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Chimney height and combustion plant emissions

Date updated: 11/08/2023

Combustion plant emissions​

As part of several measures to minimise emissions of air pollutants from combustion plant, all newly installed boilers and Combined Heat and Power (CHP) Plant must meet low NOx emission​ limits - see the Air Quality Supplementary Planning Document for more guidance.

The City of London Corporation has produced best practice guidance aimed at minimising emissions from combustion plant:

Combustion plant best practice recommendations PDF (1.1MB)
Date submitted: 9/12/20
For operators: how to use the best practice guidance PDF (170KB)
Date submitted: 9/12/20

Proposed New powers

The City Corporation has developed proposals for new powers for London local authorities to manage emissions from a range of combustion plant. The proposals are in the Emission Reduction (Local Authorities in London) Bill.

Chimney height approvals

A chimney serving commercial or industrial furnaces or boilers, used to burn the following fuels, must obtain approval from the City Corporation before it is used. This is to ensure that the proposed chimney is high enough to allow adequate dispersion of the flue gases. 

  1. Pulverised fuel
  2. Any other solid matter at a rate of 45.4 kilograms/hour or more.
  3. Any liquid or gaseous matter at a rate of 366.4 kilowatts/hour or more

The City Corporation will determine the application within 28 days of receipt. There is no charge.

Chimney height approval is in addition to any other necessary permissions, e.g.​ planning permission or building regulation approval.

Please return the completed Chimney Height Application Form to the Air Quality team using the contact button.

Chimney Height application form PDF (46KB)
Date submitted: 14/01/20Contact Air Quality team