
Can I extend a barn conversion?
In general planners have a dislike for barn conversion extensions. Most councils have policies that effectively exclude them. But there are some exceptions, as long as you follow some simple planning and design considerations that respect the structure’s character.
What is a barn conversion extension?
This might be a simple lean-to extension to add more space. Or possibly re-building the U shape as in this case study.

Generally, as barns are in open-countryside, new-build is not an option. However, re-building former barns can sometimes be granted with significant justification to the planning authority. For example, we obtained planning permission for this Coolington barn to re-build surrounding ‘hovels’ and turn them into living space and classic car workshops.
The barn conversion extension case study shown here is unusual. It took a lot of determination and perseverance with the local authority to justify the importance of re-building the former hovels. This entailed much historical research and drawings to demonstrate how parked cars would look worse in this prominent position on the hillside, without lovely workshops to hide them in!
NB. Hovels are simple open sided barns used for housing livestock or as general farm storage.
What about extending an existing barn conversion?
In the case of extending an existing barn conversion that is already a home – it is still very tricky! Permitted development rights are generally removed after permission for a barn conversion is received. Therefore, usual homeowner extension policies do not apply.
Barn Conversion Extension Case Study 2
We recently obtained planning permission for an extension to a barn conversion. It took careful navigation and liaison with the planners and conservation officer. Eventually an extension in-line with the original barn was granted. Effectively making the barn longer. This may not be your preferred layout. We reorganised internal rooms to make it work. This gave better access to the garden and improved light coming into the kitchen. Result – very happy clients!
We are very pleased with the outcome [of our barn extension], the development has totally changed the house, garden and how we live for the better. Mr and Mrs M.
There’s further information about planning permission for barn conversions here.
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You can also download a copy of our free Barn Conversion Guide here, created with our years of knowledge and specialist expertise, so you don’t make costly mistakes during your project.
Photographs above courtesy of IQ glass.
FAQs
Do you need planning permission to extend a barn conversion or can I use permitted development rights?
Permitted development rights are generally removed after permission for a barn conversion is received. Therefore, usual homeowner extension policies do not apply.
What materials are generally preferred when adding a barn extension?
The same or similar materials to the original barn would usually be appropriate, but obviously there are exceptions!
What types of extensions work best for barn conversions?
Simple is best. Barns are not fussy buildings. Pitched roofs work better than flat roofs.
What’s the best way to connect a modern extension to a barn conversion?
Barn-like forms would be preferred over anything too domestic looking.
Can you extend a listed barn conversion?
This would be trickier, but not impossible. Usually a glazed connection would be required to separate old and new.