Page 469 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

Definitions 429

Retained Components ‘The portions of the finished ceilings, finished floors, full-length walls
and demountable partitions, interior doors, and built-in case goods that existed in the prior
condition and remained in the completed design.’
Reuse ‘A strategy to return materials to active use in the same or related capacity.’

Risk Assessment ‘A methodology used to analyze for potential health effects caused by
contaminants in the environment. Information from the risk assessment is used to determine
cleanup levels.’
Salvaged Materials ‘Construction materials recovered from existing buildings or construction
sites and reused in other buildings. Common salvaged materials include structural beams
and posts, flooring, doors, cabinetry, brick and decorative items.’
Sealant ‘Any material with adhesive properties that is formulated primarily to fill, seal or
waterproof gaps or joints between two surfaces. Sealants include sealant primers and caulks.’
Sedimentation ‘The addition of soils to water bodies by natural and human-related activities.
Sedimentation decreases water quality and accelerates the aging process of lakes, rivers and
streams.’
Shared (Group) Multioccupant Spaces ‘Conference rooms, classrooms, and other indoor
spaces used as a place of congregation for presentations, trainings, etc. Individuals using
these spaces share the lighting and temperature controls, and they should have, at a
minimum, a separate zone with accessible thermostat and an airflow control.’
Shielding A nontechnical term that describes devices or techniques that are used as part of
a luminaire or lamp to limit glare, light trespass, and light pollution (as per LEED-NC 2.1).
Site Area Same as Property Area.
Site Assessment ‘An evaluation of aboveground (including facilities) and subsurface
characteristics, including the geology and hydrology of the site, to determine if a release has
occurred, as well as the extent and concentration of the release. Information generated
during a site assessment is used to support remedial action decisions.’
Solar Reflectance (Albedo) (As defined in SSc7.2) ‘Ratio of the reflected solar energy to the
incoming solar energy over wavelengths of approximately 0.3 to 2.5 μm. A reflectance of
100 percent means that all the energy striking a reflecting surface is reflected into the
atmosphere and none of the energy is absorbed by the surface. The best standard technique
for its determination uses spectrophotometric measurements with an integrating sphere to
determine the reflectance at each different wavelength. An averaging process using a standard
solar spectrum then determines the average reflectance (see ASTM Standard E903).’

Solar Reflectance Index (SRI) ‘A measure of the constructed surface’s ability to reflect solar
heat, as shown by a small temperature rise. It is defined so that a standard black (reflectance
0.05, emittance 0.90) is 0 and a standard white (reflectance 0.80, emittance 0.90) is 100. To
calculate the SRI for a given material, obtain the reflectance value and emittance value for
the material. SRI is calculated according to ASTM E 1980-01. Reflectance is measured
according to ASTM E 903, ASTM E 1918, or ASTM C 1549. Emittance is measured according
to ASTM E 408 or ASTM C 1371. Default values for some materials will be available in the
LEED-NC 2.2 Reference Guide.’ Some example values are also available in the LEED 2009
Reference Guide.
For example, a standard black surface has a temperature rise of 90°F (50°C) in full sun, and
a standard white surface has a temperature rise of 14.6°F (8.1°C). Once the maximum rise of