Appeal 3310838

The appeal is allowed and planning permission is granted for conversion of existing detached garage to gym and home office, including raising roof to create second floor at [site address] , Denham, Buckinghamshire [postcode] in accordance with the terms of the application, [name]/22/2584/FA, dated 20 July 2022, 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: 01 [name] 2022; 02 [name] and [name] 2022; 03 PL Site and [name] 2022; 10 [name] 2022; 11 [name] 2022; 12 [name] 2022;

The main issue in this appeal is whether the proposal would be inappropriate development in the Green Belt having regard to the National Planning Policy Framework (the Framework) and relevant development plan policies.

Policy GB1 of the South Bucks District Local Plan 1999 (LP) generally restricts development in the Green Belt, permitting proposals for extensions to existing buildings which harmonise with the scale, height, form and design of the original building. In addition, LP Policy GB10 supports extensions in the Green Belt to provide ancillary accommodation where the development would meet certain criteria which generally seek to ensure the proposal is small in scale and preserves the character and appearance of the area.

The Framework indicates policies should be afforded due weight having regard to the degree of consistency with it. At paragraph 137, the Framework describes the essential characteristics of Green Belt being its openness and permanence and states the fundamental aim of Green Belt policy is to keep land permanently open. The LP pre-dates the Framework’s publication but also applies strong restraint upon development in the Green Belt.

Paragraph 149 of the Framework regards the construction of new buildings within the Green Belt as inappropriate but provides certain exceptions that are not inappropriate. This includes 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.

Whether the proposal would result in “disproportionate additions” is a more stringent test than criteria set by Policies GB1 and GB10. Therefore, the LP is not wholly consistent with the Framework thus reducing the weight which can be afforded to relevant policies. The provisions of the Framework therefore carry significant weight in my decision.

The existing double garage is a modern, detached building with a pitched roof. The proposal would raise the height of the roof by 1m to provide additional headroom to create a new first floor. Through the addition of the first floor, the proposal would double the garage’s floor area. However, the proposal would raise the height of both the eaves and ridge, thereby retaining the pitch angle of the existing roof, and would not provide standing headroom across the full extent of the first floor.

Through raising the roof height, the proposal would increase the built volume of the building by around 22%. Since the first floor would be accommodated within the roof space, the proposed development would not have the appearance of an additional storey and the garage would retain the external form of a single-storey building.

Neither the Framework nor development plan provide a specific test for determining whether an extension or alteration is disproportionate and therefore whether the proposal would result in disproportionate additions is a matter of planning judgement. Whilst the insertion of the first floor would significantly increase the floor area, the increase in height and volume would be modest relative to the original building. For this reason, it is my judgement that the proposal would not amount to disproportionate additions over and above the size of the original building.

The garage is located at the end of a large rear garden around 40m from the host dwelling. Due to the limited scale of the proposed development and the large distance from the host dwelling, the proposal would retain the appearance of an ancillary building that is subordinate in scale and mass and would not appear to have a competing relationship with the main dwelling or surrounding buildings.

The garden is enclosed by a tall close-boarded fence and the garage is accessed from a private road. The proposal is not visible from publicly accessible spaces, such as the public highway, and would not therefore appear strident or visually obtrusive in the landscape.

For these reasons, the proposed development would comply with paragraph 149 c) of the Framework and would not be inappropriate development within the Green Belt. The proposal would comply with LP Policy GB1 which permits proposals which would not adversely affect the character or amenity of the Green Belt and would accord with LP Policy GB10 which requires ancillary buildings to be of small size in relation to the size of the dwelling and residential curtilage.

The appeal site is within the Denham Conservation Area (CA) and the garage is located within the garden of [address], a [name] listed building. Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 requires special attention be had to the desirability of preserving or enhancing the character or appearance of the CA, and Section 66(1) requires I pay special regard to the desirability of preserving a listed building or its setting or any features of special architectural or historic interest.

The CA is an archetypal English village with an ancient parish church and churchyard, historic cottages, a country house set in a park, village pubs, and old farm buildings, set against a rural backdrop. This character and appearance contributes to the CA’s significance. [address]’s special architectural and historic interest is derived from its appearance as a 17th century property, re-fronted in the 18th century with red brick elevations under an old, tiled roof.

The garage is distant from the listed building of [address] and is sited at its rear where it is partly screened by boundary treatments and trees. Therefore, the proposal would not impact on the listed building’s setting. Whilst the workshops and barns in the lane nearby contribute to the character and interest of the CA, the existing modern garage makes no significant contribution to the CA and the proposal is modest in scale. The proposal would not therefore have an adverse impact on the CA’s character. For these reasons, the proposal would preserve the character and appearance of the CA and the special architectural and historic interest of the listed building.

In addition to the standard time limit of the planning permission granted, in the interests of certainty I have attached a condition specifying the approved plans.

Following conversion, the garage building would provide a home gym and home office for use by the occupants of the main dwelling. The Council has suggested a condition requiring the building be used solely for purposes ancillary to the main dwelling. However, change of use of the building would require grant of planning permission, and paragraph 54 of the Framework indicates planning conditions should not be used to restrict national permitted development rights unless there is clear justification. For these reasons, I do not consider the suggested condition necessary to make the development acceptable in planning terms, and therefore have not applied it to my decision.

For the reasons given above, having regard to the development plan taken as a whole, and all other relevant material considerations, I conclude the appeal should be allowed.