Introduction
Residential annexes are a common form of development. Annexes can allow relatives to live with their family with some independence. The Council often considers such proposals acceptable. But this requires caution, to ensure that this does not result in proposals which:
- is the same as creating a new dwelling,
- may be in an inappropriate location, and
- represent unsustainable development.
General Policy Considerations
a) Have a functional link with and be ancillary to the principal dwelling. This means that annexe occupants would rely on facilities in the main house. Or occupants of the annexe and main dwelling may need to support each other.
b) Be in the same ownership as the principal dwelling and remain as such.
c) Be within the curtilage of the principal dwelling and share its vehicular access.
d) Be well related to the principal dwelling and could be:
- an extension to the principal dwelling;
- a detached new building; or
- the conversion of an existing building.
In the countryside, annexes should be a physical extension to the main dwelling if possible. If it is not possible to extend the dwelling, then clear justification must be provided. This must show why the annexe needs to be within a separate building. As a guide, the annexe:
- should not exceed 50% of the footprint of the existing dwelling and
- should show how it can be incorporated into the main dwelling when there is no longer a need for the annexe
e) Have no set boundary or sub division of garden areas. The annexe and principal dwelling should share curtilage.
f) Be of a scale subservient to the principal dwelling. It should comply with the Council’s normal design standards.
Cornwall Council recognise no two proposals will be the same. Applicants/agents should submit a supporting statement with their application. This should explain how the proposed use of the annexe will be ancillary to the host dwelling. Information such as:
- who will occupy the annexe,
- their relationship with the occupants of the host dwelling,
- shared use of rooms in the host dwelling,
- comments on how the proposal complies with criteria a to f above.
Annexe proposals that include more than one bedroom will normally be refused. This is unless there is a specific and compelling reason for a second bedroom. For example:
- the occupants of the annexe require live-in care which the occupants of the host dwelling are unable to provide. An explanation of why this would not be possible would be required; or
- where a parent or parents occupying the annexe require additional accommodation for children.
The size and floor plan of the annexe should not allow for the later subdivision of rooms. Consideration could be given to homeworking space if a need can be demonstrated. Where needed, Planning case officers may request further information. This is so they can gain an understanding of the context and justification for the proposal.
Policy 7 of the Cornwall Local Plan covers permissive subdivision of dwellings. Annexes are not included in this. This is set out in paragraph 2.35 of the explanatory text.
Issues for Validation
The definition of “householder application” in the 2015 Procedure Order is:
(a) an application for planning permission for development for an existing dwellinghouse, or development within the curtilage of such a dwellinghouse for any purpose incidental to the enjoyment of the dwellinghouse; or
(b) an application for any consent, agreement or approval required by or under a planning permission, development order or local development order in relation to such development. But does not include an application for change of use or an application to change the number of dwellings in a building;
This would include all proposals for annexes which are extensions to the dwelling (and which relate to development ancillary to the use/occupation of the existing dwelling). Such applications have a fee of £258*.
Detached annexes and outbuildings used for ‘ancillary’ purposes do not fall within the definition set out in the Procedure Order.
Note:
i) Incidental outbuildings within the curtilage of dwellings (garage, shed, store, home office, hobby room, home gym etc.). Fee £258*, householder application form.
ii) Ancillary outbuildings within the curtilage of dwellings: bedroom, bathroom, living room etc. but not fully self-contained. Fee £258*, full planning application form.
iii) Self-contained outbuildings (bedroom, living room, bathroom, kitchen – facilities of a dwellinghouse) Fee £578*, full planning application form.
*Fees correct as of December 2023 and may be subject to change.
Conditions
The Council may impose a planning condition for an annexe. This is when the creation of an additional dwelling is unacceptable. There will be sound planning reasons in these cases.
Example conditions:
1. The annexe as indicated on Drawing No xxxx shall only be used as ancillary accommodation. The annexe shall only be occupied by members of the family or non-paying guests of the occupiers of the dwelling (outlined in blue) known as xxxxxx. It shall not be used at any time as a separate residential unit of accommodation.
or
2. The building hereby permitted shall not be occupied at any time other than for purposes ancillary to the residential use of the dwelling known as xxxxxx.
Sustainable Energy and Construction Expectations
Policy SEC1 applies to self-contained annexes. The Climate Emergency DPD Policy Guidance (chapter 12) ) sets out special provisions for very small homes. It can be challenging to apply the Policy SEC1 2b energy thresholds in full in these cases.
