Window cleaning. The design of the building must include
Replacement of windows in historic structures should
provisions for cleaning the interior and exterior surfaces
exactly match original frame and munton profiles. First
of all windows. Window washing systems used in the
consideration should be given to rehabilitating the
region must be considered and a preferred system and
existing windows.
equipment identified during design. In large and/or high-
Consideration of glare control plus heating and cooling
rise buildings, such glass surfaces as atrium walls and
loads must be factored into decisions on amount and
skylight, sloped glazing, pavilion structures, and windows
placement of windows.
at intermediate design surfaces must be addressed. See
Aluminum windows shall meet the requirements of
also the Building Specialties, Window Washing Equipment
ANSI/AAMA Standard 101-85. Only Optional
section of this chapter.
Performance Classes may be used. Metal windows other
than aluminum shall meet the requirements of the
National Association of Architectural Metal
Manufacturers Standard SW-1 for the performance class
required. Wood windows should meet the requirements of
ANSI/NWMA Standard I.S. 2-87, Grade 60.
Aluminum frames must have thermal barriers where there
are more than 1670 heating degree days C (3,000 heating
degree days F). Window mullions, as much as possible,
should be located on the floor planning grid to permit the
abutment of interior partitions.
Glazing. The choice of single, double or triple glazed
windows should be based on climate and energy
conservation and security requirements. Use thermally
broken frames when double and triple glazing units are
specified. Highly reflective glass that produces mirror
images should be used with care to avoid creating glare
in surrounding streets and buildings.
condensation resistance factor (CRF) adequate to prevent
condensation from forming on the interior surfaces of the
windows. The CRF can be determined by testing in
accordance with AAMA 1502.7, Voluntary Test Method for
Condensation Resistance of Windows, Doors and Glazed
Wall Sections. Where a CRF in excess of 60 is required, do
not use windows unless some condensation can be
tolerated or other methods are used to prevent or remove
condensation.
Robert C. Byrd Courthouse, Charleston, WV
83
ARCHITECTURAL
AND
INTERIOR
DESIGN
3.5
Building Elements
Revised March 2005 PBS-P100
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