Planning Permission for Agricultural Buildings: A Complete Guide

Do You Need Planning Permission for an Agricultural Building?

One of the most common questions we receive from farmers and landowners across Hertfordshire, Bedfordshire, and Buckinghamshire is whether they need planning permission for a new agricultural building. The short answer is: it depends. Agricultural buildings can sometimes be erected under permitted development rights without a full planning application, but there are strict criteria that must be met. Getting this wrong can lead to enforcement action, delays, and significant additional costs.

Permitted Development Rights for Agriculture

Under Part 6 of the Town and Country Planning (General Permitted Development) Order 2015 (as amended), certain agricultural buildings and operations can be carried out without a full planning application, provided specific conditions are met. These rights apply differently depending on the size of the agricultural holding:

Holdings of 5 Hectares or More

• You may erect, extend, or alter a building for agricultural purposes.
• The building must be reasonably necessary for agriculture on the holding.
• The ground area of the building must not exceed 1,000 square metres.
• The height must not exceed 12 metres, or 3 metres if within 3 kilometres of an aerodrome.
• No part of the building may be within 25 metres of a classified road.
• The building must not be used for livestock housing within 400 metres of a protected building (such as a dwelling).

Holdings Between 0.4 and 5 Hectares

• More restrictive conditions apply.
• The building must not exceed 465 square metres in ground area.
• The height must not exceed 12 metres, or 3 metres near aerodromes.
• The same setback rules apply regarding roads and protected buildings.

Exclusions

Permitted development rights do not apply in certain locations, including National Parks, Areas of Outstanding Natural Beauty, the Broads, Conservation Areas, World Heritage Sites, and Sites of Special Scientific Interest. If your land falls within any of these designations, you will need to apply for full planning permission. Parts of Hertfordshire and Buckinghamshire include AONB land, so it is essential to check your site's designations before proceeding.

The Prior Notification Process

Even where permitted development rights apply, most agricultural buildings require a Prior Notification application to the local planning authority before work can begin. This is not a full planning application, but it gives the council the opportunity to assess certain aspects of the proposal.

The local authority will consider:

• The siting and design of the building
• Its external appearance
• Impact on transport and highways
• Noise, odour, and other environmental impacts
• Contamination risks and flooding

The council has 28 days to respond to a Prior Notification application. If they do not respond within this period, you may proceed with the development. If they request changes or refuse, you may need to amend the proposal or submit a full planning application.

When You Need Full Planning Permission

A full planning application is required if:

• The proposed building exceeds the size or height limits for permitted development.
• The holding is less than 0.4 hectares.
• The site is within a designated area where permitted development rights are restricted.
• The building is not genuinely required for agricultural purposes.
• The Prior Notification application is refused and you cannot resolve the council's concerns.

Full planning applications typically take 8 to 13 weeks to determine and require more detailed supporting information, including a Design and Access Statement, site plans, and potentially ecological or flood risk assessments.

Building Regulations for Agricultural Buildings

Planning permission and Building Regulations are separate requirements. Even if your agricultural building is permitted development, it may still need to comply with Building Regulations, particularly if it contains:

• A fixed internal floor area exceeding a certain threshold
• Electrical installations
• Structural steelwork that requires certification

Many simple agricultural stores and barns are exempt from Building Regulations, but it is always worth confirming with your local authority or a building control body.

How Bly Contracting Can Help

At Bly Contracting, we have extensive experience designing and building agricultural structures across Hertfordshire, Bedfordshire, and Buckinghamshire. We understand the planning process inside out and work closely with planning consultants to ensure your project proceeds smoothly. From initial feasibility advice through to agricultural building construction and handover, we manage every stage of the process.

If you are considering a new farm building and are unsure about the planning requirements, contact us for a free, no-obligation discussion. We will help you understand your options and the most efficient route to getting your building approved and constructed.