5 myths about planning and granny annexes

The worldwide web creates all sorts of tales made to confuse and steer searchers, and planning for granny annexes is no exception. NAPC have created the 5 most misunderstood things about planning permission and annexes.


  1. If I build a Granny Annexe, I do not require planning permission


Some companies tend to create clickbait with ‘Granny Annexes No Planning Required’, however this is just simply not the case.

This is due to the fact that an annexe is considered as an ancillary outbuilding, so you will always require relevant planning permission from your LPA due to it containing sleeping accommodation.

Granny Annexes and some Garden Rooms are not permitted development, and NAPC recommend seeking advice if you decide you’d like to build one.

NAPC would be more than happy to assist with any enquiries.


  1. An Annexe is defined as a separate dwelling in the garden


LPA’S will have their own policy in place with regards to what they determine to be an annexe. Plus, some simply do not have a policy at all.

Within ALL cases an annexe must be considered ancillary to your main dwelling. So for example,

  • Used by a family member
  • Can never be sold separately
  • Can never be rented out
  • No separate address
  • Shared services to the main house
  • No separate access
  • No separate garden

Planning is an extremely specialist area and it’s always best to seek assistance from planning consultants.

NAPC have 15years within this field, working with various LPA’s to secure approvals.


  1. You Can Put An Annexe In A Paddock or Field Near Where You Live


Baseline rule – annexes must always be sited within the curtilage of your property.

An application will be slightly more difficult to approve when trying to build within a field or paddock. In order for this to be approved,  it may mean submission to extend your curtilage.

Don’t panic…NAPC will be able to advise on what is curtilage and what is not.


  1. I am able to design an annexe to my exact specification


Of course many of the garden annexe providers we work with will try their upmost to create your ideal annexe, however compromises may have to be made in order for the LPA to approve.

Things that the LPA will question:

  • How many bedrooms there are
  • Level of facilities
  • Who is going to live in the annexe now and then in the future
  • Whether there is a need to build an annexe as opposed to extending the existing dwelling
  • The overall size

The Local Planning Authority are likely to question whether 2 bedrooms for instance, is a necessity.


  1. Bungalow/Cottages in the Garden – Annexe in Garden = the  same thing


From several providers, their annexes look like bungalows, but there are slight differences.

For many the type of foundations uses are different plus the exterior cladding which will remain in good appearance for many years to come.

Sometimes annexes can be classed and built as mobile homes and are therefore zero rated for vat purposes.

If you want success when coming to your planning application for an annexe, NAPC are only a phone all or email away!





Get an answer quicker with a Feasibility Study

A one-off Feasibility Study (from £99) will equip you with crucial planning insight about the area you’re planning to site your Annexe or Garden Room. So if you pursue your application, you have the best chance of success. 

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Book a call with one of our planning experts or call/email us directly.

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01285 283200



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Annexes are now a popular addition to many family homes to provide additional accommodation.

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