ICC Addresses 15-Percent Glazing Area Code LanguageApril 22nd, 2016 by Editor
The International Code Council (ICC) 2016 Committee Action Hearings continued on this week, with decisions being made on a few notable glazing and fenestration industry-related proposals.
Wednesday, one very relevant proposal—RE145—was narrowly defeated, while three others were approved.
The industry supported RE145. This relates to the performance path, in which the builder has flexibility to make changes in the proposed home design and just has to show equivalent energy performance to a baseline home built to the prescriptive path.
The current code penalizes window area above 15 percent. According Tom Culp of Birch Point Consulting, this means “you can do it, but have to make up for it by making something else more energy efficient.” Window area at 15 percent or below remains neutral. RE145 would have made the window area neutral in all cases, with no penalty or credit for any window area, even above 15 percent. “That matches the prescriptive path which allows any window area, makes it simpler for the analysis,” says Culp.
Opponents of the change argued it would cause builders to increase window area. Proponents, however, cite a Pacific Northwest National Laboratory study for the Department of Energy that shows almost all homes are between 12 and 17 percent, and that “there is no evidence window area would be greatly increased, in part because of natural limitations such as cost and wall bracing requirements,” says Culp.
The initial vote was a 5-5, but the tie was broken by the chairperson, who voted to defeat the proposal.
RE146, meanwhile, was approved, 7-3. This sets the baseline window area at 15 percent, which keeps the same penalty for window areas above 15 percent, but now also gives a credit for lowering window area below 15 percent.
“This gives an incentive to reduce window area, which the window industry is obviously concerned about,” says Culp. “In reality, this will probably not change things too drastically in the real world, as homeowners want windows and no one wants to live in a cave, but this incentive could cause designers to take out a window here and there, and is a concern.”
Two other industry-related proposals—RE156 and RE134, were also approved.
Both set a “backstop” on the envelope, giving the flexibility to make changes in the traditional performance path or new energy rating index (ERI) path but also affirming that the envelope can only be traded off so much.
“This backstop says even if you exceed the energy performance in other areas like high efficiency equipment, use of solar panels, better lighting, etc., the envelope still has to be within 15 percent of the total area-weighted average of the 2018 prescriptive levels, and a modification also added that solar heat gain coefficient can be no worse than 0.40 in the southern zones,” says Culp. “For windows, doors, and skylights, this means that there is flexibility for compliance, but someone could not go so far as to remove the low-E and put in an inefficient double pane clear glass or single pane window, even if they make up for it elsewhere in the home.”
In other code updates, a change to the 2015 International Residential Code (IRC) R302.5 was approved related to garage opening and penetration protection in dwellings.
Openings and penetrations through the walls or ceilings separating the dwelling from the garage shall be in accordance with Sections R302.5.1 through R302.5.3. R302.5.1
This change declares that no openings may be built from a private garage directly into a room used for sleeping purposes. It also states that other openings between the garage and residence must be equipped with solid wood doors not less than 1 3/8 inches (35 mm) thick, solid or honeycomb-core steel doors not less than 1 3/8 inches (35 mm) thick, or 20-minute fire-rated doors equipped with a self-closing device or an automatic-closing device that is actuated by smoke detection or heat detection.
Another measure approved was a revision to R310.1 of the IRC, which requires emergency escape and rescue openings in basements, habitable attics and all sleeping rooms. The revision states that each of those areas shall have not less than one operable emergency escape and rescue opening. Where basements contain one or more sleeping rooms, an emergency escape and rescue opening shall be required in each sleeping room. Emergency escape and rescue openings shall open directly into a public way, or to a yard or court that opens to a public way.
Exceptions were provided for storm shelters and basements used to house mechanical equipment that do not exceed a total flor area of 200 square feet. Also excluded – dwelling or townhouses equipped with automatic sprinkler systems, as long as the sleeping rooms in basements has either one means of egress complying with Section R311 and one emergency escape and rescue opening, or two means of egress complying with Section R311.
Under the proposal, a minimum of one basement escape window or door plus a means of egress will still be required.
According to one proponent of the change, the cost savings associated with eliminating even one basement escape window and the associated ladder and window well can be significant. The incentive grows when it’s combined with the benefit of eliminating leakage and maintenance issues and tripping/fall hazards that may be associated with window wells. Finally, the change could offer an enormous benefit to builders, who will now be allowed to locate sleeping rooms in lot-constrained below-grade areas of walk-out basements, and to homebuyers, who will gain the option of finishing an unfinished basement without the constraint of having to locate sleeping rooms based on existing window locations or having to add windows to an existing basement.