What is an agricultural unit?

What is an agricultural unit? Does my other field qualify? What if I have a road, river or houses separating my land? What happens if I am renting a field – does it qualify?

Once you have confirmed that the use of your land is agricultural, the next question for Part 6 is often how large the agricultural unit actually is.

Within Class Q, Class R & Class S of Part 3 an agricultural unit is described as ‘agricultural land occupied as a unit for the purposes of agriculture‘.

Within Class A, Class B and Class C of Part 6 an agricultural unit is described as ‘agricultural land which is occupied as a unit for the purposes of agriculture, including— (a) any dwelling or other building on that land occupied for the purpose of farming the land by the person who occupies the unit, or (b) any dwelling on that land occupied by a farmworker;’

With the GPDO it is always important to check the definition of words and phrases as this might affect your usage. For example in Part 6 you can include any dwellings occupied by farmworkers. That definition does not itself grant permission for a new home; see our separate guide to rural workers’ dwellings and agricultural occupancy ties for the planning tests applying to a new dwelling in the countryside.

Multiple parcels of land in the agricultural unit?

The good news however is that an agricultural unit can be formed of various parcels of land farmed by you and does not have to relate only to the field or parcel of land where you intend to exercise your permitted development rights.

What if the land is owned by someone else or is on another title. That should not matter as long as it is all farmed by you and is part of the same agricultural unit. Ownership is not the statutory test. What matters is whether the land is genuinely occupied and managed as one agricultural unit. Evidence may include ownership documents, a tenancy or licence, farm records, accounts, maps and the way the holding is actually operated. If the field is owned and farmed by your mate from the local hostelry then no – it will not be part of the same agricultural unit. Sorry!

The various parcels of land can be divided by rivers, roads or even houses to still form part of the same unit.  It might be pushing it a bit if they are in different town, but it could be the next village in a rural setting. The important factor is that they must be one unit.

It is worth pointing out a couple of important elements. With regards to converting barns your are limited the amount of conversions per agricultural unit, therefore this needs to be carefully considered. Also with regards to Class A and Class B of part 6 different rights apply to whether your agricultural unit is over or under 5 hectares. So you might wish to add these up carefully. The Magic website from Defra has a mapping tool to assist you in this task. If your agricultural unit is less than 0.4ha then unfortunately Part 6 of the GPDO will not apply.

Finally in Class A you do need to ensure that any development is on land greater than 1ha as long as the overall unit is 5ha or more.

For an agricultural unit of 5 hectares or more, start with Class A of Part 6. The separate change-of-use rights in Class Q, Class R and Class S have their own eligibility tests and are not switched on merely because the unit exceeds 5 hectares.

For an agricultural unit of at least 0.4 hectares but less than 5 hectares, start with Class B of Part 6. Again, Class Q, R and S must be tested against their own wording rather than the 0.4 or 5 hectare Part 6 thresholds.

Other Agricultural Sections

Agricultural Unit Page Updated: 22nd August 2026