Annex & Outbuildings

Annex (or Granny Annexes as they are often called) are often in detached outbuildings but can also be added as extensions to existing properties.

While an annex or outbuilding can sometimes be undertaken through permitted development, in many cases it will require planning permission. A permitted development extension or outbuilding will be limited by the scale, materials and use.

For an annex property, the use becomes critical and whether it is classed as an “incidental” or “ancillary” use (just another room in the house or self-contained).

The definitions and arguments surrounding “incidental” and “ancillary” are complex and obtaining professional advice before undertaking any work are vital.

At Plande, we are able to assist with your annex or outbuilding projects and can guide you through the process, advising of the options and limitations as well as managing the application, or Lawful Development Certificate process.

Granny Annex Outbuildings Garden Planning

The following case studies provide a small sample of the different types of annex and outbuildings we have been involved with.

Granny Annex Planning Permission

Certificate of Lawful Existing Use as a self-contained dwelling rather than Annex, Stretford (Manchester)

Our clients had obtained planning approval for a change of use of a garage into a Granny Annex.

During construction works the existing garage was demolished and the new annex building was constructed in a different location to the approved drawings, meaning in effect all works were unlawful and no planning approval existed. The building also didn’t comply with several planning conditions including the limitation of the use a Granny Annex. We successfully argued, not only, for the retention of the unlawful building but to allow for the building to be allowed to continue to be a self-contained dwelling rather than annex accommodation.

NB. A robust justification with appropriate evidence is required to prove “on the balance of probabilities”.

Local Planning Authority: Trafford Council

see also: Self Contained Dwelling; Certificate of Lawful Development; Backland Development

Change of Use Granny Annex Planning Permission

Certificate of Lawfulness for detached annex structure outside of the settlement boundary, Flintshire

Our clients required additional annex living accommodation to house elderly parents. Having previously and substantially extended their property it was unlikely that Flintshire County Council would grant approval for additional extensions.

We sought clarification from the Council that a detached annex structure, providing the necessary accommodation, would be lawful without seeking planning approval. Following protracted negotiations and discussions with the Council, which included seeking additional assistance from a specialist Barrister, we obtained confirmation that a detached structure would be acceptable, the siting was within the residential curtilage, and the proposed use of that structure would not constitute a material change of use of the land and would be incidental to the main dwelling house.

Local Planning Authority: Flintshire County Council

see also: Certificate of Lawful Development; Outside of settlement boundary

Planning Appeal Annex

Resubmission and Approval of previously refused application relating to Annex. Cheshire

The initial application for a Change of use/ conversion from a granny annex to self-contained residential dwelling house was refused planning permission on several grounds. The client sought to convert the existing building into a new house that could be used independently and sold as a family home.

Following a review of the existing application, we concluded that a negotiation and resubmission at the local level stood a greater chance of success. It was noted that an appeal could still have been submitted should this not have been the case.

We created a robust justification for the proposals and pre-application resolved the previous refusal reasons which included highways and parking issues. The application was subsequently recommended for approval subject to a Section 106 agreement for a financial contribution to open space provision within the area.

We successfully argued for a removal of this requirement and the application was subsequently approved with no financial contribution requirement, saving our client several thousand pounds and allowing the property to be sold, creating a substantial profit.

Local Planning Authority: Trafford Council

see also: Self Contained Dwelling; Certificate of Lawful Development; Planning Appeals

Variation of Condition Granny Annex

Variation of Condition restricting access to Annex accommodation


Local Planning Authority: Bassetlaw District Council

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This page provides an introduction only and is not a definitive statement of the law and should therefore not be relied upon.
The information above relates to England only. Policies across the rest of the UK may differ.
Contact your Local Planning Authority for advice and confirmation before any works are carried out.