Small scale food manufacturing in a light industrial unit

Food manufacturing unit planning permission turns on one question: whether the process you want to run can be carried out in any residential area without detriment to the amenity of that area. That is the wording of Class E(g)(iii) of the Town and Country Planning (Use Classes) Order 1987 as amended, and it is a test about the process rather than about the product. A small bakery mixing and proving by day can pass it. The same bakery running ovens from 2am with a roof-mounted extract and three chilled deliveries before 6am cannot, and that puts it in Class B2 general industrial.

Light industrial use against general industrial use

Class E(g) covers three uses that can be carried out in a residential area without detriment to amenity: offices, research and development, and industrial processes. Class B2 is the use of land or buildings for an industrial process other than one falling within Class E(g).

So the dividing line is not a floorspace figure, a product type or a standard industrial classification code. It is the character of the process in amenity terms, assessed on the particular equipment, hours and servicing arrangements proposed.

That has a useful consequence. The same unit can lawfully be used for food production by one operator and not by another, because the test attaches to the use rather than to the building. It also means the description of development and the conditions matter enormously, since a permission for Class E(g)(iii) food production with specified plant is a narrower thing than an unrestricted E(g) consent.

Part 3 of Schedule 2 to the General Permitted Development Order 2015 permits certain changes between general industrial, storage and the Class E(g) uses, with floorspace limits in places. Those classes have been amended repeatedly, so read the current wording rather than relying on a summary.

The test that keeps a use within a residential area

Work through it as the officer will, equipment by equipment.

The process itself. Mixing, proving, chilling, portioning and packing are generally quiet and odourless. Frying, roasting, char-grilling, smoking, baking at volume, and anything involving solvents or boiling stock are not.

The plant the process needs. Extraction, refrigeration condensers, compressors, blast chillers and steam generators all run outside the building or vent through it, and they run when the process runs.

The servicing pattern. Chilled vehicles with their refrigeration units running, early collections, pallet handling and waste removal are amenity impacts in their own right.

The hours. A process that would be acceptable between 8am and 6pm may be unacceptable at 4am with no change to the equipment at all.

Where any of those four pushes the use beyond what a residential area could absorb, the honest answer is that it is Class B2 and needs a change of use application to a B2 unit on an industrial estate. Trying to squeeze a plainly industrial operation into an E(g) label produces an enforcement notice later. The use class question comes up in gentler forms too, as our note on community cafes and social enterprises and the use class question shows.

Odour and cooking emissions from production scale equipment

Production equipment is not catering equipment, and an extract system sized for a restaurant kitchen will not do. The council's environmental health officer will want the system specified, the discharge point justified and the abatement explained.

A Ventilation and Extraction Statement should give the extract volume flow rate, the duct route and the termination height and position relative to openings and nearby residential windows, the abatement train, the fan specification with its acoustic data, and the maintenance regime. Discharge at or above roof level, away from openable windows and at a velocity that disperses rather than deposits, is the baseline expectation.

Abatement options scale with the risk. Grease filtration alone for low odour processes, activated carbon for moderate odour, electrostatic precipitation plus carbon for high odour frying or roasting, and ultraviolet or ozone treatment where the supplier can evidence performance. The Defra guidance on control of odour and noise from commercial kitchen exhaust systems sets out a risk-based method that councils apply well beyond restaurants.

Where the odour risk is high, or where a residential window is within a short distance of the proposed discharge, an Odour Assessment using recognised exposure criteria is worth commissioning rather than arguing the point by assertion. Councils expect a suitably qualified author for odour work and professional review is strongly advised.

Trade effluent, grease and drainage capacity

Food production generates effluent a domestic drainage system was not designed for. Discharging trade effluent to a public sewer needs the sewerage undertaker's consent under the Water Industry Act 1991, and that consent is separate from planning permission and from the food hygiene registration.

Planning engages where the discharge affects sewer capacity or where the drainage strategy has to change. A Foul Sewage Assessment should state the daily volume, the strength of the effluent, the pre-treatment proposed and the undertaker's response to a capacity enquiry.

Fats, oils and grease are the practical problem. A grease trap or a grease recovery unit sized for the production volume, with a documented emptying regime, is what the undertaker asks for, and the unit takes floor space that has to appear on the layout drawing. Starch-heavy and dairy processes also produce high strength effluent that may need balancing or dosing before discharge.

Get the capacity enquiry in early. A refusal of trade effluent consent after planning permission has been granted leaves you with a lawful use you cannot operate.

Refrigeration plant noise and condenser siting

Refrigeration is the most common reason these applications are refused, and it is almost always a siting problem rather than a plant problem.

Condensers are tonal, they run through the night, and a background sound level measured on a quiet industrial estate at 2am is low. Assessment under BS 4142:2014+A1:2019 compares the rating level, with penalties for tonality and intermittency, against that background, and a unit that would be inaudible by day can exceed it comfortably at night. A Noise Impact Assessment is normally a validation requirement where any new plant is proposed.

The fixes are ordinary. Move the condenser to the elevation away from the nearest dwelling. Put it at ground level behind an acoustic screen rather than on the roof. Specify larger, slower fans. Add an acoustic enclosure or attenuated louvres. Accept a night-time setback where the process allows.

Design the plant location into the layout at the start. Retro-fitting mitigation onto a condenser already positioned on the boundary elevation is the expensive path, and it rarely performs as well as the calculation suggests.

Deliveries, chilled vehicles and yard activity

The yard is where the amenity case is usually lost. Reversing alarms, roller shutters, pallet trucks on a concrete apron and a refrigerated trailer idling for twenty minutes are all audible well beyond the site.

Show the servicing arrangement properly: the vehicle types and sizes, the number of movements by day type, the arrival and departure windows, the swept paths showing vehicles entering and leaving in forward gear, and the loading position relative to the nearest residential boundary. A Transport Statement covers the highway side, and many councils will also ask for a delivery and servicing plan setting out how the yard is managed.

Practical mitigation that councils accept includes broadband reversing alarms instead of tonal ones, a requirement that refrigeration units are switched off while loading, loading within the building where the unit allows, and surfacing that does not amplify pallet truck movements.

Conditions on hours, plant and process type

Expect a tight condition set, and expect it to be the thing you live with for years.

The conditions commonly imposed cover hours of operation, with separate and earlier-ending hours for deliveries and collections. Restriction of the use to Class E(g)(iii) with the specific process described, which removes the usual flexibility within Class E. A plant noise limit expressed as a rating level relative to measured background at a defined assessment position. Installation and ongoing maintenance of the approved odour abatement, with a service record available on request. No external storage of materials or waste. And approval of the final plant specification before installation.

Negotiate the hours against your actual production schedule with headroom, because varying them later needs a section 73 application. And read the use class restriction carefully: a condition tying the permission to one named process can block a change of product line that would otherwise need no consent at all.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval. Enter your postcode on PlanScope to see which reports your site needs.