In § 19, para. 1, the BImSchV specifies in which roof areas the chimney mouth is inadmissible for solid fuels in order to minimise harmful exhaust gas nuisances. The requirements apply to combustion plants that are built or significantly modified from 22.03.2010.
Roof pitch up to 20°: The mouth must exceed the ridge by at least 40 cm or be at least 1 m away from the roof surface (measured vertically!). For flat roofs, the following applies: The mouth must protrude from the parapet by 1 m:
Image: Prohibited areas for the chimney mouth at roof pitch up to 20° - bauwion
Roof pitch > 20°: The mouth must protrude from the ridge by at least 40 cm or be at least 2.30 m away from the roof surface (measured horizontally!):
Image: Inadmissible areas for the chimney mouth with roof pitch > 20° - bauwion
Regardless of the roof pitch, the following applies to the mouths of combustion systems up to 50 kW total heat output:
Ventilation openings, windows (including roof windows!) or dormers within a radius of 15 m around the chimney mouth must be at least 1 m towered over. The distances also apply to openings of neighboring buildings!
This distance of 15 m increases by 2 m for every additional 50 KW or part thereof, up to a maximum of 40 m.
Image: Inadmissible areas for the chimney mouth in relation to building openings and total heat output - bauwion
Source: bauwion
