Summary and critique of LEED 2.2 New Construction Reference Guide

Jonathan Ochshorn

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8. Glossary: selected terms only

Following is my selective summary of the "Glossary" section of the LEED 2.2 New Construction Reference Guide, Second Edition, Sept. 2006. My commentary on the Reference Guide can be found in the red boxes within each of the chapters linked immediately above.

Albedo: Solar reflectance = ratio of reflected solar energy to incoming energy measured over wavelengths from 0.3 - 2.5 micrometers. For this spectrum, 1.0 or 100% represents complete reflection (perfect mirror).

Aquatic systems: These are a kind of wastewater treatment system that uses biological organisms (bacteria, plants, fish) to treat wastewater to advanced levels.

Assembly recycled content: Divide the weight of an assembly's recycled content (including both post- and pre-consumer elements) by the assembly's total weight.

Baseline building performance: First, one defines a "baseline" building; then one computes the annual cost of energy use for that building. Both aspects are defined in ASHRAE 90.1-2004, especially Appendix G. The idea of a "baseline" is to establish a fictitious building design that represents some sort of normative condition, i.e., an ordinary building that meets only minimal industry or code standards.

Bioremediation: For contaminated sites, this refers to a process, generally on site, that uses microorganisms or vegetation to clean up the contaminants.

Blackwater: Codes differ on what constitutes blackwater. In general, it consists of wastewater from toilets and urinals, but also possibly from kitchen sinks and showers. Not to be confused with the security outfit of the same name.

BOD: Basis of design.

Breathing zone: A zone within interior spaces used to measure interior air quality: between three and six feet above the floor, at least two feet from walls, and away from HVAC equipment.

Building density: Divide the total floor area of the building by the site area, using square feet per acre units.

CERCLA: Stands for the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, popularly known as the "superfund."

Chlorofluorocarbons: CFCs were commonly used as refreigerants; they deplete the ozone layer.

Cogeneration: A type of power generation that simultaneously produces electrical/mechanical energy and thermal energy; i.e., power and heat.

Completed design area: A very specific and idiosyncratic LEED measurement for the calculations relating to building reuse credit: it includes the total areas of completed ceilings, floors, full-height walls, demountable partitions, and built-in case goods; but excludes exterior doors and windows. Note that the prior condition area is similarly defined, but refers to the building condition before project work was undertaken.

Composite wood: Any of a series of products in which wood is bonded with synthetic resins or binders to create things like plywood, OSB, MDF, particle board, and various door cores. LEED only "regulates" such products when they are part of the interior.

Development footprint: Essentially consists of the building and site hardscape (roads, pavement, paths).

Embodied energy: The total amount of energy used in the life cycle of a particular commodity, including energy needed for manufacture, transport, and disposal.

Emissivity: For an object, divide the radiant energy emitted from its surface by the radiation that would be emitted from an equivalent surface of a so-called "black body" at the same temperature.

Energy Star Rating: A joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy designed to encourage energy-efficient products and practices.

Flat coatings: For paint, where the measured gloss is less than 15 (85-degree meter) or less than 5 (60-degree meter).

Footcandle: (fc) 1 lumen on 1 square foot from 1 candela light source 1 foot away = illuminance.

Functional performance testing: (FPT) This refers to the process of measuring the performance of commissioned systems according to the owner's project requirements (OPR), the basis of design (BOD), and the construction documents (CD).

Glazing factor: (GF) Divide the interior illuminance, measured on the work plane, by the exterior illuminance, measured on an overcast day. LEED's equation to calculate GF includes consideration of the floor area, window area, window geometry, window height, and visible transmittance through the window.

GWP: Global warming potential.

Greenhouse gases: CO2, methane, CFCs.

Hydrochlorofluorocarbons: (HCFCs) An alternative class of refrigerants, better than CFCs, but still tending to damage the ozone layer.

Hydrofluorocarbons: (HFCs) An alternative class of refrigerants that do not damage the ozone layer, but still may contribute substantially to global warming.

Emittance: Measures the ability to shed heat radiation (infrared or thermal) on a scale from 0 to 1. Note that 0.9 is a common value for ordinary building materials, except for metals, which generally have lower emittance.

Life cycle cost method: (LCC method) Measures cost by including not only purchase price, but also replacement costs, costs of operations (including energy), costs of maintenance and repair; subtracting any resale value; and expressed in present or annual value.

Life cycle inventory: (LCI) Includes all energy and waste associated with a particular product, measured from the time of the product's creation until its disposal.

Non-occupied space: Basically refers to maintenance space, as opposed to non-regularly occupied space which also includes things like corridors, copy rooms, and so forth.

ODP: Ozone depletion potential.

OPR: Owner's project requirements.

RCRA: Resource Conservation and Recovery Act of 1976 gave the federal EPA authority to control hazardous wastes.

RECs: Renewable energy certificates "(also known as green tags, green energy certificates, or tradable renewable certificates) represent the environmental attributes of power generated from renewable electric plants. A variety of organizations offer RECs separate from electricity service, that is, you need not switch from your current electricity supplier in order to purchase these certificates." (see U.S. Dept. of Energy green power web site).

Solar reflectance: see albedo.

Solar reflectance index: (SRI) A scale that measures ability to reject solar heat, with standard black = 0, and standard white = 100 (so that it is possible for a material to exceed 100 if more reflective than standard white).

Tertiary treatment: This refers to the highest level of wastewater treatment.

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