Toolkits

Permitted Development on Farms: Your Complete Guide

Most farms have more development potential than their owners realise. Permitted development rights (PDR) allow a significant range of agricultural buildings, barn conversions, and commercial uses without a full planning application. But the rules are specific, and mistakes are costly. This guide sets out what's available, how each right works, and where the limits lie.

What Are Agricultural Permitted Development Rights?

Permitted development rights are grants of planning permission set out in legislation. They remove the need to apply for full planning permission for certain types of development, provided specific criteria are met.

For farms, the relevant legislation is the Town and Country Planning (General Permitted Development) (England) Order 2015, as amended. Schedule 2 sets out the permitted development rights available in different categories. The rights most relevant to farming are found in Part 6 (agricultural buildings and operations), Part 3 Class Q (agricultural to residential), and Part 3 Class R (agricultural to commercial).

Each right has its own set of conditions and limitations. Meeting the general description of the right is not enough. You must satisfy every condition attached to it.

The 2024 amendments — which came into force on 21 May 2024 — significantly expanded several of these rights. If you are working from guidance produced before that date, it may no longer be accurate.

Part 6: Agricultural Permitted Development Rights

Part 6 of Schedule 2 to the GPDO covers development on agricultural land as part of an agricultural trade or business. It is divided into two classes.

Class A: Agricultural Units of 5 Hectares or More

Class A applies to agricultural units of 5 hectares or more. It allows the erection, extension, or alteration of agricultural buildings, the formation of private ways, and certain engineering operations.

The most commonly used right under Class A is the erection of new agricultural buildings — grain stores, machinery stores, and similar structures. Prior approval is required for buildings over a certain size threshold. The local planning authority must approve the siting, design, and external appearance before work begins.

Following the May 2024 amendments, the floor area cap for new or extended buildings under Class A increased from 1,000 sq.m to 1,500 sq.m. This applies to non-livestock buildings. Livestock structures and engineering operations remain capped at 1,000 sq.m.

Class A no longer applies to land that is, or falls within the curtilage of, a scheduled monument. This restriction was introduced by the 2024 amendments.

Class B: Agricultural Units Between 0.4 and 5 Hectares

Class B applies to smaller agricultural units — those between 0.4 and 5 hectares. The range of permitted operations is narrower than Class A. New buildings are not permitted under Class B. The right covers extensions and alterations to existing agricultural buildings, and certain excavations and engineering operations.

If your farm is under 5 hectares, Class B is the relevant starting point. Many farmers on smaller holdings are unaware that their rights are more limited.

Class Q: Converting Agricultural Buildings to Homes

Class Q of Part 3 of Schedule 2 to the GPDO permits the change of use of an agricultural building to a dwelling house, along with associated building operations. The May 2024 amendments expanded this right considerably.

This is the right most enquiries to Foxes Rural relate to. It has significant potential — but it is tightly constrained.

What Class Q Allows

Class Q permits the conversion of qualifying agricultural buildings to up to 10 dwellings on a single agricultural unit. The maximum total floor space across all dwellings is 1,000 sq.m, and no individual dwelling can exceed 150 sq.m.

To create 10 dwellings at the maximum permitted, each would need to average 100 sq.m or less.

The 2024 amendments also introduced a single-storey rear extension of up to 4 metres, where hardstanding existed on or before 24 July 2023 or has been in place for at least 10 years.

Former Agricultural Buildings Are Now Eligible

One of the most significant changes in May 2024 was the extension of Class Q to former agricultural buildings — those that were once part of an established agricultural unit but no longer are.

Previously, the building had to be part of an active agricultural unit at the time of application. That requirement has gone. A redundant building that has left the unit can now qualify, provided it has not been used for any non-agricultural purpose since it ceased to be part of the unit.

In practice, this means isolated rural buildings that have sat unused for years may now have residential development potential. Evidence of agricultural use history remains essential.

The Key Test: Structural Suitability

The single most litigated issue in Class Q cases is whether the building is structurally capable of conversion without works that amount to a rebuild. Local planning authorities regularly refuse Class Q applications on the basis that the proposed works exceed what the right allows.

In our experience working with farmers and landowners across Essex and the East of England, the structural assessment is the document that determines whether a Class Q application succeeds or fails. A detailed structural engineer's report, prepared by someone who understands the planning context, is not optional.

Class Q Conditions You Must Satisfy

For buildings that are part of an established agricultural unit, the site must have been part of that unit on or before 24 July 2023. Where a building joined the unit after that date, it must have been part of the unit for at least 10 years before Class Q development begins.

Certain buildings are excluded. Listed buildings, scheduled monuments, and sites of special scientific interest do not qualify. Development on Article 2(3) land — which includes National Parks, Areas of Outstanding Natural Beauty, conservation areas, and World Heritage Sites — is not permitted under Class Q.

If a new agricultural building was erected on the unit under Part 6 Class A or Class B within the 10 years before a Class Q application is made, the right is not available. This is a condition that catches farmers who have recently built new sheds on the same unit.

Prior approval is required for all Class Q applications. The local authority assesses transport and highways impacts, noise, contamination, flood risk, location and siting, design and external appearance, and the provision of adequate natural light in habitable rooms.

Class R: Converting Agricultural Buildings to Commercial Uses

Class R of Part 3 permits the change of use of an agricultural building to a flexible commercial use. Following the May 2024 amendments, the permitted uses now include Class E (commercial, business and service uses) in addition to retail, cafés, offices, light industrial, non-residential institutions, and outdoor sport or recreation.

How Class R Works

The May 2024 amendments doubled the Class R floor area cap from 500 sq.m to 1,000 sq.m. This is a material increase and significantly expands the commercial diversification potential of many farm holdings.

The building must have been used solely for an agricultural purpose as part of an established agricultural unit on or before 3 July 2012. If brought into agricultural use after that date, it must have been used for agriculture as part of an established agricultural unit.

Prior approval is required for Class R applications. The authority assesses transport impacts and, where relevant, noise and contamination.

Class R vs Full Planning

Class R is a lighter-touch right than Class Q. The assessment criteria are narrower, and the prior approval process is generally less contentious. It is well suited to farmers looking to let surplus buildings for business uses without committing to a full planning application.

It does not, by itself, authorise the erection of new buildings or significant structural alterations. If the building needs substantial work before it is fit for the proposed commercial use, full planning permission may be required alongside or instead of Class R.

Frequently Asked Questions

Can I convert any farm building under Class Q?

No. The building must be structurally suitable for conversion without works that amount to a rebuild. It must have qualifying agricultural use history. Listed buildings, scheduled monuments, SSSIs, and buildings on Article 2(3) land are excluded. If a new agricultural building was erected on the same unit under Part 6 within the last 10 years, Class Q is not available.

Do I need planning permission to extend a farm building?

It depends on the size of your agricultural unit and the scale of the proposed works. On units of 5 hectares or more, Class A of Part 6 may allow new builds and extensions up to 1,500 sq.m (non-livestock) without a full application, subject to prior approval. On units under 5 hectares, Class B applies and the permitted operations are more limited — new buildings are not permitted under Class B at all.

What changed under the May 2024 amendments?

The changes that came into force on 21 May 2024 were substantial. Under Class Q, the dwelling cap increased from 5 to 10 and the total floor space cap increased to 1,000 sq.m. Former agricultural buildings became eligible. Under Class R, the floor area cap doubled to 1,000 sq.m. Under Class A Part 6, the size cap for non-livestock buildings increased to 1,500 sq.m.

What is the difference between prior approval and full planning permission?

Prior approval is a streamlined process that allows the local authority to assess specific defined impacts — typically siting, design, transport, noise, and contamination — without a full assessment of planning merits. The local authority cannot refuse prior approval on grounds outside those defined criteria. Full planning permission involves a broader assessment of all material planning considerations.

Can I use Class Q and Class R on the same building?

No. A building cannot be converted under both Class Q and Class R. Once a building has changed use under one right, it is no longer an agricultural building for the purposes of the other.

How many homes can I build under Class Q?

Up to 10 dwellings on a single agricultural unit, subject to a total floor space cap of 1,000 sq.m across all dwellings. No individual dwelling can exceed 150 sq.m. To achieve the maximum of 10 homes within the floor space cap, each dwelling would need to average 100 sq.m.

Get the Most From Your Permitted Development Rights

Permitted development rights on farms are more powerful than they have ever been — but only if the application is prepared correctly. The 2024 amendments expanded the rights, but the conditions are still specific and errors at the submission stage can still result in refusal or loss of the right.

If you want to understand what your farm can do under Class Q, Class R, or agricultural PDR, speak to Foxes Rural. We handle these applications daily and know where the pressure points are.