Appeal 3298249

The appeal is allowed and planning permission is granted for extension to rear, new interior layout and roofline alterations at [site address] in accordance with the terms of the application, Ref 21/04263/HOUSE, dated 22 December 2021, subject to the following

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: BT84 Sheet 1, BT84 Sheet 3 & BT84 Sheet 4.

The external surfaces of the development hereby permitted shall be constructed in the materials specified on the application form.

Following the refusal of the appeal application the Council subsequently granted a lawful development certificate for a ground floor rear extension, without the roof alterations proposed in the current appeal1. That rear extension had been constructed at the time of my site visit. Notwithstanding that, I am required to determine the appeal as submitted and I have considered the proposal, including the proposed ground floor extension within my decision.

The site is located within the Metropolitan Green Belt. The Council has raised no issues in terms of the design or appearance of the proposal or its effect on neighbouring living conditions and I see no reason to disagree having visited the site. 1 22/01043/LDCPR

Therefore, the main issue in dispute is whether the proposal, in combination with previous extensions to the property, would represent a disproportionate addition to the dwellinghouse so as to amount to inappropriate development within the Green Belt.

Harewood is a detached bungalow which forms part of a ribbon of individually designed properties stretching out along [site address] . The dwellings are all set back from the Lane with generous gardens to the rear resulting in a low density form of residential development.

Policy GB1 of the [name] and Development Management Plan (2015) (SADMP) relates to residential extensions within the Green Belt and states that proposals will be permitted where they meet three main criteria, relating to the lawfulness of the existing dwelling; a requirement that the design responds to and is subservient to the form of the original dwelling and a requirement that total floorspace of the proposal, along with previous extensions, does not result in an increase in floorspace of more than 50% above that of the original dwelling.

The policy is essentially the local interpretation of paragraph 149(c) of the National Planning Policy Framework which states that extensions or alterations to buildings are not inappropriate provided that they do not result in disproportionate additions over and above the size of the original building

There is no dispute that the existing dwelling is lawful and permanent in nature. With regard to the second criteria the single storey rear extension is set down from the ridge of the dwelling and does not project by an excessive distance when compared to the original depth of the bungalow. From the front, the proposed roof alterations would not result in any significant visual change, save for a modest increase in roof height of the currently lower section of the building which adjoins the garage.

The remainder of the roof alterations would be discreetly tucked to the rear and the Council has raised no issue with those alterations in design terms. I noted a very similar roof form on a neighbouring property. Overall, even when combined with the previous extension to form a single garage, the proposed alterations would remain subservient to the original property in terms of form, volume and visual scale.

The parties differ in terms of how the additional floorspace should be calculated in terms of the third criteria of policy GB1, specifically over the degree to which the accommodation in the roofspace should be calculated. The upper floor is already in use as residential accommodation, housing a bedroom, with a rooflight in the rear roofslope. Thus, much of the upper floor could already be considered to contain floorspace. The current proposals do not increase the footprint of the upper floor but do have the effect of raising the headroom within the space to the rear.

Policy GB1 does not distinguish between floorspace and usable floorspace, nor does it set a head height above which floorspace is considered to count towards an increase in terms of the policy. It is common for cupboards and storage to be placed under the eaves which adds to the accommodation, even with limited headroom. Thus, it could reasonably be argued that the roof alterations do not result in an increase in floorspace at all. Rather, it merely increases the usability of the existing space.

I am also mindful of the preamble to policy GB1, at paragraph 7.15, which explains the context of how the local policy has evolved. That acknowledges that there will be situations where a loft conversion can increase the size of a building without affecting the external size of a building, such as a conversion only involving rooflights. The paragraph goes on to state that ‘Conversely development can occur that adds significantly to the physical size of the building without affecting floorspace, for example a replacement roof that is much bulkier but does not include extra accommodation’.

To my mind that would seem to apply to situations where an upper floor within the roofspace is already in use but the roof is remodelled to provide additional headroom as is the case in this instance. Thus, having regard to the wording of the policy, the preamble, and the fact that the upper floor is already in residential use, I find that the first-floor alterations would not result in an increase in floorspace.

Moreover, it appears that is precisely why criteria b) was added to policy GB1 when the policy was reviewed as part of the development of the SADMP. The preamble to the policy explains that previous local plans contained a policy solely relating to additional floorspace. Under that policy a development that created significant extra volume but no additional floorspace would technically comply with the requirement even though it may have an adverse effect on the openness of the Green Belt. Consequently, criteria b) was added which allowed for consideration of volume, subservience and proportionality. Both elements need to be considered for a development to be deemed acceptable.

Given that the roof alterations would not increase floorspace, the increase in this instance relates to the rear extension. The appellant contends that the original dwelling had a floorspace of 119sqm and that the ground floor rear extension would have a floorspace of 45.9sqm. When added to the garage, the combined increase in floorspace would be 64.2sqm, representing a 54% increase in floorspace. The Council contends that the original dwelling had a floorspace of 100.4sqm. The difference between the two would appear to be down to the fact that the appellant has factored in floorspace for the upper floor where the Council has not.

It is common for bungalows of that style to contain upper floor accommodation and the appellant’s position is not unreasonable. Consequently, the percentage increase in floorspace is only marginally over the 50% limit set by policy GB1. In any event, the policy is permissively worded in stating that proposals that comply will be approved. It does not automatically follow that a minor addition above 50% should automatically be refused. In this case, the overall volume is proportionate and subservient to the original building and a very strong fall-back position exists in relation to the almost identical ground floor single storey extension which has already been constructed. The roof alterations themselves do not add floorspace for the reasons given.

For the reasons given, I am satisfied that the external increase in volume would be modest and not excessive when compared to the scale of the original property. In that context, notwithstanding the minor infringement beyond the 50% limit in floorspace set by policy GB1, the proposal would not result in a disproportionate addition to the original dwellinghouse and would not, therefore, amount to inappropriate development within the Green Belt. Thus, I find no conflict with the aims of the development plan as a whole or the Framework both of which aim to preserve the openness of the Green Belt.

In addition to the statutory time limited commencement condition, a condition is necessary to ensure that the development complies with the submitted plans, in the interests of certainty. A condition to ensure suitable materials are used in the external surfaces is also necessary in the interests of the character and appearance of the area.

For the reasons given above the proposal would not amount to inappropriate development within the Green Belt. In the absence of any other harm I shall allow the appeal subject to the conditions set out above.