has to be filtered and routed to a public drainage system. The new residential structure has to also comply with local storm water ordinances. The drainage system has to be shown on the site plan (swales, drain piping, retention areas, ground water recharge). CALGreen does not regulate energy efficiency (both for residential and non-residential structures), instead remanding it to the California Energy Commission (CEC) and its California Energy Code. Concerning the water issue, the code requires a 20% reduction of indoor water use and it uses both a prescriptive and performance method. The prescriptive method provides some technical features that have to be followed: Showerheads ≤ 2.0 gpm (gallons per minute) @ 80 psi Lavatory faucets ≤ 1.5 gpm @ 60 psi Kitchen faucets ≤ 1.8 gpm @ 60 psi Urinals ≤ 0.5 gal/flush Waterclosets ≤ 1.28 gallon effective flush rate The performance method uses the performance calculation worksheets in Chapter 8 (or other calculation acceptable to the enforcing agency). CALGreen also specifies acceptable performance standards for plumbing fixtures with reduced water usage. Fixtures can be installed if they meet standards listed in Table 4.303.3. Also outdoor water usage is regulated: the Code requires irrigation controls to be weather- or soil moisture-based and automatically adjust irrigation in response to changes in plants' needs as weather conditions change, or have rain sensors or communication systems that account for local rainfall. About construction waste reduction, disposal, and recycling, the code says that at least 50% of nonhazardous construction and demolition debris have to be recycled and/or salvaged. This has to be done through the development of a waste management plan submitted for approval to the enforcing agency. CALGreen Appendix A4 contains the voluntary measures (Tier 1 and Tier 2) that were developed in response to numerous stakeholder requests for a statewide method of enhancing green construction practiced beyond the Code's minimum levels. To meet Tier 1 or Tier 2, designers, builders, or property owners must increase the number of green building measures and further reduce percentages of water and energy use and waste to landfills in order to meet the threshold levels for each tier (these measures are listed in Section A4.601.4.2 (Tier 1) and Section A4.601.5.2 (Tier 2)). Also for non-residential structures CALGreen demands 20% savings of potable water, standards for plumbing fixtures and fittings, a construction waste management plan, and a construction reduction waste of at least 50%. The Code