How does Class Q Permitted Development work?

The procedure has two stages. The first stage is to notify the Council that a change of use is proposed under Class Q (a). The second stage, only possible if the principle has been agreed, is to seek agreement to the actual proposed design and external appearance of the conversion under Class Q (b).

How long does the Class Q approval process take?

The Council only has 56 days to make their decision for Class Q(a). After that it benefits from 'deemed consent' for the conversion and any necessary building works provided they are within the scope of class Q.

Can permission be given to convert separate barns?

Yes, but no more than a total of 10 new Class Q dwellings are allowed on the farm. Open sided barns, such as many Dutch barns, can qualify for converting under the new rules.

Where do Class Q planning rules not apply?

This prior approval procedure only applies in England and does not apply to areas of Outstanding Natural Beauty (AONB), National Parks and Conservation Areas, listed buildings, scheduled monuments, Sites of Special Scientific Interest (SSSI), safety hazard areas or military explosives storage areas. The new rules do apply to barns in the Green Belt.

Will the converted barn still have to look like an agricultural barn?

The Council can assess the design and external appearance of the existing building. Windows and doors can be added as part of the conversion design.

How detailed do the architectural plans have to be?

There don't have to be any architectural plans at all for stage one, but they are essential for stage 2. Those plans would have to be sufficiently accurate and to scale and show all elevations proposed and existing.

Could it be a fairly new barn?

If a building has been constructed and used in farming before 20th March 2013, then an application for a conversion can be made. If the building was constructed after that date, you'd need to wait 10 years before making the application.

What does 'barn' really mean? How about redundant grain silos?

It has to be an agricultural building as opposed to a structure used in the farming industry, so silos would most probably get a 'No'.

How easy would it be to get 'ordinary' planning permission for an extension on a barn?

It's possible but not always easy. It would depend on what is proposed; as a rule of thumb the more modest the proposal the better the chance, and this will vary from council to council.

If successful, would it affect normal agricultural permitted development?

Exercising Class Q in respect of any building will suspend normal agricultural permitted development rights for a period of ten years from completion. You may wish to ensure you have adequate replacement facilities in place prior to submission.

Could the barn be falling down?

It may currently look a mess, but it's the building's basic underlying structure that matters. Its main framework must be sufficiently robust for conversion to a habitable dwelling without the construction of new structural elements. The building does not even have to have full existing foundations or an existing concrete slab base so long as the foundations of the framework itself are in good shape.

Is a barn conversion still possible at a remote or 'unsustainable' location?

The Government has clarified that 'undesirable' and 'impractical' has more to do with being difficult to access by road or close to an area where its quality of amenity would be poor due to adverse environmental effects (noise, smells etc). A remote or isolated location is not now automatically ruled out.

What about a site with contamination or flooding?

It is good practice to submit details at stage one to demonstrate there are no concerns and prevent the Council refusing consent due to 'lack of information'. If the barn is in flood zones 2 or 3 you will need to submit a site specific flood risk assessment upfront.

How small could the barn be to convert?

There isn't a lower limit however it must be at least a 1 bed unit otherwise it would be 'impractical or undesirable'. It must also have some kind of curtilage and outlook, space for bins, etc.

If successful would it have an agricultural occupancy condition?

Although it is quite rare, some councils impose agricultural occupancy conditions where they consider it necessary due to such things as the close proximity of other farm buildings which are still used for animals. This may also be done via a Section 106.

What about rural barns that are not agricultural or do not qualify?

It is still possible to get 'ordinary' planning permission to convert other barns in the countryside into homes. The 'rule of thumb' is that the barn concerned must be structurally sound and is either of some architectural, historic or landscape merit.

What about garden and parking space?

Basically this must be no more than the curtilage of the building, which may be quite generous. The rules do make some provision for the inclusion of extra land not actually in the building's curtilage, so long as the land is no larger than the area occupied by the building and where that land is immediately beside or around it.

Can the barns be used for other uses?

Yes, there are other rules (Class R) which allow agricultural buildings under 500 sq. m. to change to a flexible commercial use, including retail, financial and professional services, café, business, storage and distribution, hotels, assembly and leisure uses, as well as schools and nurseries.

Why We Don’t Use AI In Our Planning Documents

At AFA, we know that the quality of a well-crafted and researched planning document will always capture the nuance and history of your project better than any AI-generated piece of content. We value the expertise and years of experience held within our team, and we’re proud to apply all of those skills to your planning documentation.

We Are a Quality-First Organisation – That Means No AI-Generated Content

While AI has transformed the way planning information can be accessed and analysed, it cannot replace the expertise, judgement, up-to-date knowledge, and strategic thinking of an experienced senior planning consultant.

At AFA Planning Consultants, quality always comes before speed. That is why we do not use generative AI to write our planning objections, planning statements, appeals, or supporting planning documents. Every report we produce is researched and prepared by our experienced senior planning consultants who understand the complexities of the UK planning system and the importance of presenting accurate, well-reasoned, and site-specific planning advice.

The Gaps in AI Reasoning

Planning is not just about assembling information, as every case will have its own unique planning history, local development plan policies, material considerations, planning constraints, and surrounding context. A successful planning submission requires careful professional judgement and a complete understanding of how local planning authorities interpret and apply planning policy in practice. These are skills that come from years of professional experience, not automated text generation.

As you may already be aware, most AI models are LLM’s (Large Language Models), meaning that they notice patterns in text and digital information to regurgitate to the user. It is important to know that AI doesn’t think, it just presents you with a collection of text from different corners of the internet that it has reasoned to be the most likely to be relevant.

Because of that, it can produce inaccurate information, rely on outdated guidance, misinterpret planning policy, or fail to appreciate the nuances between different local authorities and jurisdictions.

Due to the fact that it values all sources as equal (a blog post from an unverified source could be held on the same level as information from the council), the chances of it being incorrect have been placed somewhere between 20%-40% in independent studies. In planning, even a small factual error or an incorrect interpretation of policy would weaken a case or, in the worst-case scenario, be grounds for dismissal. Generic content from AI also fails to demonstrate the detailed planning balance that decision-makers expect to see when assessing complex proposals, again weakening your case.

We recognise that our service is not the cheapest option, and we do not aim to compete with businesses offering automated or AI-generated reports at the lowest possible price. Our clients invest in professional expertise because they understand that the quality of a planning submission can have a significant impact on the outcome. Often you have one chance to get it right.

You Can’t Replace Trained Professionals

Our planning officers and inspectors will assess the quality of planning arguments, the relevance of supporting evidence, and the professional reasoning behind every submission, and each of our reports are prepared by experienced consultants who demonstrate a depth of critical analysis and strategic thinking that cannot be replicated through automated content alone. Every document we produce reflects our professional reputation, and we take responsibility for every recommendation, opinion, and conclusion contained within it.

Unlike AI-generated planning advice, every case at AFA Planning Consultants is personally managed by a senior planning consultant with extensive experience working at a senior level within local authority planning departments. Their insider knowledge of planning policy, decision-making processes, and local authority expectations enables us to prepare bespoke planning strategies and reports that are tailored to maximise the prospects of a successful outcome.

Why AI-Generated Content Fails In Planning

Lacks professional judgement

AI can summarise information, but it cannot apply the experience or the critical thinking needed to assess complex development proposals.

Cannot undertake a true site appraisal

Every site has unique physical constraints, planning history, and local context that require professional interpretation.

May rely on incomplete or outdated information

Planning policy changes regularly at both national and local levels, and AI-generated content often overlooks recent policy updates, emerging guidance, or authority-specific requirements.

Can generate inaccurate references

AI systems are capable of producing incorrect citations or referencing guidance that is not applicable to the specific planning circumstances.

Lacks strategic planning expertise

Successful planning, whether for applications or appeals of objections, is more than a collection of facts and requires a carefully developed strategy.

Produces generic rather than bespoke reports

AI often generates broad, template-style content that fails to reflect the unique characteristics of a site, development proposal, or local planning authority's expectations.

Cannot negotiate or exercise professional judgement

Experienced planning consultants know when to adapt a strategy and respond to planning officer feedback that automated systems simply cannot recognise.

No professional accountability

AI does not take responsibility for the advice it provides. At AFA Planning Consultants, every report is prepared and signed off by experienced senior planning professionals who stand behind their work and the advice they give.