Glossary 201pants giving light to surfaces and objects within a space. This has parti-
cular relevance in churches.
Innovative daylighting Methods of daylight admission to a building
which take advantage of a new technology: examples being Light
Shelves, Light Pipes, or heliostates etc.
Interactive window A prototype window design, combining the
requirements of daylighting and view, with those of solar control, and
ventilation, thermal and sound insulation and the elimination of glare.
Light penetration See daylight effective depth.
Light pipes A form of rooflight associates with mirror finished ducts
which direct natural light and sometimes ventilation into lower floors of
the building.
Light shelves A horizontal construction at the window designed to
reflect light to the ceiling, to assist in increasing the daylight penetration
into the room
Low emissivity glass Glass where the radiating power of heat or light is
reduced
No sky-line The demarkation line within a building where, due to
external obstruction and window configuration, no view of the sky is
visible.
Obstruction/view The diminution of available light and view by other
buildings at a distance. View is an important environmental aspect of
daylight, which may be impaired by obstruction, but can sometimes be
overcome by attention to orientation.
Orientation The geographical relationship of a proposed building to its
site, enabling a strategic view to be gained of the possible daylighting
design.
Physical modelling The use of architectural models to provide a means
of calculating the daylight factors of a proposed building design. These
can be placed in an artificial sky or used externally. Physical modelling
has been found to mimic methods of computer calculation sufficiently
accurately with the added advantage of providing a visual impression of
the interior to the architect.
Photochromic glass Glass responding directly, to an environment sti-
mulus such as heat or light, which alters its transmission value
Prismatic panels Panels formed to alter the path of light, so as to redir-
ect it, either to cut out glare, or to introduce light for useful purposes
Rights of light Legislation which allows a building owner to preserve
the amount of natural light his building enjoys; likewise he must ensure
that his building does not obstruct the daylight enjoyed by his neighbour.
Shading/briese soleil The means adopted to prevent the deleterious
effects of solar gain from southern exposures; these may be external
structural louvres attached to the face of the building or forms of heliosc-
reen blind.
Sky glare The unacceptable contrast between the view of the sky out-
side, and the interior surfaces.