Appeal 3319828

The appeal is dismissed.

The main issues are: -whether or not the proposal is inappropriate development in the Green Belt; -the effect on the openness of the Green Belt; -the effect of the proposal on the character and appearance of the area including the Heronsgate Conservation Area; and -if the development is inappropriate, its effect on openness and whether the harm by reason of inappropriateness, and any other harm, is clearly outweighed by other considerations, so as to amount to the very special circumstances required to justify the proposal.

The appeal site comprises a dwelling which is situated in the Green Belt. The National Planning Policy Framework (the Framework) identifies that the fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open. It goes on to state that inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances.

Policy CP11 of the Three Rivers District Council Core Strategy (CS) (2011) has a general presumption against inappropriate development that would not preserve the openness of the Green Belt, or which would conflict with the purpose of including land within it. Policy DM2 of the Three Rivers District Development Management Policies Local Development Document (TRDMP) (2013) and the Framework both set out that new buildings are inappropriate subject to certain exemptions, one of which relates to extensions to buildings that are not disproportionate additions over and above the size of the original building.

The appeal property comprises a large dwelling which has been extended in the form of 2-storey and double garage extensions and a conservatory. The proposal would involve the demolition of the conservatory and the erection of a part-single, part-2 storey extension to the rear.

Neither the Framework nor the development plan define what it means by disproportionate. The Council make reference to Supplementary Planning Guidance (SPG) which stated that extensions resulting in a cumulative increase in floor space of over 40% compared with the original dwelling may be disproportionate, however the Council acknowledge that this SPG is of limited weight. Consequently, an assessment of whether a proposal would amount to a disproportionate addition over and above the size of the original building is a matter of planning judgement.

In the context of the Framework the glossary advises that ‘original building’ refers to a building as it stood on 1 July 1948 or as constructed if built after that date. Whilst the appellant states that the proposal would result in an increase in volume of approximately 14% compared to the existing building, the main parties are in agreement that the existing building has undergone considerable extensions. Based on the evidence before me these extensions do not appear to form part of the original building as defined by the Framework.

The cumulative effect of the appeal proposal, plus the previously built extensions would take the new floorspace to approximately 118% of the original floor area. This represents a substantial and noticeable increase in the floor space of the original building. Furthermore, given the depth and layout of the proposed extension, I give limited weight to the appellants’ comments that the footprint of the dwelling would only fractionally exceed the northwest extremity of the existing footprint of the dwelling.

Therefore, the proposal would result in disproportionate additions over and above the size of the original building, in conflict with TRDMP Policy DM2 and the associated aims of the Framework.

The Framework states, at Paragraph 137, that the fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open. The essential characteristics of Green Belts are their openness and their permanence. Openness has both spatial and visual aspects.

The proposed increase in depth of the dwelling, along with the associated increase in massing and built form at first floor level, would result in a dwelling which would appear bulkier than the existing dwelling. This increase in the overall size and volume would spatially reduce the openness of the Green Belt.

The appeal building is contained within a plot defined by dense boundary vegetation and there would be limited views of the proposed extension from Cherry Tree Lane. However, there would be glimpses of the extension from neighbouring land through boundary vegetation and therefore, whilst the degree of visibility of the extension would not be widespread, there is harm to visual openness.

The removal of the conservatory would reduce the building’s width, increasing openness to the western part of the site. However, this would not compensate for the loss of openness to the rear of the building arising from the increased depth and massing of built form here, in particular given the scale and height of the proposed extension in comparison to the conservatory. Therefore, the proposal would be moderately harmful to openness.

I therefore conclude that there is a loss of openness in the Green Belt which conflicts with Paragraph 137 of the Framework and is contrary to CS Policy CP11 and TRDMP Policy DM2 which seek to preserve the openness of the Green Belt. Paragraph 148 of the Framework advises that substantial weight is given to any harm to the Green Belt. Therefore, although the effect is moderate, this is to be given substantial weight.

The site is located in the Heronsgate Conservation Area (CA). In accordance with the duty imposed by section 72(1) of the Planning (Listed Building and Conservation Areas) Act 1990 I am required to pay special attention to the desirability of preserving or enhancing the character or appearance of the conservation area. Moreover, Paragraph 199 of the Framework states that when considering the impact of new development on the significance of a designated heritage asset, great weight should be given to the asset’s conservation.

The CA is made up of large houses with prominent hedgerows and trees. In my view, the CA derives its significance from the pattern of buildings and the spaces around them, which reflect its origins as a Chartist settlement. The siting of [address] within a large, landscaped plot positively contributes to the significance of the CA.

The Heronsgate Conservation Area Appraisal (2012) (CAA) provides guidance for new development in the CA. Amongst other things it states that all forms of new development should reinforce the scale and massing of surrounding buildings and that new development should not be out of scale with existing building typical of the CA by way of its height, floor levels, size of windows and doors and overall massing.

The appeal proposal would add significant bulk and massing to the existing property. By virtue of its scale, the extension would fail to appear as a subservient addition, introducing a significant change to the appearance of the building, in particular in views from the rear elevation where the discordant roof form and fenestration would be evident. This would be in conflict with the design guidance set down in the CAA.

Nonetheless, in this case, the proposed development would be at the rear of the property and would be located some distance from the site boundaries. The resultant increase in scale and massing of the appeal property would not be perceptible from the street scene. Thus, whilst sizeable, the proposed extension would have limited effect on the street scene, and the removal of the conservatory would bring some symmetry back to the front elevation. Therefore, considered overall, the proposal would not alter the positive contribution the appeal property makes to the significance of the CA. Furthermore, whilst the extended property would be larger than the existing dwelling, there is no compelling evidence before me that it would be at odds with the scale of surrounding buildings.

In light of the above, the change to the character and appearance of the appeal property would be insufficient to cause wider harm to the character and appearance of the CA. I therefore find that the proposal would preserve the character and the appearance of the CA, and its significance would not be harmed.

[name] have identified conflict with the guidance set down in the CAA, in this site-specific circumstance I have found that the character and appearance of the CA would be preserved. Therefore, the proposal would not be contrary to [name] CP1 and CP12 and [name] DM1, DM3 and Appendix 2 which together seek to protect local character and require heritage assets to be conserved and enhanced. I also find no conflict with Section 16 of the Framework, which supports the conservation of heritage assets.

My attention has been drawn to an appeal decision for the erection of a conservatory at the appeal site1 in which the Inspector found that the conservatory would be a minor ancillary addition which would have very little effect on the space around the house or the openness of the surroundings, observing that it would not be readily visible from outside of the appeal site.

The full details of this case are not before me and thus it is unclear whether this permission relates to the conservatory which has been erected, or whether this permission is capable of implementation. Nonetheless, the Inspector’s decision refers to the conservatory as having a volume of 85 m3. The proposed extension would result in a far greater increase in the amount of built form than this conservatory, in particular given the differences in size and height. Therefore, whilst I acknowledge that views of the appeal proposal from outside of the appeal site would be similarly limited by boundary vegetation, the decision to which my attention has been drawn would not result in a similar increase in the size and volume of the dwelling and thus would not have a comparable harmful spatial effect on the openness of the Green Belt. I therefore give limited weight to this decision.

My attention has also been drawn to a planning permission2 for the demolition of existing conservatory, construction of single storey rear extension and conversion of garage into habitable accommodation. There is no dispute between the main parties as to whether this consent could be implemented although I have limited information about whether there would be an intention to build that extension if this appeal were dismissed. However, there would seem a greater than just theoretical possibility that this alternative would take place.

The extension approved under that permission is single storey in height and does not project beyond the existing rear elevation of the dwelling and thus would have less impact upon the openness of the Green Belt than the appeal proposal. Therefore, if that permission were implemented, it appears that it 1 T/APP/P1940/A/99/1016850/P8 2 Application reference 23/0763/FUL would be less harmful to the openness of the Green Belt. Thus, the prospect that this, less harmful, alternative scheme could be implemented does not weigh in favour of the current proposal.

No objections were received in relation to the appeal proposal from interested parties and the Council found that the proposal would not result in harm to the living conditions of the occupiers of neighbouring properties. However, the absence of harm in these regards does not weigh in favour of the proposal, as it would be required in any event. Therefore, these matters are neutral in the

I have found that the proposal would not result in harm to the character and appearance of the CA. Nonetheless, it would be inappropriate development in the terms set out by the Framework and would result in a harmful loss of openness to the Green Belt. The Framework requires that substantial weight should be given to any harm to the Green Belt.

For the reasons set out above, the harm to the Green Belt would not be clearly outweighed by the other considerations. Therefore, the very special circumstances required to justify a grant of planning permission have not been demonstrated.

The proposed development conflicts with the development plan when considered as a whole and there are no material considerations, either individually or in combination, which outweigh the identified harm and associated development plan conflict. I therefore conclude that the appeal should be dismissed.