For most these terms ‘Ancillary and ‘Incidental’ are unfamiliar and not used frequently at all.
However, when it comes to Annexe building, there is a crucial difference between the two in terms
We hope that NAPC can provide some clarification on the subject.
From many reports and research, garden buildings and annexes have never been so popular as there
are today, but many householders struggle to understand the difference between incidental
development and ancillary.
Incidental Development – something that is required by Class E Permitted Development Rights
Ancillary – something that requires planning permission
Unfortunately many can be misadvised and therefore increase the amount of enforcement cases.
Ancillary in short is everything you can do in a normal dwelling from sleeping, cooking, taking a
shower , watching the tele etc.
If you are building a space such as a granny annexe that contains facilities to accommodate this, such
as a bedroom, kitchen area or bathroom, this then means the annexe does not benefit from Class E
In this scenario, planning permission would be required, but if you’re unsure please do not hesitate
to contact NAPC for further guidance.
So lets look at incidental development
Within the General Permitted Development Order, it states the homeowner is allowed to construct
an outbuilding within their curtilage with no need for planning permission. There are also other
factors to consider such as height and foot print.
Incidental can be described as a by-product of primary function. So therefore buildings for a purpose
incidental to the enjoyment of the primary house.
Types of buildings this could include:
- Home Office
- Beauty/Art Studio
- Home Gym
- Pool House
- Cinema Room
- Games/Hobby Room
If you add a toilet into a home office or shower into a home gym, it may still be considered
At NAPC we are specialists when it comes to obtaining planning permission whether that be for your
Granny Annexe or Garden Rooms, get in contact to see how we may best assist you.