Appeal 3367304

The appeal is dismissed.

The main issues are: firstly, whether the proposed development would amount to inappropriate development in the Green Belt, having regard to the National Planning Policy Framework (NPPF), 2024, and any relevant development plan policies; secondly, the effect on the openness of the Green Belt; thirdly, the effect on the character and appearance of the host dwelling and the surrounding area; fourthly, the effect on the living conditions of occupiers of [address] with regard to light; and lastly, if the proposed development would amount to inappropriate development, whether the harm by reason of inappropriateness and any other harm is clearly outweighed by other considerations, such as to amount to the very special circumstances necessary to justify the development.

The appeal dwelling is a post war detached house on a large plot. It is one in a low density cul-de-sac of some 17 dwellings of various age, scale and design, located in a rural, mostly undeveloped area within the Green Belt. The dwelling has been extended in the past through single and two storey extensions to the rear.

The NPPF 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. For extensions and alterations to buildings, paragraph 154 c) states that these should not result in disproportionate additions over and above the size of the original building. “Original building” is defined in the NPPF as a building as it existed on 1 July 1948 or, if constructed after 1 July 1948, as originally built.

Policy CS5 of the adopted [name] 2006-2031 (CS), 2013, states that the Council will apply national Green Belt policy to protect the openness and character of the Green Belt. Saved Policy 22 of the Dacorum Borough Local Plan 1999-2011 (LP), adopted 2004, allows for extensions up to a 30% increase in floor area. This policy is not wholly consistent with the NPPF and is accorded limited weight.

Although the size of the original dwelling is uncertain, the planning history confirms that a number of extensions have been added. The appellant suggest that the original building had a floor area of some 169m2 and that there have been additions of about 51m2, resulting in an increase of some 30%. In the context of the evidence and in the absence of any alternative figures these appear reasonable estimates.

The appellant estimates that the proposed extensions and alterations would result in an overall addition of some 163.7m2, resulting in an increase in floor area over and above the original dwelling of some 96.8%, almost doubling its size. The appellant does not disagree with the Council that this would amount to a disproportionate increase over and above the size of the original dwelling and I agree that it would. Exception c) as set out in paragraph 154 of the NPPF would not therefore apply.

However, the appellant suggests that the exception set out in paragraph 154 g) would apply because, it is suggested, the land comprises previously developed land (PDL) and the proposal is for its partial or complete redevelopment. The Council does not accept either that the land meets the NPPF definition of PDL because, it suggests, it lies within a built-up area where residential gardens are excluded from the definition, or that the proposed extensions and alterations amount to redevelopment.

In the absence of compelling evidence to the contrary and on balance, I agree with the appellant that, as a matter of fact, the appeal site does not appear to lie within a built-up area. A built-up area would usually bring to mind a place of some scale with a high density of buildings. The full NPPF definition which gives other examples of excluded land in built-up areas as “parks, recreation grounds and allotments” appears to confirm that the type of built-up area envisaged would be more akin to a town or cohesive village than a small enclave of dwellings in an otherwise mostly open, rural settling.

Turning to the second matter of whether the proposed development would amount to “partial or complete redevelopment of PDL”, this is, in my view, a matter of fact and degree. Redevelopment of land would generally encompass the construction of new buildings, typically after demolition of previous ones. The appellant argues that the proposals include partial demolition and new construction. However, whilst previous extensions would be demolished and replaced with larger ones, the original dwelling would be altered but remain intact. What is proposed therefore appears to be essentially the extension and alteration of the original building, rather than amounting to either the partial or complete redevelopment of the land. In consequence, I conclude that the proposed development would not fall within the exception set out in paragraph 154 g) of the NPPF.

It is concluded on the first main issue that as neither exception 154 c) or g) apply, the proposed development would be inappropriate development in the Green Belt. The NPPF advises that substantial weight should be given to any harm to the Green Belt, including that by reason of inappropriateness.

The NPPF states that the essential characteristics of Green Belts are their openness and permanence. Openness has a spatial and visual aspect. The substantial increase in the depth of the dwelling at first floor and roof height would be clearly visible on entering [site address] from [address] and would reduce the openness to the rear of the dwelling and partially close the visual gap between the appeal dwelling and [address], through which woodland to the rear of the site is visible. The extensions would also be clearly visible from neighbouring gardens. Overall, this would have a moderate effect on openness, materially detracting from both the visual and spatial openness of the area.

It is concluded on the second main issue that the proposed development would, result in moderate harm to the openness of the Green Belt. The NPPF makes clear that substantial weight should be given to any harm to the Green Belt and the loss of openness therefore weighs heavily against the proposed development.

The appeal dwelling is a two storey house in a street of dwellings of mixed scale and design, including smaller chalet bungalows. However, I find no issue in principle with it being extended in a way that enlarges it since the character of the street scene is already one of variety rather than uniformity. The proposed extensions have been generally well designed and I find that the side extension with its mono-pitched roof, the proposed porch and the two storey front extension with its well-proportioned width and limited depth would all harmonise with the host dwelling. The rear elevation would also have a pleasing and coordinated appearance.

Nevertheless, the depth of the two storey rear extension would be similar to the depth of the original dwelling. Coupled with the front extension, this would result in an excessive depth of extensions at first floor and roof level that would dominate the dwelling. Moreover, they would be readily apparent in views from [site address] and the junction with [address]. The significant depth above ground floor would be uncharacteristic in [site address] and in this prominent location would detract from the established pattern of development.

It is concluded on the third main issue that the proposed two storey rear extension would have a materially harmful effect on the character and appearance of the host dwelling and the street scene of [site address] . In consequence, it would conflict with Policies CS11 and CS12 of the CS and saved Appendix 3 of the LP. Taken together and amongst other things, these expect a high quality of design that integrates with the streetscape character, enhances spaces between buildings and general character and respects adjoining properties in terms of scale, height and bulk.

At the time the original application was decided, the Council had insufficient information to determine the effect of the proposed extensions on light reaching habitable rooms in the adjacent dwelling, [address]. A daylight/sunlight survey, undertaken by [name] in June 2025 and submitted with the appeal concludes that acceptable levels of daylight and sunlight will be retained, in accordance with the BRE guidelines and that there would be no material reductions in daylight or sunlight at [address].

It is therefore concluded on the fourth main issue that there would be no materially harmful effect on the living conditions of occupiers of [address] with respect to light. In consequence, the proposed development would comply with CS Policy CS12 insofar as it expects development to avoid loss of daylight and sunlight to surrounding properties.

The appellant draws my attention to a fallback position which, it is suggested might amount to the very special circumstances necessary to justify the proposal. This would comprise an extension and an outbuilding, constructed under permitted development rights. However, even if the proposed 8m single storey rear extension would fall within permitted development rights, and the Council raises doubts regarding this owing to existing rear extensions, I am not convinced that it and a detached outbuilding would provide suitable alternative accommodation to that contained in the appeal proposal, which includes significant additions at first floor. Neither would the proposed single storey additions have the same level of effect on the openness of the Green Belt. I do not therefore find that the permitted development options would provide a realistic or more harmful fallback, and I afford this matter limited weight.

Accordingly, it is concluded on the fifth main issue that, in the final balance, the other considerations would not clearly outweigh the harm to the Green Belt through inappropriateness and loss of openness and the other harm to the character and appearance of the host dwelling and surrounding area. In consequence, the very special circumstances necessary to justify the development do not exist. The proposed development would therefore conflict with CS Policy CS5 and LP saved Policy 22 and with national policy set out in the NPPF, 2024.

For the reasons set out above and having regard to all other matters raised, including third party representations, I conclude that the appeal should be dismissed.