beled, vent to the exterior, and be controlled by a humidistat unless they are part of a whole-house ventilation system. Whole-house exhaust fans must have covers or louvers that are insulated to at least R-4.2. HVAC systems must be designed using ACCA Manual J, D, and S methodologies or equivalents.
Only one of the mandatory requirements requires onerous documentation—the building operations and maintenance manual. It’s my experience that the highest-quality builders of, typically, custom homes, always assemble an O&M manual for their homeowners. This will be a burden for production builders and builders of other lower-end structures, at least the first time around. It should be easy to develop a template that can be readily adapted to multiple projects without too much work. Although the construction waste requirement seems like a pain, all the jurisdictions I work within, spanning five counties, already have a 50% minimum waste diversion requirement and landfill documentation that makes it pretty easy to track. It’s unlikely that anyone will have to develop their own unique waste diversion plan. If so, CalGreen includes a sample plan and associated work sheets.
The requirement that I think will irritate some folks is that HVAC systems have to be designed using ACCA Manual J, D, and S. The only place I see designed mechanical systems is on some high-end houses. Most HVAC contractors do what are called field design systems, a great euphemism for “seat of the pants.” They don’t know or care about ACCA, they don’t have the certified software, and they don’t have the time or interest to do a formal design. It will be interesting to see how that part of the code evolves.
Tier I is the lower of the two voluntary CalGreen code levels. The tier system permeates many of California’s energy-related mandates. Tier I is defined by the investor-owned utilities, the California Energy Commission, and other parties as 15% over the current Title 24, which is updated approximately every three years. Tier I is the minimum requirement 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 barrier