Appeal 3329306

The appeal is dismissed.

Since the appeal was lodged, the Council has adopted the Welwyn Hatfield Local Plan 2016 – 2036 (LP). As a result, the ‘draft’ policies referred to in the reasons for refusal have superseded the ‘saved’ policies of the Welwyn Hatfield District Plan which were cited in the decision. The appellant was consulted on the newly adopted policies, and the comments received have been taken into account in my assessment of the appeal.

A revised National Planning Policy Framework (the Framework) was published in December 2023, but as the policies of most relevance to this appeal have not fundamentally changed, further comments have not been sought from the parties. I have referred to the current paragraph numbers of the Framework in this decision.

The main issues are: • whether the proposal is inappropriate development in the Green Belt (GB) for the purposes of planning policy set out in the Framework and the development plan; • the effect on the openness of the GB; • the effect on the appearance of the appeal property and the character of the area; and • if the development is inappropriate, 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 necessary to justify the development.

The appeal property is a detached chalet-style dwelling set within a ribbon of housing in the Green Belt. Although the dwellings are of similar scale, most have been extended, including roof extensions and dormer windows. The appeal property is the replacement of a previous property, granted in 1989.

The Framework confirms that inappropriate development is, by definition, harmful to the Green Belt, and should not be approved except in very special circumstances. An exception which is not to be regarded as inappropriate is 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. The glossary to the Framework defines “original” as the building as it existed on 1 July 1948 or, if constructed after 1 July 1948, as it was built originally.

A footnote to LP Policy SADM 34 expands upon this definition, adding that, where an existing building has replaced an original building, any increase in size over the original building will be taken into account in assessing cumulative impact. Having regard to recent case law1 cited by the Council, and the clarifying footnote to this policy, I agree with the Council’s view, rather than the appellant’s, that the ‘starting point’ against which to assess the appeal proposal is the dwelling that existed on site before the replacement was built under permission S6/1989/0267/FP.

I note the appellant’s view that a significant weakness of the adopted policy is that details of dwellings long since replaced are not available, but the Design & Access statement submitted with the planning application gives the footprint of the pre-1989 dwelling as 83sqm. The Council’s delegated report indicates that, following a review of the planning history, it considers that the original building had a floor space of approximately 110 sqm., and that the subsequent replacement dwelling represented an increase in floorspace of approximately 56.8%. The Council considers that, cumulatively, the appeal proposal would represent an approximate 90% increase over the original floor space. The appellant disputes this, suggesting the increase to be 70%.

This increase in floorspace is not definitive, but the appellant acknowledged in his response to the Local Plan adoption that the proposal would be considered disproportionate under Paragraph 154(c) of the Framework and the now adopted Policy SADM 34.

The proposal would involve a significant increase in floorspace compared to the original dwelling, but would also appear visually larger than the existing building due to the bulk added by the raised height, half-hipped roof form, dormer windows and enlarged gables. As a matter of fact and degree, I conclude that, considered individually or cumulatively, the proposal would result in disproportionate additions over and above the size of the original 1 Guildford Borough Council v Secretary of State for [name], Housing and Communities & Anor [2023] EWHC 575 building. It would therefore be inappropriate development that is, by definition, harmful to the GB, in conflict with the Framework and LP Policy SADM 34.

The proposal would materially add to the bulk of the roof of the dwelling, and would result in a more dominant property, with a consequent harmful effect on the openness of the GB. However, being contained within the existing footprint of the building, and within a ribbon of established housing, I consider this effect on openness to be reasonably limited.

The group of dwellings within which the appeal property is set vary in design, size and scale. Some have been extended, and dormer windows are commonplace. Extensions at [address] (No.5) share some similarities with the appeal proposal, although with a strong front gable, it is not the prevailing style or scale of extension in the street scene.

The Council does not oppose in principle the increase in ridge height, change in roof form or the front and rear dormer windows. Having regard to the variety of extensions in the vicinity, I agree with this view.

I appreciate that the intention is to make an aesthetic improvement to the dwelling, but the large size and extensive glazing of the proposed front and rear gables would create imposing features on the dwelling, albeit the rear would have more limited impact on the street scene. The Council considers that the gables would be larger than others in the vicinity, but on the information supplied I cannot assess this with any certainty; viewed on the ground, the proposed front gable would not appear to be dissimilar in size to that at No.5. However, the proposed front gable would be materially different in design and detailing from No.5, with the latter more reflective of the host dwelling and the traditional detailing of others in the street scene. In contrast, with its extensive glazing, the proposed front gable would ‘draw the eye’ and create a visually dominant feature on the dwelling that would be incongruous in the street scene. Combined with the rear gable, they would emphasise the increased bulk of the dwelling at first-floor level.

I therefore conclude that the proposal would detract from the character and appearance of the appeal dwelling and the street scene, in that it would fail to relate well to the character and proportions of the existing building, the surrounding context and the street scene in terms of mass, scale, detailed design and materials, as required by LP Policy SP 9; and would conflict with the Council’s Supplementary Design Guidance (SDG), which amongst other criteria requires extensions to be designed to complement and reflect the design and character of the dwelling and be subordinate in scale, and to respect and relate to the character and context of the area in which it is proposed. For the same reasons, it would not accord with the design objectives of the Framework.

The Framework advises that inappropriate development is, by definition, harmful to the GB and should not be approved except in very special circumstances. It confirms that substantial weight should be given to any harm to the GB, and that ‘very special circumstances’ will not exist unless the potential harm to the GB by reason of inappropriateness, and any other harm resulting from the proposal, is clearly outweighed by other considerations. I now turn to the arguments made in favour of the appeal development.

The appellant has placed much weight on extensions built at [address], which the appellant advises stem from planning permission S6/2006/1356/FP in 2006. As noted above, I do not consider this development to have the same visual impact as the gables proposed in this case, and moreover, the front gable at No.5 is not typical of the prevailing scale and form of roof extensions in this part of [address]. [name] accept that the development was assessed against the SDG which remains in place, it pre-dates current adopted local and national planning policies. Given these circumstances, that development offers only modest support to the appeal.

[name] was issued for a single-storey 8m deep rear extension to the appeal property in April 2023. On the ground, it does not appear that works have commenced, but its construction is a realistic ‘fallback’ position. I share the appellant’s view that this would have a greater impact on the openness of the GB than the appeal scheme, and would be greater in footprint, floorspace and volume. In some aspects, its visual and functional relationship with the dwelling would be poorer, although being at the rear of the property I consider that it would have less visual impact on the character and appearance of the street scene than the proposal.

However, no mechanism has been put forward to prevent the proposal and a Permitted Development (PD) scheme both being constructed: a condition to remove PD rights would not come into force unless and until this appeal permission were implemented, and in the interim an alternative PD extension could be built (albeit of lesser size and therefore impact than the [name] scheme). A condition that would allow either this appeal scheme or the [name] scheme to be built, but not both, could not prevent the implementation of an alternative PD scheme before the construction of the appeal development. I cannot therefore place weight on the appellant’s suggestion that conditions could be imposed preventing the construction of both the appeal proposal and [name] scheme, and the removal of PD rights.

The appellant advises that the proposal would have improved environmental performance as a result of the replacement of the roof. This could offer support to the proposal, but in the absence of more detailed information it is not clear what the results would be, and whether or not such improvements could be achieved without such extensive alterations.

The appellant has drawn attention to proposals at [address], and the weight ascribed to other local extensions in the Council’s assessment (examples of which were listed in the Planning Statement). However, full details of the case made in support of that scheme have not been supplied, and as such I have found that the reasoning in that case offers only limited support for this proposal.

Having balanced the various matters, other considerations do not clearly outweigh the harm to the GB by reason of inappropriateness, and harm to its openness; and, harm to the character and appearance of the dwelling and area. The very special circumstances necessary to justify the development do not exist. Consequently, the proposal fails to comply with the Framework and LP Policy SADM 34. I conclude that the appeal should be dismissed.