widespread, with 15 states (Alabama, Georgia, Idaho, Iowa, Louisiana, Maryland, Minnesota, Montana, New Hampshire, New Jersey, Ohio, Pennsylvania, Rhode Island, Utah and Washington) currently enforcing it statewide and another three (Kentucky, New York and North Dakota) expected to begin enforcing it soon.

The 2006 International Energy Conservation Code is also beginning to be adopted and enforced, although not on the same scale as the 2006 IBC and IRC. At present, nine states (Idaho, Iowa, Kansas, Maryland, New Jersey, Ohio, Pennsylvania, Rhode Island and Utah) are enforcing the 2006 IECC on a statewide basis. Since the 2000 or 2003 International Codes were already in use in 49 states and several U.S. territories when the 2006 International Codes became available last year, jurisdictions simply needed to update the edition in use instead of transitioning to a new code, which facilitated the adoption and enforcement of the 2006 I-Codes. Numerous federal agencies have also adopted the International Codes, including the National Park Service and the U.S. Department of Defense.

The ICC has two complete code change cycles between each edition of the International Codes, which are published at three year intervals. In 2007, the first cycle for revision of the 2006 International Codes was completed and a resultant 2007 Supplement to the 2006 International Codes was published.

There were several significant changes in the 2006 codes that manufacturers, distributors and dealers should note. These changes included a complete rewrite of the energy conservation provisions in both the IECC and the IRC, and the establishment of minimum window sill heights. Further changes made in the 2007 Supplement include additional revisions to the energy code requirements, limits on the use of wood structural panels as an alternate to impact resistant openings in wind borne debris areas and the addition of requirements for special inspections of exterior wall cladding systems.

The following is designed as an introduction to the major requirements set forth for windows, doors and other fenestration products in the 2006 IBC, IRC and IECC, with indications of some of the changes that occur in the 2007 Supplement. Please be aware that this is not a full discussion of all the requirements of the 2006 International Codes or the 2007 Supplement to the 2006 International Codes. It should also be noted that since most jurisdictions do not adopt or enforce the Supplements to the International Codes, it is not likely that the Supplement provisions will begin to be enforced until we see enforcement of the 2009 editions of the codes. There is also a possibility that some of the provisions approved for the 2007 Supplement may be modified or deleted during the next ICC code change cycle. In that case, the provisions described below for the 2007 Supplement may never actually be enforced. More detailed information can be obtained from the codes themselves. For more information about the International Codes, and to order the 2006 IBC, IRC or IECC, or the 2007 Supplement to the 2006 International Codes, contact the International Code Council.

WINDOWS AND DOORS
Exterior windows and doors are covered in Section 1714.5 of the 2006 IBC and Section R613 of the 2006 IRC. These sections require windows and sliding doors to be tested and labeled in accordance with AAMA/WDMA/CSA 101/I.S.2/A440-05. The reference to AAMA/WDMA/CSA 101/I.S.2/A440-05 represents an update of the 2006 IBC, IECC and IRC from the previous reference to ANSI/AAMA/WDMA 101/I.S.2/NAFS-02 and AAMA/NWWDA 101/I.S.2-97, and brings together the requirements of the U.S. and Canadian window standards into one document for the first time. The standard was developed jointly by the American Architectural Manufacturers Association, the Window & Door Manufacturers Association and the Canadian Standards Association. (The complete document and more information are available from all three organizations.)

In the 2003 IBC/IRC, the AAMA/WDMA standard applied to windows and glass doors. In the 2006 IBC/IRC, the latest edition of the standard will apply to windows and "sliding doors." The change was made from glass doors to sliding doors through mutual agreement between AAMA, WDMA and the Association of Millwork Distributors. The phrase "glass doors" has led to interpretation difficulties in the past. It was thought that the phrase "sliding doors" would more clearly define the type of doors that must be tested and labeled in accordance with AAMA/WDMA/CSA 101/I.S.2/A440-05

Other types of fenestration assemblies, including curtain wall, storefront and swinging doors, are also addressed in Section 1714 of the 2006 IBC and Section R613 of the 2006 IRC. Most of these assemblies are to be tested to 1.5 times design load in accordance with ASTM E330-02, and the glass is to be designed in accordance with ASTM E1300- 02. Manufacturers of exterior swinging doors will be able to take advantage of either option. These types of doors can be tested and labeled in accordance with AAMA/WDMA/CSA 101/I.S.2/A440-05 or tested to 1.5 times design load in accordance with ASTM E330-02. The 2007 Supplement to the 2006 IBC will also permit garage doors to be tested to ANSI/DASMA 108, in lieu of ASTM E330.

AAMA/WDMA/CSA 101/I.S.2/A440-05 sets requirements for products by performance class. The five performance classes addressed are Performance Class R, LC, C, HC and AW. The performance class and design pressure rating required for a particular application is determined by the designer of record for the project based on its intended end-use conditions, and the design wind pressures of the IBC or IRC. Structural test pressure requirements, resistance to air leakage, water infiltration, forced entry and several other performance characteristics are specified by AAMA/ WDMA/CSA 101/I.S.2/A440, based on the operator type, the chosen performance grade and the required DP rating for the product.

Labeling of the window or sliding door must be done through an independent third-party product certification agency. The label provides verification that the product certification agency has reviewed product test reports, found the product to be in compliance with the specified standard and maintains periodic inspections of its production.

The 2007 Supplement will require that exterior wall cladding systems, including curtain wall, storefront and punched openings, in high wind areas are to be subject to special inspections. The high wind areas are determined by exposure category of the building. If the building is in Exposure Category B (low- to mid-rise buildings) then special inspection will be required if the design wind speed is 120 mph or greater. If the building is in Exposure Category C (open prairies) or D (near large bodies of water) then special inspections will be required if the design wind speed is 110 mph or greater.

Special inspections, by definition in the IBC, are to be performed by persons who are specifically qualified to inspect the installation in question. They are only required for that part of the system design that requires a registered design professional. So for a curtain wall system the special inspection would be of the structural components—the framing members, the anchorage, joinery, etc. DESIGN Loads Provisions for design loads are set forth in Section R301 of the 2006 IRC and Chapter 16 of the 2006 IBC. The design loads of concern for vertical glazing are design wind load, impact resistance and dead load. Skylights and sloped glazing are also subject to snow load and dead load.

WIND & DEAD LOADS
Tables R301.2(2) and R301.2(3) of the 2006 IRC give the design wind loads for glazed openings, based on the design wind speed of the specific location where construction is to take place, the mean height of the building and its exposure. These tables are based on the design wind loads set forth in the 2006 IBC, which in turn refer to ASCE 7-05. ASCE 7-05 is a standard from the American Society of Civil Engineers for the determination of design loads for buildings and other structures. The provisions for dead load in Section 1606 of the 2006 IBC are also based on ASCE 7-05.

The most significant changes to the wind- and dead-load requirements for fenestration in the 2006 IBC and 2006 IRC that are relevant to exterior fenestration are those related to the protection of openings from impact.

IMPACT RESISTANCE
Section 1609.1.3 of the 2006 IBC and Section R301.2.1.2 of the 2006 IRC outline the locations where impact-resistant products are required. In the 2003 IBC and 2003 IRC, protection of the opening from impact was only required if the building itself was not designed to resist the internal wind pressures that can occur if the opening is breached during a hurricane or other high-wind event. In the 2006 IBC and 2006 IRC, the option for internal wind pressure design is absent.

All exterior openings in wind-borne debris areas are required to be impact resistant in the 2006 IBC and 2006 IRC. The geographical locations where impact protection of openings is required are similar to ASCE 7-05.

Products that need to meet impact-resistance requirements must be tested to one of a few different sets of standards. One option that exists in both the 2006 IBC and 2006 IRC is testing in accordance with ASTM E1886-02 and ASTM E1996-02, which must be used together. The 2006 IRC also recognizes an AAMA certification label denoting compliance to AAMA 506 Voluntary Specifications for the Hurricane Impact and Cycle Testing of Fenestration Products as evidence that a product has been tested appropriately. The AAMA 506 labeling program provides a method for window manufacturers to demonstrate that their product has been successfully tested in accordance with ASTM E 1886-02 and ASTM E 1996-02 by placing a label right on their product, rather than having to provide test reports for each project. Both the 2006 IBC and IRC will also permit the use of "other approved tests." This may include Miami-Dade County test protocols, if approved by the authority having jurisdiction.

For residential applications, use of protective wood panels as an alternative to impact-resistant glazing or shutters is permitted. The 2006 IBC and IRC will limit the use of protective wood panels to protect the openings in buildings with a mean roof height of 33 feet or less in locations with a design wind speed of 130 miles per hour or less. The 2007 Supplement will further limit the use of wood structural panels to one and two family dwellings and residential care facilities, but will increase the mean roof height of homes they may be used on from 33 feet to 45 feet, and will increase the design wind speed from 130 mph to 140 mph. The reason for these limits is that installing plywood over openings on a ladder when a hurricane is approaching is a hazardous activity in its own right that should not be encouraged or needed to protect one's home. Also, one and two family dwellings are more likely to be occupied by someone who has a vested interest in preserving the home and its contents, who is more likely to take the time to learn how to install the shutters and to actually do so than in other types of residential buildings such as apartment buildings or dormitories.

SAFETY GLAZING
Section 2406.3 of the 2006 IBC and Section R308.4 of the 2006 IRC establish the locations where safety glazing is required. They include the following:

• glazing in and near swinging and sliding doors;
• large lites of glass near walkways;
• glazing around tubs, showers, pools and similar fixtures;
• glazing near stairways, ramps and the landings for both

In these applications, the glazing must be labeled per the Consumer Products Safety Commission CPSC 16 CFR 1201 requirements. There are some exceptions for applications that are considered less hazardous, such as very small openings in doors, decorative glass, glazing provided with a protective bar, etc. The previous exception for wired glass in fire-rated assemblies that complied with ANSI Z97.1 in other than educational-use groups has been removed. In the 2006 IBC, wired glass will only be permitted if it meets CPSC 16 CFR 1201, just like any other type of glass. The 2007 Supplement will permit the use of glass that meets the two most stringent categories of ANSI Z97.1 in hazardous locations that are defined within the 2006 IBC and IRC, but which do not fall within the scope of the federal law established by CPSC 16 CFR 1201. These locations include tub and shower enclosures, door sidelites, large lites of glass, and glazing near stairs, ramps and pools. The criteria for these two categories of ANSI Z97.1 are similar to CPSC 16 CFR 1201 for these applications, but ANSI Z97.1 was updated in 2004, while CPSC 16 CFR 1201 was last updated in 1977. Therefore ANSI Z97.1 is considered to be more up to date and consistent with products currently available than CPSC 16 CFR 1201.

Although the defined hazardous locations did not change between the 2003 International Codes and the 2006 IBC and 2006 IRC, a couple of the exceptions did. Perhaps of greatest significance to the residential window manufacturer will be the addition of another exception to the requirement for safety glazing near stairs and ramps. This exception says that glazing near a stairway or ramp is not required to be safety glazing if a solid wall or panel extends from the walking surface adjacent to the stairway or ramp to a height of 34 to 36 inches, and the top of that wall or panel is capable of withstanding the same horizontal load as the protective bar. Although not specified in the language, it appears that the intent is to apply the same criteria to the top of the wall or panel as is applied to protective bars used over large lites of glazing in hazardous locations.

ENERGY
The 2006 IECC has been completely rewritten, with massive changes between it and the 2003 IECC. Among the most significant changes arethe reduction in the number of compliance path options available for residential construction, the reduction of climate zones from 19 to eight and the elimination of percentage of glazing or window-wall ratio in determining the U-factor and SHGC for fenestration. These massive changes are also reflected in the energy efficiency requirements for one- and two-family dwellings and town homes three stories or less in height in Chapter 11 of the 2006 IRC.

Several different methods of energy conservation compliance were provided in the 2003 IECC and Chapter 11 of the 2003 IRC. These were known as compliance paths. Some of the compliance paths were very performance oriented, and permitted a more energy-efficient component of a building to be used as a tradeoff for another, less energy-efficient component in the same building. Other methods were prescriptive, and specified the exact requirements for each component in the building.

The 2006 IECC has only three compliance paths. The simplest gives one set of energy efficiency requirements for each component of the building envelope, regardless of the percentage of glazing in the exterior wall. Fig. 1 on the previous page shows the U-factor and SHGC values given for vertical fenestration in residential construction under these provisions. The U-factor is to be determined in accordance with NFRC 100-01 or by use of a default table in the 2006 IECC and 2006 IRC. Similarly, the SHGC of the fenestration is to be determined in accordance with NFRC 200-01 or by use of a default table.

The prescriptive requirements for skylights in residential construction are also greatly simplified in the 2006 IECC. The maximum U-factors for skylights correspond to the maximum U-factors for vertical fenestration as shown in Fig. 1.

The other two compliance paths in the 2006 IECC permit some tradeoffs in levels of energy efficiency from one building component to another. One of these—designated the UA alternate method—only permits tradeoffs between different elements of the building envelope. The other method, performance-based design of the whole building, permits tradeoffs between all the energy efficiency components of the residence, including the HVAC system as well as the building envelope.

The amount of tradeoff that is permitted for fenestration is capped, however. In the northern climate zones (climate zones 6 to 8, which correspond roughly with Wisconsin to Alaska), the U-factor cap is 0.40. In mid-level climates zones 4 and 5 (northern Tennessee to southern Wisconsin), the cap is 0.48. In southern climate zones 1 to 3 (Tennessee on south to the tip of Florida), there is no U-factor cap, but the SHGC is capped at 0.50. When one of the other alternative compliance paths is used, the U-factor cap on skylights in climate zones 4 to 8 is 0.75. The same SHGC cap of 0.50 that applies to vertical fenestration in climate zones 1 to 3 also applies to skylights.

The prescriptive method and the UA method from the 2006 IECC also appear in Chapter N11 of the 2006 IRC. The prescriptive maximum U-factors and SHGC are the same as those indicated in the map at left, but the caps available if the alternate UA method is used are higher. In the 2006 IRC, if the UA method is used, the maximum U-factor in climate zones 6 to 8 is 0.55. There is no cap in climate zones 1 to 5. Therefore, in the 2006 IRC, other components of the building envelope, such as increased wall insulation, could be used to trade off for less energy-efficient windows with no limit on how poor the energy performance of those windows might be. In the 2007 Supplement to the 2006 IRC this cap has been removed in its entirety, but the cap remains in the 2007 Supplement to the 2006 IECC.

The homebuilder still has the option of using the whole building performance-based design method given in the 2006 IECC instead of the methods given in the 2006 IRC. In that case, however, the fenestration is subject to the more stringent caps of the 2006 IECC, as discussed above.

It should be noted that the U-factor requirements discussed also apply to all exterior doors, whether glass or opaque. Glass doors, by definition in the IECC, are considered to be doors which are more than 50 percent glass in area. If the door is equal to or less than 50 percent glass in area, it is considered to be an opaque door. Although opaque doors are included in the definition of fenestration area in the 2006 IECC, 2006 IRC and 2007 Supplement, the 2006 IECC and 2006 IRC assigned a maximum U-factor of 0.35 to all opaque doors, separate from the U-factor requirements for glazing area.

One opaque door is exempt from this requirement in the 2006 IECC and 2006 IRC. In the 2006 IECC and 2006 IRC, glass doors are included in the overall U-factor requirements for fenestration.

The 2006 IECC and 2006 IRC require air-leakage resistance of window and door assemblies to be determined in accordance with AAMA/WDMA/CSA 101/I.S.2/A440 Ð 05 or NFRC 400-01, similar to the requirements in the 2003 IECC and IRC. The 2006 IECC also requires air-leakage resistance of curtain wall, storefront glazing and commercial doors to be determined in accordance with ASTM E 283-99.

MINIMUM WINDOW-SILL HEIGHTS
Another major change in the 2006 IBC and 2006 IRC is the introduction of 24-inch minimum sill heights for operable windows that are a certain distance above the grade outside the window. The intent of this requirement is to reduce the number of children injured by falling through windows every year.

The exact requirement is that the bottom of the opening created by an operable window must be at least 24-inches above the finished floor of the room in which the window is located, if the rough opening for the sill is more than 72 inches above the ground or other surface below the window. An exception is provided for windows that do not open more than 4 inches or that are equipped with window guards that comply with ASTM F2006- 00 or ASTM F2090-01a.

THRESHOLD HEIGHTS
Section R311.4.3 of the 2006 IRC restricts the threshold height of the required exit door in residences to 11Ú2 inches from the top of the threshold to the floor or landing on each side of the door. The rise from floor or landing to the top of the threshold at other exterior doors is limited to 7 3Ú4 inches, which is the riser height permitted for stairs.

Section 1008.1.6 of the 2006 IBC restricts the threshold height of required means of egress doors in commercial buildings to 1 1Ú2 or 3Ú4 inch, except for exterior doors in apartments and town houses that are not required means of egress doors, and are not required to be an accessible Type A or Type B unit. The threshold height on the latter group of doors will be limited to 7 3Ú4 inches, similar to the provisions of the 2006 IRC for residential exterior doors that are not the required exit door.

MULLIONS
The 2006 IRC requires testing or structural calculations to demonstrate the ability of window mullions to meet certain structural requirements. If structural calculations are used to determine adequacy, the deflection of the mullions is limited to L/175 of the length of the long edge of the glass being supported. If testing is the method used to determine structural adequacy of mullions, the testing is to be done in accordance with AAMA 450-06 Voluntary Performance Rating Method for Mulled Fenestration Assemblies. When the mullion is tested in accordance with AAMA 450-06, the deflection limit of L/175 does not need to be met

REPLACEMENT WINDOWS
As a general rule, when an addition is made to a building or a component within a building is replaced, the International Codes require the new component or addition to comply with the requirements of the code for new construction. This is true for replacement windows. Both the 2006 IECC and 2006 IRC require replacement windows to comply with the requirements for fenestration in new construction. This requirement applies whether the entire window unit, including frame, sash and glazing, is being replaced, or just the sash and glazing.

SUNROOM ADDITIONS
The 2006 IECC permits glazing in thermally isolated sunrooms to have a U-factor of 0.5 or less in climate zones 4 to 8. By definition, the glazing area of sunrooms is 40 percent or more of the gross area of the structure's exterior roof and wall. A thermally isolated sunroom must be separated from the remainder of the building by either existing exterior wall construction or construction that meets the energy efficiency requirements of the 2006 IRC for exterior walls. The sunroom must also be equipped with a separate heating or cooling system or thermostatically controlled as a separate zone, if conditioned

Previous editions of the IECC placed size restrictions on thermally isolated sunrooms and referred to them as additions. Both of these elements have not been carried over to the 2006 IECC or 2006 IRC. Under the 2006 IECC and 2006 IRC, sunrooms can be built as part of new construction, but they must still be thermally isolated from the remainder of the home, as discussed above, to use the U-factor of 0.50 rather than 0.35 in climate zones 5 to 8, or 0.40 in climate zone 4.

SITE-BUILT GLAZING
Chapter 24 of the 2003 IBC contained prescriptive provisions for the design of glass in site-glazed construction based on the 1998 edition of ASTM E1300-98. These prescriptive provisions could be used if the glass framing did not deflect more than L/175 of the length of the edge of glass, or 3/4 inch, whichever was less. All other site-glazed systems were required to be designed by a registered design professional. The 2003 IRC referred to the 2003 IBC for site-glazed construction. In the 2006 IBC, the prescriptive provisions for glass design have been removed, and the reference to ASTM E1300 for glass design updated to the 2004e01 edition. The 2004e01 edition of ASTM E 1300 addresses several new types of glass lay-ups and support combinations that were not addressed in the 1998 edition. Having it referenced in the 2006 IBC will greatly enhance the designer's options in terms of providing glazed openings that can meet all the requirements of the code, including energy efficiency and impact resistance.

The provision that requires glass to be designed by a registered design professional if the glass framing deflects more than L/175 remains in the 2006 IBC. An exemption to this requirement is given in Section 1714.5 of the 2006 IBC for exterior windows and doors that are tested and labeled in accordance with AAMA/ WDMA/CSA 101/I.S.2/A440 Ð 05.

SKYLIGHTS AND SLOPED GLAZING
Similar to vertical glazing, the 2006 IBC and 2006 IRC have different requirements for unit skylights than for other types of glazed assemblies in roofs such as skylights and sloped glazing. Unit skylights that contain only one panel of glazing material are required to be tested and labeled for performance grade in accordance with AAMA/WDMA/CSA 101/I.S.2/A440-05 in both the 2006 IBC and IRC. Section 2405.5 of the 2006 IBC establishes the required performance-grade rating based on the provisions of that code for wind, snow and dead loads.

As for vertical glass, glass in sloped glazing is to be designed in accordance with ASTM E 1300-04e01. The prescriptive tables for design of glass in sloped glazing have been removed.

The requirements for screening under skylights and sloped glazing, as set forth in Section 2405 of the 2006 IBC and Section R308 of the 2006 IRC, are consistent with previous editions of the International Codes. This includes requiring the screening to be securely fastened to the framing and to be able to support twice the dead weight of the glass. Requirements for curbs on skylights and sloped glazing, when applicable, are also consistent with those in the previous editions of the International Codes, and are set forth in Section 2405 of the 2006 IBC and Section R308 of the 2006 IRC.

Emergency Escape and Rescue Openings Another window-and-door related requirement addressed in the I-Codes is minimum sizes for emergency escape and rescue openings. Typical requirements for sizes, locations, etc., are set forth in Section 1026 of the 2006 IBC and Section R310 of the 2006 IRC. It is important to note that the required opening size of 24 inches high, 20 inches wide and 5.0 or 5.7 square feet in area must be met by "normal" operation of the window. Operable skylights and roof windows are also permitted as emergency escape and rescue openings if they meet these requirements and the bottom of their opening is within 44 inches of the floor below.

Under the 2006 IRC, the emergency escape and rescue opening must be openable without the use of keys, tools or special knowledge. The 2003 IRC did not specify that special knowledge could not be used to open the window or door.

The 2006 IRC also requires emergency escape and rescue openings in all basements, except those that are used only to house mechanical equipment and are less than 200 square feet in area. The 2003 IRC only required emergency escape and rescue openings in basements with habitable rooms. Both editions continue to require emergency escape and rescue openings in sleeping rooms below the fourth floor of a building.

FIRE-RATED GLAZING
Fire-resistance-rated glazing is not required in the 2006 IRC, unless glazing is provided in the door between a residence and an attached garage. In that application, the door is required to be either a solid wood door not less than 13Ú8 inches (35 mm) in thickness, solid or honeycomb core steel door not less than 13Ú8 inches thick or a 20-minute fire-rated door. If glazing were to be used in this application, the implication of the IRC text is that it would have to be consistent with the requirements of the IBC for glazing in a 20-minute fire-rated door.

Chapter 7 of the 2006 IBC gives the requirements for fire-resistant-rated glazing in commercial buildings. These include testing and labeling requirements and size limitations. The 2006 IBC permits glass that has successfully passed the requirements of Chapter 7 for fire-resistance walls to be rated and labeled as a fire-resistant-rated wall. Glazing that has successfully met this criteria can be installed as a fire-resistant-rated wall with no limit on the size or area of glass.

The 2006 IBC also gives new requirements for the labeling of fire-protection-rated glazing. The new labeling system will use various letters to indicate the specific service conditions the glass has been tested for. The letter "W" is used to designate glazing that has been tested for installation in a fire barrier wall. The letter "D" indicates that the glazing has been tested for installation in a fire door. The "D" is then to be followed either by an "H" or "NH" to indicate that the glazing has passed the hose stream test (H) or has not (NH), and either "T" or "NT" to indicate the glass has been tested for end temperature (T) or not (NT).