Biomass Guidance

Biomass boilers are seen as a carbon neutral solution to modern heating demands.  A properly installed, well maintained unit with suitable fuel will clearly have a number of environmental advantages.

However, biomass burning can lead to increased emissions of particulates due to the combustion process.  In addition, in comparison to conventional gas burning, biomass can lead to an overall increase in emissions of nitrogen oxides.  In certain areas, this can be a problem as the increase at ground level could lead to local exceedances of the air quality objectives.

Several factors can influence this, including the type of fuel, moisture content of the fuel, emission rating of the boiler and its location. If the boiler is proposed near to an existing Air Quality Management Area, or if it is located in an area where monitoring indicates levels are approaching the air quality objectives, or areas where the existing background of particulates is high, the risk of an exceedance increases.

Developers might like to review the guidance document on Installing Biomass Heating Systems (PDF, 334KB) produced by 4NW.

What information is required?

In addition to the Planning Guidance, if your scheme includes a Biomass Heating Plant with a rating between 50kW and 20MW, we need you to complete the form below (if the proposed installation is over 20MW it will be subject to Environmental Permitting)

The above information must accompany any planning application.

Small Biomass Boiler

Guidance from the Environment Agency states that the Environment Agency has assessed the pollution risks and have concluded that air emissions from small biomass boilers are not likely to pose a significant risk to the environment or human health providing certain conditions are met.

Therefore a quantitative assessment of air emissions will not be required where:

• The fuel will be derived from virgin timber, miscanthus or straw, and;

• The biomass boiler appliance and installation meets the technical criteria to be eligible for the Renewable Heat Incentive, and;

• The aggregate boiler net rated thermal input is:

A. less than 0.5MWth, or;

B. less than 1MWth where the stack height is greater than 1 metre above the roof level of adjacent buildings (where there are no adjacent buildings, the stack height must be a minimum of 3 metres above ground), and there are; no Special Areas of Conservation, Special Protection Areas, Ramsar sites or Sites of Special Scientific Interest within 500 metres of the emission point(s);

AND no National Nature Reserves, Local Nature Reserves, ancient woodlands or local wildlife sites within 100 metres of the emission point(s),


C. less than 2MWth where, in addition to the above criteria, there are no sensitive receptors within 150 metres of the emission point(s).

Chimney Height . . .

Secondly, you may require Clean Air Act approval for the chimney serving your appliance.  If this is the case, you will need to submit a formal request for Chimney Height Approval under the Clean Air Act 1993.

Important information regarding the Clean Air Act 1993

If you propose to install a biomass boiler in a Smoke Control Area, it is a legal requirement that you install an Exempted Appliance and burn only Authorised Fuels in that area.

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