Appeal 3309415

The appeal is dismissed.

The main issues in this appeal are: • Whether the development would be inappropriate development in the Green Belt having regard to the National Planning Policy Framework and any relevant development plan policies; • The effect of the development on the openness of the Green Belt, and; • Whether the harm by reason of inappropriateness, and any other harm, would be clearly outweighed by other considerations so as to amount to the very special circumstances required to justify the proposal.

The appeal property is a large, detached house situated within a spacious garden, accessed from a private road and adjoining a wooded countryside edge. The appeal site is located in the Green Belt. Policy GBR1 of the East Herts District Plan 2018 requires proposals within the Green Belt to be considered in line with the provisions of the National Planning Policy Framework (the Framework).

Whilst new development is generally inappropriate in the Green Belt, as set out at paragraph 149 of the Framework, certain types of development 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. 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.

The Council estimates that the floor area of the appeal property, as originally constructed, was 170.7 sqm. The appeal property has been altered extensively over time, with the site’s planning history indicating that planning permission has previously been granted for two two-storey extensions, a rear dormer roof extension, and a single storey rear conservatory extension. The Council estimates that the appeal property has an existing floor area of 360.6 sqm, and therefore the existing permitted extensions and alterations have resulted in a cumulative increase of 111% relative to the floor area of the original dwelling.

The appellant suggests that the Council has underestimated the additional area of the existing dwelling, estimating that previous alterations have resulted in an increase in floor area of 122%. Despite discrepancies between the estimated floor area values, each serves to illustrate that past extensions and alterations have substantially increased the scale of the appeal property relative to the original building.

There is disagreement regarding the extent of the additional floorspace which would be constructed. However, both parties broadly agree on the estimated total floor area of the appeal property following implementation of the proposal. Using the appellant’s total floor area estimate (385.9 sqm) the proposal, along with previous alterations, would constitute an increase relative to the floor area of the original dwellinghouse of 215.2 sqm or 126%.

The appellant suggests that the proposed additional floor area equates to a minimal increase relative to the existing dwelling, and that through granting planning permission for past alterations the Council has accepted that previous increases in floor area were not disproportionate. However, in addition to the increased floor area, the proposal would create additional built volume, particularly at first floor level above the existing conservatory section and through the construction of a hipped roof above the proposed extension. Taken together, the cumulative effect of the proposal and past alterations would amount to a substantial addition to the property, which I find to be disproportionate over and above the size of the original building. For these reasons, the appeal proposal would be inappropriate development in the Green Belt which is, by definition, harmful.

Openness is an essential characteristic of the Green Belt that has both visual and spatial aspects. The main visual impacts of the proposal would be the additional massing of the proposed extension, particularly at first floor and roof level since much of the area of the ground floor footprint is occupied by part of the existing dwelling. The proposed extension would adjoin the existing two-storey brick projection and would be behind the conservatory, reducing its prominence. The rear garden is very large, and the appeal property is set down from a stepped terraced lawn. Boundary treatments include brick walls and tall vegetation. Beyond the rear garden are areas of woodland and the appeal property is distant from public spaces, such as the public highway. Views of the proposal would therefore be generally limited to spaces within the appeal property’s rear garden, and its visual impacts would be modest.

As discussed above, the proposed extension would be of two-storey height with a hipped roof. The proposal would widen the existing rear projection by around 2.5 metres and therefore the spatial impacts would be modest. Nonetheless, this increase in volume, height and massing relative to the existing dwelling would result in a harmful loss of openness, which weighs somewhat against the proposal.

Paragraph 147 of the Framework indicates that inappropriate development should not be approved except in very special circumstances. At paragraph 148, the Framework indicates that very special circumstances will not exist unless the potential harm to the Green Belt is clearly outweighed by other considerations.

The appellant asserts that the proposal would not harm the character and appearance of the dwelling or surrounding area. However, I do not consider that the absence of harm in this respect would clearly outweigh the small reduction in openness. Consequently, no very special circumstances exist.

As set out above, the proposal would constitute inappropriate development and there are no very special circumstances which outweigh the potential harm to the Green Belt. The proposal would therefore conflict with Policy GBR1.

The appeal site is within the [name] listed Registered Park and Garden of Goldings. Section 66 (1) of the Planning (Listed Building and Conservation Areas) Act 1990 requires special regard to be had to the desirability of preserving a listed asset or its setting or any features of special architectural or historic interest which it possesses. Paragraph 199 of the Framework states that when considering the impact of a proposed development on the significance of a designated heritage asset, great weight should be given to the asset’s conservation; the more important the asset, the greater the weight should be.

The significance of the Park and Garden arises from its undeveloped parkland and grounds relating to the Goldings estate. The appeal site has a clearly defined private curtilage which separates the site from the rest of the Park and Garden. As discussed above, the proposed extension would be situated within an enclosed position at the rear of the appeal property with limited views into the rear of the site. I consider the effects of the proposal upon the significance and special historic character and appearance of the heritage asset to be neutral.

For the reasons given above, having assessed the case against the development plan as a whole and having had regard to all other relevant material considerations, I conclude that the appeal should be dismissed.