This credit rewards project buildings that exceed the requirements specified in WEp1: Minimum Indoor Plumbing Fixture and Fitting Efficiency.  Additional points are earned if the performance calculations indicate that indoor potable water usage is at least 10% less than indicated in the credit baseline. Projects may be awarded an innovation point for exemplary performance by achieving a potable water savings of 35% or greater.

To earn this credit, you’ll need to reduce your use of potable water for irrigation by 50%–100% compared with a baseline irrigation system typical for the region. Because landscape irrigation can account for nearly 40% of the average office building’s potable water consumption, reducing or eliminating potable water use for landscaping can save a lot of water, and money.

Mitigating 15% of stormwater for this credit may be more doable than you think. If a site was not designed with stormwater mitigation in mind, or does not have the benefit of extensive vegetated areas relative to the amount of impervious site area, you may need to make a significant investment in strategies like cisterns, green roofs, water retention features, and detention ponds.

This prerequisite requires you to write a sustainable purchasing policy to establish guiding principles for the purchase of environmentally preferable products and materials when economically feasible.  Switching to environmentally preferable purchasing (EPP) may ultimately add costs for some purchases, but project teams can determine on a product-by-product basis whether the environmentally-preferable option is cost-effective. This EPP policy can be created by in-house staff without any capital investment.

Fluorescent lamps are one of the most affordable, efficient, and common lighting technologies. Along with metal halide and other gas-discharge lamps, however, they contain mercury, a toxic element that contributes to water pollution and poses significant human health risks. Use of low-mercury fluorescent lamps, or other mercury-free lighting  technologies, reduce the risk of mercury exposure in buildings from broken lamps, and reduces overall mercury consumption. (Don’t let the reduced mercury lull you into complacency about safety in use and disposal, however.)

Meeting the LEED ventilation prerequisite is not likely to require substantial building upgrades, although it is likely to require some adjustments, such as altering minimum damper settings on existing equipment.

Prohibiting smoking indoors is the most efficient and cost-effective way to achieve this prerequisite. The key to this approach is to establish a building-wide policy prohibiting smoking indoors and within 25 feet of the building’s entrances, outdoor air intakes, and operable windows. These policies can be enforced through strategic placement of cigarette receptacles, signage indicating where smoking is prohibited, and passive discouragement of smoking near the building openings.

Addressing both interior and exterior lighting, this credit seeks to reduce light pollution that can block our view of the night sky and cause human health problems as well as ecological problems for many birds, insects, and other animals. Light pollution often represents nighttime lighting that isn’t needed and that may cause light trespass and contrast, reducing visibility.