Black Class Q dutch barn conversion

Class Q Permitted Development

Convert your agricultural building into a beautiful and sustainable home.

As a general rule, it is not permitted to build new homes in the open countryside. However, if you have underutilised or redundant agricultural buildings, it’s possible to use your Permitted Development Rights and convert them to residential use.

Commonly known as Class Q, the legislation allows for the conversion of up to 865 sqm of the existing agricultural building to provide a mix of 5 dwellings.

Class Q Converted barn into housing in farm location

Development opportunities

Under the guidelines, it is possible to provide up to 5 new dwellings on a single agricultural unit, which allows for the following in one or more agricultural buildings;

  • Up to 3 larger dwellinghouses with a maximum cumulative total residential floor space of 465sqm, or
  • Up to 5 smaller dwellinghouses each no larger than 100sqm of residential floor space, or
  • A mix of larger and smaller dwellinghouses within a total of no more than 5 dwellinghouses, of which no more than 3 may be larger dwellinghouses with a maximum cumulative total of 465sqm residential floor space


A simple barn conversion of a small brick and corrugated iron barn into an attractive brick and slate dwelling utilising Class Q permitted development.

before photo of brick barn with corrugated roofBefore

after photo of finished building with skylight windows


exterior rear view of converted barn with recycled materials and exposed beams

Development Restrictions

Some restrictions apply which would prevent using this route, such as if the property is in a very remote location away from a road, Listed or within an Area of Outstanding Natural Beauty or Conservation Area.

Any approval will allow for the change of use of the building and some alterations such as replacing roofing and forming new window and door openings. It does not allow for any works that would increase the size of the building such as extensions or porches. A planning application would be required for these additional works.

The extent of works permissible under the Class Q route is somewhat restrictive and whilst it sets a precedent for providing a new house, the approval may not maximise the potential of the site or your finances.

rear of the barn before conversionBefore

side of barn with log pile wallAfter

A Class Q Conversion transforms a dilapidated barn into a quirky holiday let near Blandford.

barn conversion with beautiful countryside views from end of garden

Why choose WDA?

We have a strong track record and extensive expertise in Class Q projects and excel in navigating the challenges associated with agricultural building conversions. Our architects skillfully blend modern elements with existing structures, preserving authenticity and character while meeting regulatory requirements.

Through close collaboration with our clients, we prioritise translating your visions into distinctive, practical spaces, alongside incorporating sustainability and energy efficiency when possible. This commitment ensures that our projects not only meet expectations but also stand the test of time.

stunning distant view of modern home at dusk

The fallback position

The fallback position provides a route to improve an existing class Q planning consent.

Some buildings are also simply unattractive or too large to make into a beautiful new home through the Class Q route.

Local authorities now accept that following the grant of approval under Class Q, a planning application can be submitted and considered for approval for a completely new residential development. This is in lieu of converting the existing building, referencing the Class Q as a fallback position to make the case the principle has already been established on the site.


concept for a new farm house with red bricks and attractive patio area

There are several distinct advantages to doing this, some of which are;

  • You are not constrained by the form and shape of the existing building which will allow you to make better use of the site and provide a more attractive building and surroundings.


  • A planning application relying on the fallback position can include changes to external works and ground levels, something not permissible under Class Q.  Landscaping proposals are essential to ground a building in its setting.


  • There is scope to reposition a new building on the site if it will provide clear enhancement. Whilst a planning officer might not allow placing the new building a distance away from the existing, we have successfully gained approvals to reposition a building on a site.
visual of rear view of house with beautiful countryside views
  • Each application is judged on its own merits but it’s also possible to make the new building larger than the Class Q approval.


  • A planning approval means you will only need to make a start on site within 3 years, whereas a Class Q approval must be complete within 3 years. This gives you flexibility in terms of time to build out the approval.


  • Whilst VAT on build costs is reduced to 5% on the conversion of agricultural buildings to residential, there is no VAT if you demolish the existing build a new home.

There is no guarantee a Local Authority will grant approval for a Class Q approval, let alone a subsequent planning approval for a new dwelling.

We are receiving an increasing number of successful approvals which have recognised the legitimate material consideration of the fallback position.

Agricultural Portfolio

Take a look at our range of Class Q projects within our Agricultural Portfolio. Simply click the filters buttons to view our sub sectors.

Agricultural Projects
red tile roof to barn behind flower meadow
rear elevation of house and garden patio at dusk

Continue your journey…

Read more about the design stages and our architectural services on our comprehensive Services page or head back to our main Agricultural Sector page to view other types of residential projects.