NCC 2025
NCC 2022
Vent Calculator
Calculate ridge, facia and barge/parapet vents for your roof
Type of roof:
Select roof type
Tile
Metal
Roof cavity:
Select roof cavity
Truss roof
Cathedral roof
Pitch direction:
Pitched (two-sided)
Mono pitched (single slope)
Roof angle:
Select roof angle
Less than 10°
10–15°
15–75°
BAL rating:
Select BAL rating
Non Bal
Bal 12.5
Bal 19
Bal 29
Bal 40
Bal FZ
Ridge — length of longest side of roof in meters (LS):
Facia length (including box gutters) in meters:
Barge/Parapet/Abutment lengths in meters:
Calculate Vents
Result:
Vent Calculator
Calculate ridge, facia and barge/parapet vents for your roof
Roof size:
Select roof size
≤ 10m²
> 10m²
Type of roof:
Select roof type
Tile
Metal
Roof cavity:
Select roof cavity
Truss roof
Cathedral roof
Pitch direction:
Pitched (two-sided)
Mono pitched (single slope)
Roof angle:
Select roof angle
Less than 10°
10–15°
15–75°
BAL rating:
Select BAL rating
Non Bal
Bal 12.5
Bal 19
Bal 29
Bal 40
Bal FZ
Ridge — length of longest side of roof in meters (LS):
Facia length (including box gutters) in meters:
Barge/Parapet/Abutment lengths in meters:
Calculate Vents
Result:
