Class Q Conversions
Class Q barn conversions under permitted development.
Understanding Class Q Conversion: Turning Agricultural Buildings into Homes
In recent years, Class Q permitted development has become one of the most exciting opportunities in rural England for those looking to create unique homes without going through the full planning permission process. Whether you're a landowner, developer, or someone dreaming of converting a barn into a beautiful countryside dwelling, Class Q can offer a flexible and efficient route to achieving your vision.
At Archico, we regularly guide clients through Class Q conversions, ensuring their proposals meet all requirements while creating practical and inspired residential spaces. Here’s everything you need to know.
What Is Class Q Permitted Development?
Class Q is a planning permission exemption that allows the conversion of certain agricultural buildings—such as barns, stables, or outbuildings—into residential homes. Introduced under the Town and Country Planning (General Permitted Development) Order, Class Q aims to support the reuse of existing rural buildings and boost rural housing supply.
In most cases, you can convert an eligible agricultural structure into up to ten dwellings (depending on floorspace) without submitting a full planning application.
Key Eligibility Criteria
Not every agricultural building automatically qualifies. To meet Class Q requirements, your building must:
1. Be (or formerly part of) an established agricultural unit (EAU)
If the barn is currently part of an EAU, it must have been part of that unit on 24 July 2023. If it became part of an EAU after that date, you must wait 10 years before applying under Class Q.
If the barn was part of an EAU but is no longer, it must have ceased being part of the unit before 24 July 2023. If it ceased after that date, a 10-year waiting period applies. The building must also not have been used for any non-agricultural purpose.
Have not used Class A or Class B of Part 6 (for new agricultural buildings or extensions) in the last 10 years. If the barn was built using these permitted development rights, you generally must wait 10 years before undertaking a Class Q conversion.
2. Be capable of conversion
The structure should be physically robust enough to support a residential conversion. This usually means the existing frame, roof, and walls must remain intact, with works limited to what is considered “conversion” rather than full “rebuild.”
3. Fall outside certain restricted areas
Class Q does not apply to:
Listed buildings
Buildings in Areas of Outstanding Natural Beauty (AONB)
National parks
Conservation areas
Sites of Special Scientific Interest (SSSI)
Safety hazard zones
4. Meet floorspace limits
Under Class Q you can convert agricultural buildings to:
Up to 10 dwellings in total, provided the total floorspace converted does not exceed 1,000 m², and
No individual dwelling exceeds 150 m² in internal floorspace.
Additionally, you may construct a single-storey rear extension of up to 4 m depth, but only if it is built on existing hardstanding. All conversions and extensions must stay within these limits.
What Work Is Allowed Under Class Q?
The permitted development rights allow reasonable building works necessary for conversion, including:
Installing new windows, doors, roofs, or external walls
Strengthening the structure (as long as it’s not effectively a rebuild)
Adding utilities and insulation
Internal reconfiguration
However, extensions are not usually permitted, and the building's footprint must remain the same.
How the Class Q Application Process Works
Although a full planning permission isn’t required, you must submit a Prior Approval application to your local council. This ensures the proposal meets key considerations such as:
Transport and access
Noise impact
Design and external appearance
Flood risk
Contamination
Natural light for habitable rooms
Councils typically respond within 56 days.
At Archico, we prepare the necessary drawings, structural documents, and design rationale to present the strongest possible case for approval.
A Strategic Step to achieve Full Planning for Greater Flexibility
A Class Q prior approval allows the conversion of an agricultural building into a dwelling, but it does not provide the full flexibility of a traditional planning permission. The works are limited to the conversion itself and any minor extensions permitted under Class Q, while larger changes, such as additional extensions, significant design alterations, or other works outside the scope of Class Q, still require a full planning application.
The advantage of securing Class Q first is that it establishes the principle of residential use on the site, which becomes an important material consideration for any subsequent full planning application. Councils cannot reasonably refuse a later application solely on the basis that the site is unsuitable for housing, since Class Q demonstrates that a dwelling is acceptable in principle. This approach has been recognised in case law and planning practice, making Class Q a strategic route to achieve a more flexible or better-designed home than the strict limits of Class Q alone would allow.
Benefits of a Class Q Conversion
1. Faster and simpler than full planning
The Prior Approval process is more streamlined and often less contentious.
2. Unique architectural opportunities
Barns and agricultural structures offer dramatic volumes, exposed frames, and character features rarely found in new-builds.
3. Adds significant value to rural land
A successful Class Q approval can substantially increase the value of agricultural buildings.
4. Sustainable reuse
Reducing the need for new materials supports lower carbon development.
5. A home in the countryside
In the countryside, there are generally two routes to build a home. Paragraph 84 allows new dwellings only if they are of exceptional quality and specification, often at significant cost. Class Q, by contrast, offers a more accessible alternative without the same high expense.
Common Reasons for Class Q Refusal
Although Class Q offers flexibility, councils frequently reject applications for reasons such as:
Poor structural condition
Excessive rebuilding
Inadequate natural light
Unsafe access or highway concerns
The building’s agricultural use not being properly established
Our team performs early feasibility checks to minimise these risks and provide realistic advice from the start.
Thinking About a Class Q Conversion?
A Class Q project can be incredibly rewarding, but the regulations are nuanced and highly interpreted by each council. At Archico, we specialise in guiding clients through the process—from early feasibility studies to drawings, planning submissions, and coordination with structural engineers.
If you’re considering converting an agricultural building into a stunning rural home, get in touch with us for an initial consultation. We’ll assess your building, advise on eligibility, and help you bring your vision to life.