Appeal 3337310

The appeal is allowed and planning permission is granted for alterations to existing garage with conversion and extension of an existing workshop to create a garden room at [site address] in accordance with the terms of the application, [name]/23/03127/FULL, subject to the following conditions:

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plans: Location Plan and [name]. 240523/001RevB.

The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those used in the construction of the exterior of the existing building.

A new version of the National Planning Policy Framework (the Framework) was published on 19 December 2023 and therefore I have referred to that revised document in my determination of this appeal. I am satisfied that the parts of the Framework most relevant to this appeal have not substantively changed from the previous iteration.

The main issue is whether the proposal would be inappropriate development in the Green Belt having regard to the Framework and any relevant development plan policies.

Paragraph 154 of the Framework states that the construction of new buildings is inappropriate in the Green Belt but it sets out a number of exceptions. This includes at 154c) the extension or alteration of a building provided that it does not result in disproportionate additions over and above the size of the original building. Policy SP4 of the Central Bedfordshire Local Plan 2021 (LP) requires that development proposals within the Green Belt be assessed in accordance with government guidance contained in the Framework and the Planning Policy Guidance.

The Central Bedfordshire Design Guide 2023 (DG) advises that ‘as a guiding principle, to be considered as proportionate the original building should not be added to by more than 60% of footprint, floorspace and volume. The impact of the extension in terms of massing and design will also be considered.’ The appellant and Council have set out what they consider would be the cumulative increase in footprint and floorspace that would result if the proposal was built in addition to the existing extensions, and their figures are consistent with one another.

The cumulative footprint that would result if the appeal proposal was built would be an approximate 78% increase on the original. Even on the consideration that part of the area that would become within the footprint is already covered with the roof of the existing garage, the figure of 60% set out in the DG would still be exceeded, albeit to a notably lesser extent. With regard to the increase in floorspace that would result, the cumulative increase over the original would be approximately 53% which would not exceed the figure in the DG. No figures relating to volume have been provided by either party.

In terms of its massing, the proposal would be modest in size, consisting of a small single storey extension to the rear of the existing workshop and the creation of a new roof structure above both the existing garage and workshop. There would be no particular bulk created by the proposal and neither the rear extension nor the works to the roof would significantly extend the built form beyond what presently exists. Its design would be simplistic and not imposing. When considered along with the previous extensions these works would not appear visually disproportionate in relation to what would have originally existed.

Taking all of these considerations together as a whole, I find that what is proposed would not result in disproportionate additions over and above the size of the original building, even when considered cumulatively with the other extensions that have taken place. The proposal therefore falls within the exception listed in paragraph 154c) of the Framework, and it would not be inappropriate development in the Green Belt. Consequently, the development would accord with Policy SP4 of the LP.

The proposed development would not be inappropriate development in the Green Belt. As such there is no requirement to undertake any further assessment of the impact that would arise upon the openness of the Green Belt.

The Council has raised no further concerns with respect to any other aspect of what is proposed, and I find no reason to disagree. Subject to conditions relating to the time period to commence development and the approved plans, which are required to provide certainty, and a condition relating to external facing materials, which is needed to ensure an acceptable visual appearance, the appeal should be allowed.