Green Building Guidelines & Standards
Background Information - Green Building Guidelines & Standards
There is a clear link between the efforts of the water efficiency community and the green building movement. Particularly in residential green building programs, a significant opportunity exists for partnership in areas of hot water plumbing design, high-efficiency plumbing fixtures and appliances, and outdoor landscaping and irrigation system design. Most green building initiatives focus on energy efficiency and sustainable materials construction. Water efficiency is not yet a prominent piece of many existing green building programs, although that has begun to change.
The U.S. Green Building Council (USGBC) has been a leader in the green building movement. Their LEED program (Leadership in Energy and Environmental Design) is the most prominent and well-known of the green building programs. There are, however, a number of other green building standards either extant or emerging.
Typical water use efficiency categories within many of the national green building programs (guidelines and standards) include:
- Plumbing fixtures and fixture fittings
- Residential appliances (clothes washers, dishwashers)
- Water treatment equipment (softeners, filtering systems)
- Landscape & landscape irrigation
- Pools, fountains, and spas
- Cooling towers
- Decorative and recreational water features
- Water reuse & alternate sources of water (graywater, rainwater and stormwater, cooling condensate and cooling tower blowdown, foundation drain water)
- Specialty processes, appliances and equipment (food service, medical, laboratories, laundries, others)
- Metering & submetering
- Once-through cooling
- Vegetated green roofs
- Building water pressure
Green building water conservation strategies under LEED and other similar programs typically fall into five categories:
- Efficiency of potable water use through better design/technology (fixtures, appliances, processes, equipment, HVAC, and other systems).
- Capture of gray water – non-fecal waste water from lavatory sinks, bathtubs, showers, washing machines, etc. – and use for irrigation.
- On-site storm water capture for use or groundwater recharge.
- Rainwater capture and reuse.
- Recycled/reclaimed water use, including on-site treatment of non-potable water.
Green Building Guidelines: USGBC - LEED Program
The USGBC estimates that a 30% indoor and a 50% outdoor water savings is possible and commonly achieved. Irrigation and Indoor Water Use Reduction were two of the most common “credits” earned by LEED aspirants, due largely to the ‘ease’ with which the indoor credits could be obtained. This was due, in part, to the fact that LEED allowed baseline faucet flow rates in VIOLATION of the model plumbing codes and national standards, thereby making water use ‘reductions’ from a false baseline water use relatively easy! LEED failed to recognize that the national standard (incorporated by reference into the codes) provided for a 0.5 gpm flow rate for non-residential lavatory faucets. The USGBC finally acknowledged that they had made an error in earlier versions of LEED and finally corrected this mistake in LEED 2009.
In addition to correcting the baseline water use error in 2009, LEED also incorporated a pre-requisite into their system that called for a 20 percent reduction in indoor water use before earning any LEED credits. This one significant measure made water use efficiency a high priority item within LEED.
National Green Building Standards
It is important to understand the difference between green building standards and green building guidelines. While guidelines provide thresholds for efficiency, they are not generally written in code-adoptable language, and compliance is usually voluntary. Standards, on the other hand, provide definitive efficiency thresholds, are written in language that is enforceable, and are readily adopted by reference into codes and other regulations as mentioned above.
For example, the well-entrenched LEED Program consists of a set of guidelines that designers and builders may voluntarily choose to comply with (although some jurisdictions are choosing to mandate compliance with LEED to some level and use credits as the measure of compliance). As such, these guidelines are not generally written in language suitable for direct adoption or reference as codes or other regulations.
Currently, national green building standards include these initiatives, each of which was or is being developed through the ANSI (American National Standards Institute) consensus process as an American National Standard:
- ASHRAE ANSI Standard 189.1 Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings
- Green Globes-Green Building Initiative (GBI) ANSI Standard 01-2008: Green Building Assessment Protocol for Commercial Buildings
- ASHRAE Proposed ANSI Standard 191 - Standard for the Efficient Use of Water in Building, Site and Mechanical Systems
Comparisons of the provisions of these three ANSI standards with the requirements of the model ‘green’ codes are shown in the following four tables:
Alliance for Water Efficiency White Paper - The Status of Legislation, Regulation, Codes & Standards on Indoor Plumbing Water Efficiency
This white paper discusses the status of various indoor plumbing efficiency codes and standards. It advocates for uniformity across the U.S. in earning indoor water efficiency points within all green codes, standards, and rating systems. This paper encourages legislators, regulators, and codes and standards developers to incorporate higher minimum performance and efficiency requirements for indoor plumbing into legislative, regulatory, and codes and standards initiatives.
U.S. National Efficiency Standards (fixtures and appliances)
The following link navigates to a PDF document that lists National Efficiency Standards for 14 water-using fixtures and appliances. The document also lists specifications for WaterSense®, ENERGY STAR®, and the Consortium for Energy Efficiency, and includes links to related resources.
U.S. “Green” Specifications for Indoor Fixtures and Appliances
Various “green” standards and guidelines exist for plumbing fixtures and appliances beyond the U.S. National Standards. These standards and guidelines may be part of voluntary programs such as WaterSense Single-Family New Homes and USGBC LEED for Homes, or codes such as the IAPMO Green Plumbing and Mechanical Code Supplement and the ICC International Green Construction Code. The linked PDF below contains information on specifications for a variety of standards, codes, and voluntary initiatives.
Appliance Industry and Efficiency Organizations Agree on New Standards
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