Environmental and health related criteria for buildings - ANEC

IBO - Environmental and Health related Criteria for Buildings
Conclusions Daylighting
Daylight factor requirements can be defined either as point or average daylight factor(s) (for
relevant rooms of dwellings) or averaged over the whole (or a defined percentage of the) net
floor area of a building. Optimisation strategies are more effective if rooms / dwelling units
are considered separately and the overall rating is based on an arithmetical mean value of
single scores of all dwelling units. Net floor area based ratings consider all rooms
independently of their functions and daylight requirements ignoring the fact that darker zones
are acceptable for retreat areas, corridors, bathrooms, etc.
The authors recommend to assess the geometric prerequisites of the building by defining a
minimum point daylight factor in living rooms (in order to ease verification) as well as
direct sunlight in the dwelling units (by using sun hours in winter-time) for the rating of
the visual quality of residential buildings.
As the calculation of daylight factors refers only to geometrical and surface-related data of
rooms without consideration of latitude, orientation and access to direct sunlight, the rating
has to be complemented by an indicator assessing the daylight availability on site. Sundrenched
rooms are one of the most important purchasing criteria for consumers. Access to
direct sunlight in dwelling units can be evaluated by parameters such as sun hours per day
especially in wintertime (at low positions of the sun). By these means, criteria like “views out”
and “direct sky light” are automatically fulfilled.
As for northern latitudes the optimization potential for winter sun is limited, it is recommended
to define regional benchmarks adapted to country-specific conditions.
Glare control (for balanced luminance distribution in the visual field) is of greater
significance for office buildings, rooms with workstations, schools, etc. and need not
generally to be integrated in a catalogue tailored for residential buildings (apart from mixed
use or southern European countries with higher solar radiation).
Lighting control is not considered to be an important indicator for residential buildings.
Final Report 103 31 03 2011