Eaves Vent Calculator
The ventilation requirements for the roof structure must be designed on a case-by-case basis as a basis for determining both the number and placement of ventilation vents. The calculator below provides a general recommendation regarding the minimum number of FB eave vents per floor area in a cold attic. The recommendations used as the basis for the calculator's calculations include those found in the book Brandsäkra Trähus, which is part of the Nordic Wood collaboration project (in which, among others, Byggforsk participates).
SINTEF Byggforsk Handbook 51 Fleretasjes trehus (Multi-story wooden buildings) also recommends that the ventilation area of cold attics/roofs should be 1/300 of the roof's/attic's floor area. This figure is based on the total ventilation area, including exhaust vents. The calculator indicates the recommended number of vents for intake air at the eaves corresponding to an area of 1/600 of the roof's floor area. Conventional ventilation at the gable ends is assumed. The 1/300 total and 1/600 for eave intake are the most common values used in other countries as well, for example by the Federal Housing Administration (FHA) in the USA.
For decimal numbers, use a period as the decimal separator.
SINTEF Byggforsk Handbook 51 Fleretasjes trehus (Multi-story wooden buildings) also recommends that the ventilation area of cold attics/roofs should be 1/300 of the roof's/attic's floor area. This figure is based on the total ventilation area, including exhaust vents. The calculator indicates the recommended number of vents for intake air at the eaves corresponding to an area of 1/600 of the roof's floor area. Conventional ventilation at the gable ends is assumed. The 1/300 total and 1/600 for eave intake are the most common values used in other countries as well, for example by the Federal Housing Administration (FHA) in the USA.
For decimal numbers, use a period as the decimal separator.
