Appeal 3296427

The appeal is dismissed.

In its decision notice the Council used an altered description of the proposed development from that given on the application form. There is no indication that this change was agreed with the appellant. Given that the application form accurately describes what is proposed I have used that description within my decision.

The main issues in the determination of the appeal are: i) Whether the proposed development would be inappropriate development in the Green Belt for the purposes of the National Planning Policy Framework (the 'Framework') and development plan policy; ii) The effect on the openness of the Green Belt; iii) The effect on the character and appearance of the area, including [name] historic park and garden; iv) If the proposal does amount to inappropriate development within the Green Belt, whether the harm by way of inappropriateness, and any other harm, is clearly outweighed by other considerations such as to amount to the very special circumstances needed to justify the development.

Development within the Green Belt is strictly controlled in order to preserve its key characteristics and functions, as set out at paragraphs 137 and 138 of the Appeal Decision APP/ X1925/D/22/3296427 Framework. New development is deemed to be inappropriate unless it falls within one of the exceptions listed at paragraphs 149 and 150. Of relevance to this appeal paragraph 149(c) allows for extensions to existing buildings, providing that they do not result in disproportionate additions over and above the size of the original building. The original building is defined as a building as it existed on 01 July 1948 or, if constructed after that date, as it was built. Saved Policy 2 of the North Hertfordshire District Local Plan (1996) (the LP) is broadly consistent with the aims of national policy, as is Policy SP5 of the emerging Local Plan (ELP) which has reached submission stage.

In some circumstances Local Plans set a limit, usually expressed in volumetric percentage terms, beyond which extensions will be considered to be disproportionate. In the absence of any specific criteria in this instance what amounts to a ‘disproportionate’ extension requires the exercise of judgement, as a matter of fact and degree. Factors such as size, volume, prominence, and overall scale will be relevant.

It is clear that the originally modest property has already been extended substantially. The rear extension permitted in 2010 allowed for two, two-storey, rear wings to be added at each end of the property and these have been joined by a single storey extension. In addition, a garage, car port and sizeable garden office have also been erected. Whilst the full details of the rationale for approving the garden buildings has not been provided I note that there is no specific allowance for new detached garden structures within the listed exceptions to ‘inappropriate’ development at paragraphs 149 and 150 of the Framework. However, it is common practice for ancillary structures to be considered as extensions under paragraph 149(c) where they would amount to a normal domestic adjunct. That would appear to be the case here. Consequently, the cumulative effect of all of the previous extensions and outbuildings, as well as the current appeal proposal, should be considered when making a judgement as to whether the development would be disproportionate, as compared to the original building.

The floor area of those extensions and outbuildings is greater than that of the original dwelling and whilst precise volumetric calculations have not been submitted, the combined mass is substantial compared to the scale of the original property. The development is also spread out across a much wider area of the site. In addition to the combined scale and volume the proposal would extend to the south and elongate the dwelling. That would further increase the coverage of built form when combined with previous extensions to the rear and outbuildings to the north.

The appellant has expressed the scale of the proposed extension as a percentage of the size of the garden. However, the required assessment is to compare the scale to the original building. Whilst the conservatory now proposed is not substantial, of itself, it would add to the cumulative impact of the previous development at the site. Given the substantial scale, footprint and coverage of existing extensions and outbuildings the extension would tip the cumulative extent of new development into what would clearly amount to a disproportionate addition in my view. Accordingly, the proposed development would not comply with the exception listed at paragraph 149(c) and would amount to inappropriate development, having regard to national and local

As set out above, openness is a key characteristic of the Green Belt. Assessment of the effect on openness has both a visual and spatial dimension. In visual terms, the proposal would be well-screened by mature boundary hedges and neighbouring residential development and would not be overly prominent in the wider landscape. Spatially, it would extend into space that is currently free from built development and would elongate the dwelling as described above. That would have some impact on the openness of the Green Belt in a physical sense, albeit that the effect would be limited and localised. Nonetheless, any harm to the openness of the Green Belt runs contrary to the aims of established planning policy and that is a matter that weighs against the development.

The appeal site sits within the registered park and garden at [name] which comprises the formal gardens associated with the main hall, as well as the planned, agrarian, parkland landscape which surrounds it. [address] clearly has a close historical association with the main house and is one of a number of residential properties within the estate.

Whilst the parkland landscape offers sweeping vistas and views, the immediate context around the site is more intimate, being bordered by the lane and other dwellings and converted properties. Moreover, the garden is enclosed by mature hedges. Consequently, the impact of the conservatory on the wider parkland landscape would be extremely limited in my view. I note concerns regarding reflective light from the proposed glazing but any impact would be very localised in extent and the structure itself would be seen against the backdrop of existing residential development. In any event, glazing is not an alien feature in the landscape; the surrounding buildings and the main house itself contain glazed facades as one would expect in residential buildings. Consequently, I am not convinced by the argument that glare, to the extent that it would be noticeable in any event, would cause demonstrable harm.

The design and appearance of the existing lodge is domestic in nature and the proposed design and materials, including the oak frame, would be sensitive to that context. Overall, the proposal would not cause harm to the character and appearance of the dwelling itself, nor would it have any discernible impact on the ability to appreciate and understand the significance of the surrounding gardens and parkland. In those respects the development would comply with the aims of Saved Policy LP19 of the LP, policy HE1 of the ELP and the principles set out within Chapter 16 of the Framework.

No other material considerations have explicitly been put forward by the appellant. I recognise that permitted development rights often exist to extend residential properties in the Green Belt but that is not the case here. Such rights were removed when the property was converted and there is no fall-back position against which to compare the proposed development.

The proposed development would constitute inappropriate development and, by definition, would be harmful to the Green Belt by way of that Appeal Decision APP/ X1925/D/22/3296427 inappropriateness. It would also have a limited but negative impact on the openness of the Green Belt. Paragraph 148 of the Framework requires that substantial weight is given to any harm to the Green Belt. The proposal is also contrary to the development plan in those respects.

I have found no harm in relation to the character and appearance of the area and the registered park and garden. However, that would be expected of any development and the absence of harm is not a matter that has positive weight in favour of the proposal.

As set out at paragraph 148 of the Framework, inappropriate development should not be approved unless the harm to the Green Belt, and any other harm, are clearly outweighed by other considerations such as to amount to the very special circumstances needed to justify a proposal. Given the absence of any other matters put forward by the appellant it is clear that such circumstances do not exist in this case. Thus, there is nothing to indicate that a decision should be taken other than in accordance with the Development Plan and I shall dismiss the appeal.