Odour Assessment

In most cases, yes — particularly if the restaurant is near residential properties. The planning authority will want to see that the proposed kitchen extraction and odour control system is adequate to prevent odour nuisance to neighbours. The level of assessment depends on the type of cooking (charcoal grilling and deep frying generate more odour than light food preparation) and the proximity of sensitive receptors.

The IAQM Guidance on the Assessment of Odour for Planning (2018) is the primary technical guidance used in England for assessing odour impacts in the planning context. It provides a framework for determining the significance of odour effects based on the source odour potential, the pathway effectiveness (how far and how often odour travels), and the receptor sensitivity. It is widely adopted by local planning authorities and referenced in planning decisions.

Odour can be assessed using several methods. Source emissions can be measured through olfactometry — a laboratory technique where panellists smell diluted samples to determine the odour concentration in odour units per cubic metre (ouE/m3). In the field, 'sniff testing' involves trained assessors walking around the site and recording odour intensity, character, and extent at defined points. Dispersion modelling predicts odour concentrations at receptor locations using source emission rates and local meteorological data.

The appropriate extraction system depends on the type of cooking and the proximity of neighbours. The Defra guidance on the control of odour and noise from commercial kitchen exhaust systems classifies cooking processes by their odour potential (low, medium, or high). High-odour cooking such as charcoal grilling near residential receptors may require a multi-stage system incorporating grease filters, electrostatic precipitators, and carbon filters, with the extract discharged at high level above the roof ridge.

Absolutely. The NPPF requires that planning decisions ensure a good standard of amenity for existing and future occupants, and persistent or offensive odour can constitute a significant adverse impact on amenity. If the odour assessment demonstrates that unacceptable impacts cannot be mitigated, the application can be refused. Equally, retrospective complaints about odour from existing premises can lead to enforcement action and abatement notices.

An Odour Assessment is a predictive assessment carried out before development takes place, submitted with the planning application. A nuisance complaint is a reactive response to odour problems after a development is operational, investigated under the Environmental Protection Act 1990. The purpose of the planning-stage assessment is to prevent nuisance from arising in the first place. If odour control measures are inadequate despite the assessment, the council can take enforcement action.

Almost certainly. Waste management facilities — including recycling centres, composting sites, anaerobic digestion plants, and waste transfer stations — are significant potential odour sources. The Environment Agency requires odour management plans for permitted waste facilities, and the planning authority will require a detailed odour assessment demonstrating that the facility can operate without causing odour nuisance. Dispersion modelling is usually essential for waste facility applications.

The distance depends on the nature and strength of the source, atmospheric conditions, and local topography. Odour from a restaurant kitchen might be perceptible 20 to 50 metres from the discharge point in adverse conditions. Large industrial or agricultural odour sources can cause impacts at distances of 500 metres to several kilometres. Dispersion modelling takes account of these factors and predicts the frequency and concentration of odour at different distances.

An odour management plan (OMP) is a documented set of procedures for controlling, monitoring, and responding to odour emissions from a site. It typically includes descriptions of all potential odour sources, control measures in place, maintenance schedules for odour abatement equipment, monitoring protocols, complaint recording and response procedures, and contingency measures for abnormal conditions. OMPs are commonly required by planning condition or environmental permit.

Potentially, but an odour assessment will be essential. The Environment Agency and water companies typically recommend buffer zones around sewage treatment works, and most local planning authorities have policies addressing development near such facilities. The assessment must demonstrate that future residents will not experience unacceptable odour impacts. Mitigation might include increased separation distances, site layout design, or sealed windows with mechanical ventilation on the most exposed facades.