Chimney Pots and Cowls: Anti-Downdraught Cowls, Bird Guards, Rotating Types and When Each Is Needed
Anti-downdraught cowl types (H-cowl, lobster-back, louvred, rotating); bird guard mesh types; Part J:2022 terminal height requirements (1 m above ridge / 2.3 m above penetration); solid fuel free area = 4× flue cross-section; balanced flue cowl warning; planning permission for listed buildings