ment to participate in many of the utility incentive programs. It’s the baseline efficiency for Energy Star certification. It shows up in a variety of ways in other parts of the energy sector.
CalGreen calls its first voluntary level Tier I, but it means much more than just being 15% better than Title 24. In order to achieve Cal Green Tier I performance, you also have to meet additional requirements, summarized in Table 1.
In Planning and Design, you have to stockpile, protect, and reuse displaced topsoil. At least 20% of the project hardscapes have to be permeable surfaces, and roof coverings must be certified cool-roof material. As I’ve already mentioned, in Energy Efficiency, you have to exceed Title 24 by 15% as determined by a modeling calculation. That can involve improvements to many aspects of the building, including the envelope, shell leakage, insulation levels, mechanical equipment efficiencies, passive-solar design, and more (renewables are currently excluded from those calculations). To meet Tier I Water Efficiency thresholds, kitchen faucets cannot exceed 1.5 gpm, and landscape designs have to reduce the use of potable water by 35% (that’s a slight simplification of the actual calculation). In the Material Conservation category, you have to reduce concrete use by at least 20%, with additives like fly ash, and use at least 10% recycled materials, by cost, with postconsumer content weighed more heavily than postindustrial content. You have to reduce construction waste by 65%. Finally, in Environmental Quality, at least 80% of installed resilient flooring and all insulation must meet specific VOC levels.
Once you meet the Tier I prerequisites, you still have to select a certain number of electives in each category (the exact numbers are shown in Table 4). The electives cover a wide range of options. For instance, Planning and Design options include disassembling and reusing or recycling existing buildings, passive-solar orientation, and limiting turf. Energy Efficiency electives include radiant barriers, west- and south-facing window shading, blower door and duct testing, an HVAC commissioning plan, mechanical equipment efficiencies, renewables, and much more. Many of the efficiency electives affect a project’s Title 24 calculation, letting you kill two birds with one stone. For instance, a good passive-solar design can radically improve your Title 24 score. The same is true for duct and blower door testing. By selecting these types of measures, you can satisfy both the Tier I percentage threshold and the Energy Efficiency elective requirements. You can meet the Water Efficiency elective requirements by reducing potable irrigation water use, rainwater capture, and graywater and recycled-water systems. Material Conservation electives include a variety of framing efficiency measures, low-maintenance materials, and moisture management measures. Environmental Quality electives are limited to meeting stricter formaldehyde requirements, greater than MERV 6 filters, and having no direct-vent appliances in conditioned space.
Tier II takes selected Tier I electives and makes them mandatory. In addition, Tier II also requires more electives than Tier I, from what is now a smaller pool, since some former electives are now prerequisites. Some of the Tier II requirements, summarized in Table 2, are similar to Tier I with higher thresholds; others are brand-new. The CalGreen reference guide warns that it’s difficult to achieve Tier II and suggests that local jurisdictions think carefully before making it mandatory.
In Planning and Design, in order to reach Tier II, you have to protect the topsoil (as required for Tier I), plus delineate the construction area with fencing or flags to protect it from damage by machinery and other construction activities. You also have to have at least 30% permeable hardscape (instead of 20% for Tier I) and cool-roof specifications that are more stringent than those for Tier I. For Energy Efficiency, you have to exceed Title 24’s baseline by 30% instead of 15%. In the Water Efficiency category