Do you have comments or questions on this draft? Discuss them below with your fellow LEED professionals. Substantive comments posted here during USGBC's second public comment period  will be submitted to USGBC and considered "official" public comments.

More information on LEED 2012 certification and the second public comment

Indoor Environmental Quality (IEQ)

Major Changes

In a small but meaningful change for Schools projects, projects unable to meet the Minimum Acoustical Performance prerequisite due to limited scope of work can submit a narrative explaining their design decisions.

The Outdoor Air Delivery Monitoring, Increased Ventilation, and Indoor Chemical and Pollutant Source Control credits have all been eliminated.

There is a new Enhanced Indoor Air Quality Strategies credit (1–2 points), which is largely a repackaging of key requirements from those eliminated credits. Option 1 in this new credit (1 point) includes the key track-off, exhaust, and filtering requirements from LEED 2009’s IEQc5, and includes the key natural ventilation requirements that are part of IEQc2: Increased Ventilation in LEED 2009. Option 2 for this credit requires meeting Option 1, plus requirements that are similar to LEED 2009 requirements for increased ventilation over ASHRAE 62.1 and for outdoor air delivery monitoring. Those requirements are a bit more sophisticated, however, incorporating use of modeling to show that air contaminants will be below key exposure levels.

The second draft of LEED 2012 brings us a second major overhaul of Low-Emitting Interiors (1–3 points), although the overall systems approach introduced in the first draft remains. In that system, the building interior is organized into five systems: flooring, ceilings, walls, thermal and acoustic insulation, and furniture (which must be included if it is in the scope of the project). In this draft, rather than accumulating points by complying with the requirements of one or more systems, projects would try to improve their “total % compliant” score. This score would be an average of the “% compliant” score for each of the key systems. Projects don’t have to be perfect in any of the areas: 50%–70% compliance gets 1 point, 70%–90% gets 2 points, and 90% or more gets three points, and 90% or greater compliance in a single area is considered 100% compliance for the purpose of the average. Projects not making an effort in any major category will be penalized: less than 50% compliance in a single area is considere 0% for the average. Percent compliance is based on surface area for walls, floors, and ceilings, and on cost for furniture. Products will need to show compliance with the 35 VOC emission limits within the California Department of Public Health (CDPH) Standard Method V1.1-2010, often referred to as California Section 01350, and they will also need to report their total TVOC levels.

Indoor Air Quality Assessment (1–2 points) is the new name for Construction IAQ Management Plan—Before Occupancy. The big change here is that the Option 1 flush-out path preferred by most LEED projects would be downgraded to one point, versus two points for Option 2: Air Testing. (Testing better ensures lower levels of contaminants, but introduces more uncertainty for project teams.) Changes to the testing requirements include specification that typical ventilation rates be used, and there are also changes to the chemicals. Testing of carbon monoxide and 4-PCH would no longer be required, but all target chemicals under CDPH Standard Method V1.1-2010 would be. In other changes, furniture would have to be installed, and samples from the entire building and “representative situations” would be explicitly required.

The new Interior Lighting credit (1–2 points) covers the scope of the LEED 2009 “Controllability of Lighting” credit, which falls under Option 1 (1 point), and Lighting Quality can optionally be pursued for a separate point under Option 2. Changes to the lighting control requirements put specific emphasis on providing three lighting levels (or “scenes”) for individual and multi-occupant spaces: on, off, and mid-level. For lighting quality, projects would have a choice of meeting four (changed from five under the first draft) out of eight (changed from 12) quality measures. These measures include color rendering index (CRI) requirements and use of reflective surfaces.

An Acoustic Performance credit (1 point) was previously only available to Schools projects remains available to NC projects in this draft. However, it has been overhauled: in place of a fairly vague, performance-based approach, projects would now have to achieve numerous, specific acoustical ratings defined in the credit language.

Minor Changes

Minimum IAQ Performance (required) still references minimum ASHRAE-62.1 requirements. Outdoor air delivery monitoring requirements are included for CS projects.

Environmental Tobacco Smoke Control sees a fine-tuning of requirements rather than any major change (such as absolute prevention of smoking). Non-smoking requirements extend to outdoor spaces used for business purposes, like patio seating. Language for residential projects that specifically prohibited smoking on balconies is eliminated.

Requirements for a Construction IAQ Management Plan during construction are remain largely unchanged (with some adjustments to wording), but have become a prerequisite instead of a credit.

The Thermal Comfort credit (1 point) is updated to newer standards such as ASHRAE 55-2010, but is otherwise mostly unchanged.

The Daylight credit (1–3 points), overhauled in the first draft of LEED 2012, doesn’t see many additional changes in this second draft. Two simulation options remain, Option 1: Simulation – Daylight Autonomy (2–3 points), and Option 2: Simulation – Illuminance Calculations (1–2 points). A third option, Measurement, remains for one point. With a new 90% threshold for Options 1–2, this credit has more value compared with LEED 2009.

The LEED 2009 credit on views became Quality Views (1 point) in the first LEED 2012 draft, and thus it remains. USGBC has tweaked some of the calculation details, noting, for example, that if fixed window treatments are used for the credit, occupants should be able to discern movement and faces through the treatment.

What do you think of the proposed changes for LEED 2012? Post your thoughts below.