Can I Have A Brick Granny Annexe?


One of the most frequently asked questions we get is about the possibility of having a brick granny annexe.

For some people the idea of living in an annexe is a “proper little home” at the bottom of the garden and that means a brick built granny annexe is what they have in mind.

The fact is of course it can be done. 

Annexes are typically constructed on-site as either a timber-frame insulated building (like a new home) or with SIPS (structurally insulated panels) (a modern day construction method that is designed for strength and speed of construction.)

The main differences other than that are:-

So why is it that you don’t see more brick granny annexes?
Read on to find out the top 3 problems associated with building a granny annexe in brick and one possible solution that may suit you.

1. Planning permission is very unlikely to be granted for a brick granny annexe

Granny annexes are classed as ancillary buildings to the main house, not a separate dwelling.

There must be “a link” to the main house and can only ever be sold as part of the main property.

Your Local Planning Authority will control this use via the conditions they will apply to any permissions they grant for the annexe to be built.

Your Local Planning Authority is highly unlikely to grant permission for a separate dwelling in your back garden.

And contrary to popular belief (thanks Google) ALL granny annexes require permission of some kind to be built whether they are classed as mobile homes or not.

You will need either a Certificate of Lawfulness or Householder’s Planning Permission to build an annexe in your back garden.

Both are only available via your Local Planning Authority and this is a service we offer on your behalf as part of our turn-key services.

Without the relevant permission you simply cannot build a granny annexe.

2. It will cost you at least 20% more than a regular granny annexe

If you are thinking of building a brick built granny annexe it will not be classed as a mobile home for VAT purposes and therefore become 20% more expensive to build because your builder will have to charge VAT @ 20%.

Your Local Planning Authority will have a policy about what they refer to as backland development (which is a very specialised area best dealt with by Planning experts.)

However it covers 3 main areas that would be affected by a brick built granny annexe in your back garden.


Access typically refers to existing and future residents of your area, access for emergency services, cyclists, cars and pedestrians and lead to more cars being parked on the street etc.


Any annexe (whether it is a brick granny annexe or not)will take into consideration your neighbouring properties to all aspects of your property and garden. Considerations for them will include impacting their privacy, daylight, sunlight, outlook and light pollution. Neighbour objections are common with granny annexes as it always highlights people’s natural concerns about something that might affect their lives.


If you are in an area of outstanding natural beauty, green belt or a conservation area planning permission is likely to be even more difficult for a brick granny annexe. Location will also be a significant factor plus any precedents that have already been set within your area.

Always consult an annexe planning expert before you dive in and get carried away with your brick granny annexe plans.
Annexes are not self-building your own home in your back garden. An annexe is an annexe.

3. Why not build an extension? Your LPA might ask

In the UK today there is high demand for homes.

That’s why the Government  set targets of 1 million new homes by 2020 and no doubt you have thousands of new homes currently being built near you right now?

I know we do here in Shifnal in Shropshire (there are hundreds in what used to be fields all round us!)

So surely one brick granny annexe in the back garden isn’t going to hurt anyone? Right?

Unfortunately your Local Planning Authority may well have no objection to the Government demanding build schedules for the most part (some do get refused by the way) but might well object to your plans to build a brick annexe in your back garden and issue a refusal.

That’s the nature of planning in the UK and why it should be handled in the right way from the start.

If you are thinking of building a brick granny annexe give careful consideration to building an extension instead and using up your permitted development rights to the full.

“But I want to be separate to the main house I hear you cry!”

One possible compromise that might suit if you have the budget

If you have come this far and lost heart with building a brick granny annexe we may just have a silver lining for you.

Providing your Local Planning Authority is perfectly OK with the concept of building an annexe in your back garden and it ticks all the boxes for them:-

They might consider allowing your external cladding to be brick slips. This will give the appearance of brick on the outside but satisfy your Local Planning Authority that it is indeed a granny annexe.

The downside to using brick slips is the added cost.

You will typically need to add £8,000 to £10,000 to your budget for this type of exterior cladding finish.

In Summary

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