Appeal 3314411

The appeal is dismissed.

The Council’s decision notice refers to saved policies of the Welwyn Hatfield District Plan 2005 and a policy contained within the Welwyn Hatfield Draft Local Plan Submission 2016. The Welwyn Hatfield Borough Council Local Plan 2016 – 2036 (LP) was adopted on 12 October 2023. The Council has provided the revised policies and the appellant has been given the opportunity to make further comments. In light of this re-consultation, I am satisfied that no party has been prejudiced by my consideration of the appeal proposal against the policies of the newly adopted LP.

The main issues are: • whether the proposal would be inappropriate development within the Green Belt; • if deemed inappropriate, the effect of the proposal on the openness of the Green Belt; • the effect of the proposal on the character and appearance of the host property and the locality; and • if the development would be inappropriate, whether the harm to the Green Belt by way of inappropriateness and any other harm, would be clearly outweighed by other considerations so as to amount to the very special circumstances necessary to justify it.

The appeal property is a modest sized dormer bungalow set within its own grounds. It is located within a residential suburb that contains predominantly detached single and two storey dwellings. The dwellings have a wide range of designs and have evolved over a period of time resulting in a varied pattern of buildings in terms of location, scale, and design. They utilise a varied palette of materials. Open land lies to the west, with an elevated section of the A1(M) located a short distance to the east.

The National Planning Policy Framework (the Framework) makes clear at paragraph 149 that the construction of new buildings in the Green Belt should be regarded as inappropriate, with a small number of exceptions. One of these 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 Framework defines ‘original building’ as meaning the building as it existed on 1 July 1948 or, if constructed after that date, as it was built originally.

Policy SADM 34 of the recently adopted LP, deals with development within the Green Belt and requires applicants to demonstrate that extensions and alterations to a building would not result, either individually or cumulatively, in disproportionate additions over and above the size of the original building, in terms of bulk, scale, height or massing. That said, the policy is subject to a caveat indicating that account should also be taken of the extent to which the extension and/or alteration would be consistent with the general pattern of development and character of the area and its prominence within the landscape.

The supporting text to Policy SADM 34 indicates that in determining what constitutes a disproportionate extension to a building a quantitative and qualitative assessment will be undertaken. In quantitative terms, proposals that would result in the footprint, volume and/or above ground external dimensions (height, width) of a building being 50% greater than the original building would generally be refused. However, it is recognised that each case should be assessed on its own merits as there may be circumstances in which a particular proposal may dictate that an extension in excess of 50% may be proportionate and acceptable.

The Council indicate1 that the original dwelling had a ground floor area of approximately [address] metres (m2) with a further 32 m2 at first floor level. Following the grant of planning permission2 for two garages, and a single storey side and rear extension, in 1974, which were clearly evident on the appeal premises during my site visit, a further 44 m2 of floorspace has been added. According to figures provided by the Council, the addition of the appeal proposal would extend the ground floor area by a further 46 m2 and the first floor by 126 m2. As a result, the building would have a floor area of approximately 216 m2, over and above the original dwelling. This would represent a 212% increase in floor area. The appellant does not dispute these figures and I have no reason to disagree with them. 1 Council’s delegated officer report 2 N6/1974/0720

However, assessing whether development is inappropriate, is an objective test based on size, and floor area should not be the sole basis for considering whether such a change is disproportionate. As such, it is important to consider this issue in terms of the scale, bulk, massing and the built form that would result from the changes sought.

There is no definition of ‘disproportionate’ in the Framework. The development plan provides guidance in terms of the quantum of development; however, it also provides some flexibility to take other matters into consideration, as outlined above. With these matters in mind and, having taking into account the that the original dwelling has already been extended to the side and rear, it is clear to me that the further extension of the property would result in the original dwelling being engulfed by extensions. Consequently, the proposed development would result in disproportionate additions over and above the size of the original building.

Accordingly, the proposed development represents inappropriate development in the Green Belt. Inappropriate development is, by definition, harmful to the Green Belt and should not be approved except in very special circumstances.

Paragraph 137 of the Framework indicates that openness is an essential characteristic of the Green Belt. The erection of a part single storey/part two storey side and rear extension would significantly increase the size and bulk of the building. The cumulative impact of the appeal proposal and previous extensions means that there would be a loss of openness to the Green Belt and therefore harm to the Green Belt would result.

Policy SP 9 of the LP requires, amongst other matters, that new development should respect neighbouring buildings and the surrounding context in terms of height, mass and scale. It also seeks high quality architectural design that creates coherent and attractive forms and elevations and uses high quality materials.

In addition, the Supplementary Design Guidance produced by the Council in 2005 indicates, at paragraphs 5.2 i) and ii), that extensions should be designed to complement and reflect the design and character of the dwelling, be subordinate in scale and not reduce the space around the dwelling to such an extent that it looks cramped on its site. The spacing of buildings adjacent to, and in the locality of the site, should also be reflected.

The original building has been extended in the past, with the addition of flat roofed side and rear extensions, which provides garaging and living accommodation for the occupants. The addition of a part single storey/part two storey side and rear extension, together with remodelling of the roof, would significantly increase the amount of accommodation provided. In doing so the property would take on a more coordinated appearance, with the roof design being consistent across the front elevation and the existing flat roofed extensions being subsumed into the main body of the building. However, the side extensions, together with the introduction of bonnet hips in lieu of the full hipped roof of the original dwelling, would significantly increase the bulk of the roof. There would be a corresponding increase in the scale and mass of the host property when considered as a whole. Furthermore, it would reduce the gap between the host property and its neighbours, at first floor and roof level, thereby presenting a less spacious feel to the property within its grounds.

The proposed first floor extensions to the rear of the property would incorporate gable roofs and would add further bulk to the property. More particularly they would result in the introduction of features that are not in keeping with the hipped roof design of the main part of the dwelling. That said, any views of these features would be limited and localised, and as a result there would not be a significant impact on the streetscene.

I have taken into account the Council’s concerns regarding the triangular design of the dormer windows proposed for the front elevation. In this regard I note the Councils reference to other properties in the locality, some of which have been remodelled, leading to contemporary designs being introduced into the streetscene. On my site visit I saw the wide range of designs of properties, including some that could be described as being contemporary. In particular I noted the triangular dormer features that had been introduced at No 39, which appeared to be similar to those proposed in the appeal development. Therefore, whilst accepting that dormers in the locality are predominantly flat roofed, or of a more traditional square design with pitched roofs, other forms of roof alteration have also been accepted. Consequently, I am not persuaded that the introduction of dormers with a triangular design would have a significant adverse impact on the character and appearance of the property or the area.

The appellant has referred to several examples of other extensions to dwellings in [address], which also fall within the Green Belt. However, from what I saw on my site visit, each of the examples referred to were subtly different from the appeal proposal, in terms of their siting and design. Moreover, I have not been provided with plans of those schemes or substantive evidence to show the circumstances that prevailed at the time they were permitted. Consequently, they do not provide a justification for the proposed development. In any event each application has to be considered on its own merits, having regard to its particular site circumstances, development plan policies that are in force at the time, and all other material considerations.

Taking all of these matters together I find that the alterations to the roof, together with the size and design of the side extensions, would cause harm to the character and appearance of the dwellinghouse, and the area in which it is located. Consequently, the proposal would be contrary to policy SP 9 of the LP, as set out above, and the SPG.

The Framework makes it clear, at paragraph 148, that substantial weight is given to any harm to the Green Belt. It establishes that ‘very special circumstances’ will not exist unless the potential harm to the Green Belt by reason of inappropriateness, and any other harm, is clearly outweighed by other considerations.

The Town and Country Planning (General Permitted Development) Order 2015 (as amended) (GPDO) entitles the owner of the property to carry out a variety of extensions to the dwelling. The appellant has provided evidence of two permissions relating to the appeal property. The first permission3 relates to a certificate of lawfulness for the erection of a single storey side extension to either side of the dwelling, with roof alterations including a hip to gable extension either side of the existing roof and the insertion of a dormer window in the rear roof slope. The second permission4 relates to a prior approval for the erection of a single storey rear extension measuring 8m in depth, 2.5m in height and 2.5m to the eaves.

The appellant asserts that both of the ‘permitted’ extensions could be built, as they would not touch, and therefore they represent a realistic fall-back position in the event that the appeal is dismissed. He also suggests that the size and volume of the appeal proposal would only be marginally greater than the ‘permitted’ extensions. The Council accept that the extensions provide a fall-back position, however they do not accept that the developments permitted could be built together. They make reference to Schedule 2, Part 1 Class A and B of the GPDO, but provide no substantive evidence to back up their claim. That said, the issue of whether both ‘permitted’ extensions could be carried out together, without further permission, is not a matter before me for consideration.

Even if both ‘permitted’ development schemes could be built without the need for further consent, the appeal proposal would have a greater bulk and massing than them, as it proposes a greater quantum of development at first floor level. That said, it would not raise the ridge height, the footprint of the resultant building would be less, it would have a narrower front elevation and it would avoid the introduction of large areas of flat roof. Therefore, it would appear more compact and better designed than the ‘permitted’ developments.

Notwithstanding the above, I am mindful of the topography of the site, which places the host property at a lower level than the adjoining highway. When seen in this context the ‘permitted’ developments would maintain a greater degree of openness to the site, by retaining low level structures, and as a consequence would allow more extensive views, between the dwellings, of the vegetation to the south. However, this needs to be balanced against the design of the building that would result from the completion of the ‘permitted’ developments which, in my view would not constitute ‘high quality’ design. In particular, they would not result in a building that is coherent, or have an attractive form or elevations, that would relate well to the character and proportions of the existing building or its surrounding context, as required by LP policy SP 9.

Accordingly, when taken as a whole, the merits of the appeal scheme, when compared with the ‘permitted’ developments is finely balanced. However, I am not persuaded that the scheme before me, or the ‘permitted’ developments, are the only options that would deliver the accommodation that the appellant desires.

In light of the above, I consider that, whilst the fall-back position is a material consideration, it attracts only limited weight in favour of the proposed development. 3 6/2021/0849/LAWP 4 6/2021/0855/PN8 Conclusion and planning balance.

The proposed development would represent inappropriate development, which is, by definition, harmful to the Green Belt. I have also found that there would be harm to the openness of this part of the Green Belt, in that it would be reduced. For the reasons set out above I also consider that the proposal would cause harm to the character and appearance of the dwellinghouse, and the area in which it is located. Moreover, I do not consider that the fall-back position presented amounts to very special circumstances which outweigh the harm to the Green Belt that I have identified, which is necessary to justify the proposal.

The proposal therefore conflicts with paragraph 148 of the Framework and [name] 1, SP 9 and SADM 34 of the Welwyn Hatfield Borough Council Local Plan 2016 – 2036, which jointly seek to protect the Green Belt from inappropriate development.

There are no other relevant material considerations worthy of sufficient weight that indicate the application should be determined other than in accordance with the development plan as a whole. For the reasons given above, I therefore conclude that the appeal should be dismissed.